The aim of this work is research dedicated to the search for new bactericidal systems for use in cosmetic formulations, dermocosmetics, or the production of wound dressings. Over the last two decades chitosan due to its special biological activity, has become a highly indispensable biopolymer with very wide application possibilities. Literature reports on the antibacterial effects of chitosan are very diverse, but our research has shown that they can be successfully improved through chemical modification. Therefore, in this study, results on the synthesis of new Schiff bases chitosan – dCsSB-SFD and dCsSB-PCA obtained using two aldehydes: sodium 4-formylbenzene-1,3-disulfonate (SFD) and 2-pyridine carboxaldehyde (PCA) respectively. Chitosan derivatives synthesized in this way demonstrate stronger antimicrobial activity. Carrying out the procedure of grafting chitosan with a caproyl chain allowed obtaining compatible blends of chitosan derivatives with κ-carrageenan, which are stable hydrogels with a high swelling coefficient. Furthermore, covalently bounded PCL improved the solubility of obtained polymers in organic solvents. With this respect, the Schiff base-containing polymers obtained in this study, with special hydrogel and antimicrobial properties are very promising materials for the potential use as a controlled-release formulation of both, hydrophilic and hydrophobic drugs in cosmetic products for skin health.

The collection of forty-nine 8-hydroxyquinoline derivatives, substituted at C5, C6 or C7, was designed and studied by computational methods of modified POM analysis, using SwissADME, Osiris and Molinspiration tool. POM analysis (Petra/Osiris/Molinspiration) and its modified version using SwissADME instead of Petra software are indisputably tools of modern chemoinformatics, often published in the professional literature as well as in the field of research of new antibacterial active compounds, developed to replace existing antibiotics that fail due to increased resistance of bacteria. NitroxolineTM and the group of 8-hydroxyquinoline derivatives with their broad antibacterial effect and the possibility of extensive derivatization of the skeleton, represent a promising direction in the research of new antibacterial active substances. Twenty 8-hydroxyquinoline derivatives were also evaluated on their antibacterial activity against eight selected G+ and G- bacterial strains with a defined resistance mechanism. All structures were in accordance with Lipinski's criteria, twenty-one structures were interesting from the point of view of individual or average value of the bioactivity prediction score and fourteen structures showed one or more mechanisms of toxicity prediction. Furthermore, eleven structures showed a low rate of GI absorption or the inability to cross the BBB barrier, fourteen substances showed a BRENK or PAIN warning, eleven substances are an undesirable substrate of P-glycoprotein and all structures predicted the same level of bioavailability and a relatively low rate of metabolism in the liver. Five structures were selected by the intersection of the POM criteria. The virtual structures 17, 25, 35 and 43 can be favored for the continuity of next study. The resulting scores of bioactivity can indicate the potential of studied structures to be used for the design and development of new active antibacterial agents.

The mechanism of ciprofloxacin action involves interference with transcription and replication of bacterial DNA, which results in elevated oxidative stress, and bacterial cell death. Vorinostat was shown to induce oxidative DNA damage. In the current work, the possibility for interactive effect of vorinotat on ciprofloxacin-induced cytotoxicity against a number of reference bacteria was investigated. Standard bacterial strains were Escherichia coli ATCC 35218, Staphylococcus aureus ATCC29213, Pseudomonas aeruginosa ATCC 9027, Staphylococcus epidermidis ATCC 12228, Acinetobacter baumannii ATCC 17978, Proteus mirabilis ATCC 12459, Klebsiella pneumoniae ATCC 13883, methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43300), and Streptococcus pneumoniae (ATCC 25923). The antibacterial activity of ciprofloxacin with or without pretreatment of bacterial cells by vorinostat was examined using disc diffusion procedure and determination of the minimum inhibitory concentration (MIC) and zones of inhibition of bacterial growth. All tested bacterial strains showed sensitivity to ciprofloxacin. When pretreated with vorinostat, significantly larger zones of inhibition and smaller MIC values were observed in all bacterial strains compared ciprofloxacin alone. As a conclusion, current results showed the possible agonistic properties for vorinostat when it is used together with ciprofloxacin. Future research will be focus on molecular mechanisms possible for such interactive effect.

The study evaluated potassium peroxymonosulfate (PPMS) efficacy against rifampicin-resistant Salmonella Infantis (rif-SI), Escherichia coli (E. coli), Salmonella Infantis (SI), Newcastle disease virus (NDV) and avian influenza virus (AIV). The assessment encompassed varied concentrations, organic material conditions, and exposure durations to comprehensively evaluate PPMS efficacy. Moreover, PPMS’s efficacy was tested on diverse carrier surfaces and clothing to evaluate its bactericidal and virucidal potential. At the recommended concentrations (1X), PPMS effectively inactivated all pathogens within 5 sec, except for NDV, which required 30 sec in the presence of organic materials. At 0.5X, PPMS successfully inactivated E. coli, AIV and NDV within 5 sec in the absence of organic material. However, rif-SI and SI necessitated 30 sec for inactivation. Most pathogens were inactivated within 30 sec, with the exception for AIV, which was inactivated within 5 sec. PPMS effectively eliminated rif-SI on all carriers within 30 sec. Moreover, at both concentrations, PPMS successfully inactivated AIV on all carriers within 30 sec, except on stainless steel at 0.5X. Furthermore, PPMS at both concentrations required 5 and 30 sec, respectively, to inactivate AIV on the rayon sheet. Therefore, due to its demonstrated efficacy against a wide range of pathogens across diverse surfaces, PPMS emerges as a crucial alternative disinfectant significantly enhancing biosecurity on and around chicken farms. found in and around animal farms, slaughterhouses, and hospitals.

The rise of antibiotic-resistant strains demands new alternatives in antibacterial treatments. Bacteriophages, with their precise host specificity and ability to target and eliminate bacteria safely, present a valuable option. Meanwhile, hydrogels, known for their excellent biodegradability and biocompatibility, serve as ideal carriers for bacteriophages. The combination of bacteriophages and hydrogels ensures heightened phage activity, concentration, controlled release, and strong antibacterial properties, making it a promising avenue for antibacterial treatment. This article provides a comprehensive review of different cross-linking methods for phage hydrogels and focuses on their application in treating infections caused by various drug-resistant bacteria.

Grapefruit and lemon pectin obtained from the respective waste citrus peels via hydrodynamic cavitation in water only are powerful, broad-scope antimicrobial alternatives to antibiotics against Gram-negative and -positive pathogens. Dubbed IntegroPectin, these pectic polymers functionalized with citrus flavonoids and terpenes show superior antimicrobial activity when compared to commercial citrus pectin. Similarly to commercial pectin, lemon IntegroPectin determined ca. 3 log reduction of Staphylococcus aureus cells, while an enhanced activity of commercial citrus pectin was detected in the case of Pseudomonas aeruginosa cells with a minimal bactericidal concentration (MBC) of 15 mg mL-1. Although grapefruit and lemon IntegroPectin share equal MBC in the case of P. aeruginosa cells, grapefruit IntegroPectin shows boosted activity upon exposure of S. aureus cells with a 40 mg mL-1 biopolymer concentration being sufficient to achieve complete killing of the bacterial cells. Insight on the mechanism of action of these biocompatible antimicrobials and their effect on bacterial cells, at the morphological level, were obtained indirectly through Fourier Transform Infrared spectroscopy and directly through scanning electron microscopy. In the era of antimicrobial resistance, these results are of great societal and sanitary relevance as they open new avenues to develop innovative antimicrobials for the treatment of polymicrobial infections unlikely to develop drug resistance.

Ti and its alloys are the most commonly used materials for biomedical applications. However, bacterial infection after implant placement is still one of the significant rising complications. Therefore, the application of the antimicrobial agents into implant surfaces to prevent implant-associated infection has attracted lots of attention. Scientific papers have shown that inorganic antibacterial metal element (e.g. Ag, Cu, Zn) can be introduced to implant surfaces with the addition of metal nanoparticles or metallic compounds into electrolyte via micro-arc oxidation (MAO) technology. In this review, the effects of the composition and concentration of electrolyte and process parameters (e.g. voltage, current density, oxidation time) on morphological characteristics (e.g. surface morphology, bonding strength), antibacterial ability and biocompatibility of MAO antimicrobial coating were discussed in detail. Anti-infection and osseo-integration can be simultaneously accomplished with the selection of the proper antibacterial elements and operating parameters. Besides, MAO assisted by magnetron sputtering (MS) to endow Ti-based implant materials with superior antibacterial ability and biocompatibility was also discussed. Finally, the development trend of MAO technology in the future was forecasted.

In this study, Cu2O nanoparticles were synthesized using the sol-gel technique and subsequently functionalized with extracts from plants of the Rauvolfioideae subfamily and citrus fruits. Com-prehensive characterization techniques, including UV-Vis spectroscopy, FT-IR, XRD, BET, SEM, and TEM, were employed to evaluate the structural and surface properties of the synthesized nanoparticles. The results demonstrated that both functionalized Cu2O nanoparticles exhibit mesoporous structures, as confirmed by nitrogen adsorption-desorption isotherms and pore size distribution analysis. The Green Extract functionalized nanoparticles displayed a more uniform pore size distribution compared to those functionalized with the Orange Extract. The study un-derscores the potential of these functionalized Cu2O nanoparticles for applications in drug de-livery, catalysis, and adsorption processes, highlighting the influence of the functionalization method on their textural properties and performance in antibacterial efficacy.

Today, polymeric Drug Delivery Systems (DDS) appear as an interesting solution against bacterial resistance, having great advantages such as low toxicity, biocompatibility, and biodegradability. In this work, two polyketones (PK) have been post-functionalized with taurinate (PKT) or sulfanilate (PKSK) and employed as biocompatible carriers for Vancomycin against bacterial infections. Mod-ified PKs were easily prepared by Paal-Knorr reaction and loaded with Vancomycin at variable pH. All polymers were characterized by FT-IR, DSC, TGA, SEM and elemental analysis. Antimicrobial activity was tested against Gram positive Staphylococcus aureus ATCC 25923 and correlated to the different pH used for its loading (between 2.3 and 8.8). Distinctively, minimum inhibitory con-centrations achieved with PKT and PKSK loaded with Vancomycin are similar, 0.23μg/mL and 0.24μg/mL respectively, i.e. six times lower that Vancomycin alone. The use of post-functionalized aliphatic polyketones has thus been demonstrated to be a promising way to obtain very efficient polymeric DDS.

Although a lot of research has been carried out on hand sanitizer as an effort to prevent Covid-19, there is still limited research on non-alcoholic hand sanitizer lotion from the brown algae Scytosiphon lomentaria (S. lomentaria) as a raw material that provides antibacterial effects and maintains healthy skin. Therefore, this study aimed to analyze microbial inhibitory ability, physical and chemical characteristics of hand sanitizer lotion made from S. lomentaria algae. S. lomentaria powder was tested for phytochemicals, total phenolic content, free radical scavenging activity (IC50), and antibacterial tests. S. lomentaria slurry was prepared by adding distilled water (1:1) for lotion preparations in four treatment groups, such as normal control (lotion base without adding algae), lotion with the addition of algae 20%, 30%, and 40%. The lotion preparations for each treatment group were tested for antibacterial activity of Staphylococcus aureus and Escherichia coli, phytochemicals, pH, adhesion, spreadability, homogeneity, emulsion type, and hedonic. S. lomentaria powder contains bioactive polyphenolic compounds with a total phenolic content of 117.70±1.40 mg GAE/g dry weight and an IC50 value of 455±3.4 ppm, while lotion with the addition of S. lomentaria contains polyphenols and saponins The best treatment was shown by 40% S. lomentaria hand sanitizer lotion with inhibition of 6.30 ± 0.64 mm E. coli, 6.85 ± 1.12 mm S. aureus, hedonic test for color, texture and absorption with likes to likes very much level, neutral pH, greenish-white color, O/W emulsion type, high adhesion, homogeneous, and easily absorbed by the skin. This research can be an alternative reference in making non-alcoholic hand sanitizer lotion that is safe for the skin.

In recent years, bacterial resistance to conventional antibiotics has become a major concern in the medical field. The global misuse of antibiotics in clinics, personal use, and agriculture has accelerated this resistance, making infections increasingly difficult to treat and rendering new antibiotics ineffective more quickly. Finding new antibiotics is challenging due to the complexity of bacterial mechanisms, high costs and low financial incentives for the development of new molecular scaffolds, and stringent regulatory requirements. Additionally, innovation has slowed, with many new antibiotics being modifications of existing drugs rather than entirely new classes. Antimicrobial peptides (AMPs) are a valid alternative to small molecule antibiotics offering several advantages, including broad-spectrum activity and a lower likelihood of inducing resistance due to their multifaceted mechanisms of action. However, AMPs face challenges such as stability issues in physiological conditions, potential toxicity to human cells, high production costs, and difficulties in large-scale manufacturing. A reliable strategy to overcome the drawbacks associate with the use of small molecule antibiotics and AMPs is the combination therapy, namely the simultaneous co-administration of two or more antibiotics or the synthesis of covalently linked conjugates. This review is intended to cover and critically analyze the design, synthetic strategies, antibacterial activity and, when possible, the cytotoxicity of antibiotic-AMPs conjugates.

Abstract: Conventional antibiotic and multidrug treatments become less and less effective and a discovery of new effective and safe antibacterial agents got a global priority. The returning to the natural antibacterial product is relatively new current trend. Terrestrial biota is a rich source of biologically active substances whose antibacterial potential was not fully utilized. Aim of this review is to present the current state-of-the art of terrestrial biota-derived antibacterial agents and inspired by nature treatments. It is a summary of the most important sources and new identified or modified antibacterial agents and treatments during the last 5 years. It focuses on the significance of plants- animals- and bacteria-derived biologically active agents as powerful alternatives to antibiotics as well as on the advantages of utilizing natural antibacterial molecules alone or in combinations with antibiotics. The main conclusion is that the terrestrial biota derived antibacterial products and substances open variety of new ways to modern improved therapeutic strategies. New terrestrial sources of known antibacterial agents and new antibacterial agents from terrestrial biota were discovered during the last 5 years, which are under investigation together with some long ago known but now surviving their renaissance for the development of new medical treatments. Use of natural antibacterial peptides as well as combinational therapy by commercial antibiotics and natural products outlines as the most promising for treating of bacterial infections. In vivo testing and clinical trials are necessary to reach clinical application.

Due to the deteriorating state of surface waters and the resulting reduction in their availability for the population, efforts have been undertaken to develop a biodegradable or compostable water filtration system capable of reducing the amount of harmful bacteria in this environment. The aim of this research was to develop nonwovens using the classic needle-punching method with commercially available polylactide (PLA) polymer, and subsequently, to select appropriate concentrations of modifiers to create systems with antibacterial properties. The resulting composites could potentially serve as filtration materials for the purification of surface waters. Nanoparticles such as zinc oxide, titanium dioxide, and silver were employed in this research. These compounds exhibit antibacterial properties and are insoluble in water. To confirm the bactericidal activity of the additives, biological tests were conducted, and the distribution of these additives on the structure of the filtration material was examined using scanning electron microscopy (SEM) equipped with an energy dispersive spectroscopy (EDS) detector.

PirAB is a binary protein complex secreted by specific strains of Vibrio parahaemolyticus (Vp) that harbor the pVA1 virulence plasmid and express PirAVp and PirBVp toxins. PirABVp causes acute hepatopancreatic necrosis disease (AHPND), a newly emergent penaeid shrimp disease that can cause 70–100% mortality and has resulted in great economic losses since its appearance. The cy-totoxic effect of PirABVp on the epithelial cell of the shrimp hepatopancreas has been extensively reported. Our studies found that the PirBVp subunit has lectin activity and recognizes mucin-like O-glycosidic structures in the shrimp hepatopancreas. The PirAVp subunit may have a stabiliza-tion function of the binary complex. However, we also found that Vp AHPND changes the water microbiota community structure and causes a significant reduction in several bacteria, especially Neptuniibacter spp. We propose that the PirABvp toxin could exhibit a dual role: damage the shrimp hepatopancreas and kill surrounding bacteria.

Observe the synergistic effect and dose-effect relationship of Trimethoprim (TMP) on bactericidal activity with Flos Lonicerae in vitro. Microamount chessboard dilution method was conducted to determine the minimal inhibitory concentration (MIC) of Trimethoprim, Flos Lonicerae, as well as the combination of Trimethoprim and Flos Lonicerae separately against Staphylococcus aureus, Escherichia coli in vitro and Salmonella. The pour plate count method was used to determine the combined bactericidal activity of Flos Lonicerae combined with Different concentrations TMP. The results showed that the MIC values of the combination of Flos Lonicerae with TMP was much less than the MIC values of the independent use of Flos Lonicerae or TMP, The FIC values of the combination of Flos Lonicerae with TMP were between 0.5 and 1, there was additive effect between them. The bactericidal rates were fitted with least square method, the 95% confidence intervals of the optimal blending quantity about the combination of Flos Lonicerae with TMP on the test organisms were 231μg·mL^-1-249μg·mL^-1, 237μg·mL^-1-259μg·mL^-1, and 235 -259μg·mL^-1

The aim of this study was to investigate the physicochemical characterization and biological activities of chitosan (CH) based composite films with the incorporation of chestnut flower essential oil (CFEO). The composite films were prepared by casting method and characterized in terms of structural, morphological and mechanical properties via FT-IR, XRD, UV, SEM and TGA. The results proved the significantly increased water vapor permeability (WVP), heat resistance, antibacterial and antioxidant capabilities of CH-CFEO films. The incorporation of CH and CFEO enhanced the UV blocking, which made the film shield almost all UV light. Films with the tensile strength of 6.37 ± 0.41 MPa and elongation at break of 22.57 ± 0.35% were got with 6 mg mL-1 CFEO. Subsequently, the fruit preservation experiments also confirmed that the composite films could effectively extend the shelf life of bananas through their excellent water vapor and oxygen barrier. These desirable performances enable our newly developed composite films to be a remarkable packaging material to solve the fresh fruit preservation dilemma.

Recent studies have suggested significant antimicrobial properties of some metallic nanoparticles during the height of antibiotic resistance. The silver nanoparticle (AgNPs) is one of the most prominent candidates due to its noble nature and better tolerance profile in humans. The synthesis of AgNPs was carried out using silver nitrate using five different chemical reduction methods and comparing their activity with silver nitrate, also known to possess antimicrobial properties. AgNPs have been synthesized with varying combination of reducing agents, and subsequently characterized by UV-visible spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and dynamic light scattering (DLS). Chemical reduction with both trisodium citrate and sodium borohydride provided better particle size and controlled uniformity, whereas hydrogen peroxide was used as a stabilizer to increase the stability of AgNPs. The minimum bactericidal concentration (MBC) for all AgNP formulations was determined against gram-negative E. coli, and AgNPs synthesized with only trisodium citrate were found to be the most effective. The synthesized AgNPs were tested against the resistant strains of E. coli, Salmonella, Klebsiella, Bacillus, and Staphylococcus by the well diffusion method to evaluate and compare their inhibition zones and AgNPs synthesized with polyethylene glycol and polyvinyl pyrrolidine were found to be the most efficient.

The antimicrobial quantitative structure–activity relationship of plant flavonoids against Gram-positive bacteria was established in our previous works, and the cell membrane was confirmed as a major site of action. To investigate whether plant flavonoids have similar antibacterial effects and mechanisms against both Gram-negative and Gram-positive bacteria, here, the minimum inhibitory concentrations (MICs) of 37 plant flavonoids against Escherichia coli were determined using the microdilution broth method, and then the correlation between their lipophilic parameter ACD/LogP or LogD_7.40 value and their MIC was analyzed. Simultaneously, the correlation between the ACD/LogP or LogD_7.40 value and the MIC of 46 plant flavonoids reported in literature against E. coli was also analyzed. Both sets of results showed that there is a significant correlation between the LogP value and the MIC of plant flavonoids against Gram-negative bacteria. However, it is difficult to effectively predict the MIC of plant flavonoids against Gram-negative bacteria from their lipophilic parameters. By comparing two regression curves derived from plant flavonoids against Gram-negative and Gram-positive bacteria, it was further discovered that the antibacterial activities of most plant flavonoids against Gram-negative bacteria are stronger than those against Gram-positive bacteria when their LogP values are less than about 3.0, but the opposite is true when their LogP values are more than about 3.6. Moreover, this comparison also suggests that unlike mainly acting on the cell membrane of Gram-positive bacteria, plant flavonoids have multiple mechanisms against Gram-negative species, while the cell membrane is also an important action site among them. Combined with the correlation analyses between the enzyme inhibitory activity and the LogP value of the reported flavonoids, it was further suggested that DNA gyrase is another important target of plant flavonoids against Gram-negative bacteria.

In this study electrophoretic deposition (EPD) technique is used to prepare chitosan-based coatings with enhanced antibacterial activity suitable for bone implants applications. We designed, prepared and compared physic-chemical and biological properties of coatings obtained with commercial chitosan, chitosan enriched with silver nanoparticles and chitosan obtained from insects. With the aim to consider the sustainability issue, silver nanoparticles were directly prepared in the chitosan solution by laser ablation in liquid technique, avoiding the use of chemicals and limiting the production of wastes. Moreover, a sustainable source of chitosan such as Hermetia Illucens exuviae was considered. The EPD process was optimized by adjusting parameters like voltage and deposition time to achieve ideal coating thickness and adhesion. The prepared films were characterized by spectroscopic and microscopic techniques such as SEM, XRD, and FTIR. Antimicrobial tests against E. coli and S. aureus revealed that silver nanoparticles enhanced the antibacterial properties of the polymer, whereas biological evaluation using the WST8 test on MG63 human osteoblasts-like cells showed that all coatings are non-toxic. Finally, chitosan obtained from insect showed comparable properties with respect to the commercial polymer, suggesting it could replace seafood-derived chitosan in biomedical applications, whereas the Ag@chitosan composite demonstrated superior antibacterial activity without compromising its biocompatibility.

Potentially, traditional medicine is used to manage multidrug resistance (MDR) bacterial infections. This study determined the antioxidant and antibacterial activities of Thymus schimperi (Ts), Rhamnus prinoides (Rp) and Justicia schimperiana (Js) from Addis Ababa against MDR-Uropathogenic Bacteria. Hydromethanolic extracts were prepared. Quantitative determination of phytochemicals and DPPH, ABTS and FRAP assays for antioxidant activities were carried out. In vitro, antibacterial activity and minimum inhibitory concentration (MIC) were performed. Ts had the highest total phenolic (TPC), flavonoid (TFC) and proanthocyanidin content. GC-MS analyses identified 14 bioactive-compounds: in Ts extract, with hexanedioic acid, bis(2-ethylhexyl) ester, thymol, and o-cymen-5-ol being the most predominant, respectively; in Rp extract (6 compounds; hexanedioic acid, bis(2-ethylhexyl) ester, β-D-glucopyranoside, methyl and desulphosinigrin respectively); and in Js extract (5 bioactive-compounds: hexanedioic acid, mono (2-ethylhexyl) ester, debrisoquine, and 8,11,14-heptadecatrienoate, methyl ester) being predominant, respectively. The extracts' TPC showed a strong negative correlation with the DPPH assay (r= -0.999; p=0.023), while its TFC correlated significantly with the ABTS assay (r=0.999; p= 0.032). Ts showed the highest antibacterial activity against clinical isolates of Escherichia coli and Klebsiella pneumoniae ESBL at 1000 mg/mL, and TS had the lowest MIC (4 mg/mL) among evaluated extracts against E. coli (ATCC25922). In conclusion, Ts and Rp showed activity against patient-isolated MDR-uropathogenic E. coli and K. pneumoniae ESBL.

The key objective of the experiment was to show the environmental based of copper nanoparticles which counters the growth of bacterial pathogens such as Pseudomonas aeruginosa, and Staphylococcus aureus. To begin with the experiments, root extract of Asparagus racemosus was used to synthesise Copper nanoparticles. To confirm the formation of Cu-NPs, it was subjected to characterization such as Ultra Violet analysis, X-ray Diffraction method, Fourier Transform Infrared Spectroscopy and Scanning electron microscope images. Later the antibacterial activity of Cu-NPs was studied by incorporating it into two bacterial pathogens (Pseudomonas aeruginosa and Staphylococcus aureus). The outcome displayed a satisfactory antibacterial activity against the bacterial pathogens by the biosynthesized copper nanoparticles. To boost up the enzyme inhibition property of the Cu NPs, Antioxidant and Antidiabetic assay were also performed. The biosynthesised Cu NPs displayed a satisfied result in Antifouling function. The result was used assessed with green algae bloom water.

Management of chronic inflammation and wounds has always been a key issue in the pharmaceutical and healthcare sector. Curcumin (CCM) is an active ingredient extracted from turmeric rhizomes that has antioxidant, anti-inflammatory, and antibacterial activities, thus showing significant effectiveness toward wound healing. However, its shortcomings such as poor water solubility, poor chemical stability and fast metabolic rate limit its bioavailability and long-term use. In this context, hydrogels appear to be a versatile matrix for carrying and stabilizing drugs due to the biomimetic structure, soft porous microarchitecture, and pleasant biomechanical properties. The drug loading/releasing efficiencies can also be controlled by use of highly crystalline and porous metal organic frameworks (MOFs). Here, a flexible hydrogel composed of sodium alginate (SA) matrix and CCM-loaded MOFs was constructed for long-term drug release and antibacterial activity. The morphology and physicochemical properties of composite hydrogels were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet visible spectroscopy (UV-Vis), Raman spectroscopy and mechanical property tests. The results showed that the composite hydrogel was highly twistable and bendable to mechanically comply with human skin. The as-prepared hydrogel could capture efficient CCM for slow drug release as well as effective killing of bacteria. Therefore, such composite hydrogel is expected to provide a new management system for chronic wound dressings.

The present study aims to evaluate the antibacterial activity of five commercially available essential oils (EOs): Lavender (LEO), Clove (CEO), Oregano (OEO), Eucalyptus (EEO), and Peppermint (PEO) against the most-known MDR Gram-positive and Gram-negative bacteria - Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853) - alone and in various combinations. Gas Chromatography-Mass Spectrometry (GC-MS) analysis established their complex composition. Then, the antibacterial activity was investigated in vitro by diffusimetric antibiogram method, using sterile cellulose discs with Ø 6 mm impregnated with 10 µl of sample and sterile borosilicate glass cylinders loaded with 100 µl of sample; MIC (µg/mL) for each EO was calculated from IZD values (mm) measured after 24 hours. The following EO combinations were evaluated: OEO+CEO, CEO+EEO, CEO+PEO, LEO+EEO, and EEO+PEO. Then, the influence of each dual combination on 3 conventional antibacterial drugs – Neomycin (NEO), Tetracycline (TET), and Bacitracin (BAC) - activity was investigated. The most active EOs against S. aureus and E. coli were LEO and OEO (IZD = 40 mm). They were followed by the CEO and EEO (IZD = 20-27 mm); PEO exhibited the lowest antibacterial activity (IZD = 15-20 mm). EEO alone showed the highest inhibitory activity on P. aeruginosa (IZD = 25-35 mm). It was followed by the CEO, LEO, and EEO (IZD = 7-11 mm), while PEO proved no antibacterial action against it (IZD = 0 mm). Only one synergic action was recorded (OEO+CEO against P. aeruginosa); EEO+PEO revealed partial synergism against S. aureus and CEO+PEO additive behavior against E. coli. Two triple associations with TET showed partial synergism against E. coli, and the other 2 ones (with NEO and TET) evidenced the same behavior against S. aureus; all contained EEO+PEO or CEO+PEO. Most combinations reported indifference. However, numerous cases were of antagonism between constituents included in double and triple combinations, and EOs with the strongest antibacterial activities belong to the highest antagonistic combinations. A consistent statistical analysis supports our results, showing that EOs with moderate antibacterial activities could generate combinations with higher inhibitory effects based on synergistic or additive interactions.

Preventing the occurrence of secondary caries serves as one of the significant issues in dental clinic, thus make it indispensable to improving the properties of conventional composite resin (CR) by developing a novel CR. In present study, two groups of experimental CRs loaded with different contents of fluoride-doped nano-zirconia fillers (25 wt% and 50 wt%) were fabricated. The surface topography, mechanical performance, fluoride release, antibacterial effect, aging property and cytotoxicity of the experimental CRs were evaluated subsequently. A uniform distribution of the F-zirconia fillers over the whole surface of resin matrix could be observed. The experimental CRs showed continuous fluoride release within 28 days, which was positively correlated with the content of F-zirconia fillers. Moreover, the amount of fluoride release increased in the acidic buffer. Addition of F-zirconia fillers could improve the color stability, wear resistance and microhardness of the experimental CRs, without reducing the flexure strength. Furtherly, the fluoride ions released continuously from the experimental CRs resulted in effective contact and antibacterial properties, while they showed no cytotoxicity. As a consequence, considerations can be made to employ this new kind of composite resin loaded with fluoride-doped nano-zirconia fillers to meet clinical requirements when the antimicrobial benefits are desired.

Antibacterial bone cements (ABCs), such as antibiotic-loaded bone cements (ALBCs), have been widely utilized in clinical treatments. Currently, bone cements loaded with vancomycin, gentamicin, tobramycin, or clindamycin are approved by the US Food and Drug Administration. However, traditional ALBCs exhibit drawbacks like burst release and bacterial resistance. Therefore, there is a demand for the development of antibacterial bone cements containing novel agents. In this review, we summarize the latest advancements in ABCs. More importantly, we provide an overview and outlook on novel antibacterial agent-loaded bone cements, including metallic antibacterial agents, pH-switchable antibacterial agents, cationic polymers, N-halamines, non-leaching acrylic monomers, antimicrobial peptides, etc. Offering novel perspectives for designing ABCs and treating bone infections.

Cancer and infectious diseases are two of the world's major public health problems. Gemcitabine (GEM) is an effective chemotherapeutic agent against several types of cancer. In this study, we developed macrocapsules by incorporating GEM into a chitosan matrix blended with magnetite and zeolite. The physico-chemical characterization of the precursor materials and the new delivery system was carried out by HRTEM-ED, XRD, FESEM-EDS, FT-IR, TGA, encapsulation efficiency (%E.E.) and release profiles at pH 7.4 and 5.0. Cell viability tests on A549 and H1299 cell lines and microbiological properties against staphylococcal strains were performed. Our results revealed the successful production of hemispherical capsules with an average diameter of 1.22 mm, a rough surface and characteristic FT-IR material interaction bands. GEM encapsulation rates exceeded 80%, and release profiles were well-controlled over 24 hours at tested pH levels. Notably, cell viability in H1299 cells was lower than the free GEM control. Moreover, the formulation exhibited potent antimicrobial activity against Staphylococcus epidermidis, highlighting its dual action as a chemotherapeutic and antimicrobial agent. This dual effect underscores the potential of these macrocapsules as innovative delivery system for treating lung cancer in patients who are also at risk of infectious diseases and who are immunosuppressed.

Self-healing, stretchable and moldable hydrogels have a great potential application in tissue engineering and soft robotics. Despite great success in reported hydrogels, it is still a great challenge to construct the moldable hydrogels with an ultrafast self-healing performance. Herein, the dynamic double network (DN) composite hydrogels (PBLH) with ultrafast self-healing, stretchable and moldable were successfully constructed by poly (vinyl alcohol) (PVA), borate, ε-poly-L-lysine (EPL) and hyaluronic acid (HA) based on an efficient one-pot method. Fourier transform infrared spectroscopy, X-Ray diffraction and rheological measurements confirmed the formation of dynamic double networks among PVA, B, EPL and HA through the cross-linking of dynamic borate bonds, electrostatic interaction and hydrogen bonding. Having fabricated the dynamic double network structure, the damage gap of the composite hydrogels can heal within 1 min, presenting an excellent self-healing ability. Simultaneously, the DN hydrogels can be molded to various shapes and the length of the DN hydrogels can be stretched to 15 times than original length. In addition, the DN hydrogels exhibited an excellent antibacterial property against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Our results illustrated that the DN composite hydrogels not only retain the advantages of traditional hydrogels, but also possess ultrafast self-healing, outstanding stretchable and antibacterial properties, presenting a prospective candidate for constructing biomedical materials.

Antimicrobial resistance (AMR) is a growing public health issue worldwide that affects the world economy. The concern associated with this issue increased during the COVID-19 pandemic. The misuse of antibiotics during the COVID-19 pandemic will have catastrophic implications for the control of AMR. In 2019, the coronavirus illness COVID-19 first appeared in China. COVID-19 infection is a surface-to-surface communicable disease. It is considered the most vital global health disaster of the century. It has rapidly spread around the world and is the greatest challenge for humankind. This chapter discusses the origin, symptoms, transmission, treatment, and recommendations of the COVID-19 disease.

Over the years, chitosan has been the subject of numerous studies and has gained significant popularity as a biomaterial due to its various characteristics, including biocompatibility, biodegradability, and bioactivity. In this work, chitosan fibres surface was modified with ursolic acid to improve their antibacterial properties by wet impregnation method. Five specimens of chitosan fibres were immersed in ursolic acid (UA) solution for varying immersion times of 1, 2, 4, 6, and 8 hours. Characterization was carried out by means of FTIR, SEM, UV-Vis spectroscopy; the results indicated an ongoing chemical reaction between chitosan and ursolic acid resulting in changes to the chemical structure. After 2 hours, the absorbance ratio remained constant; suggesting that the reaction had reached completion and the chemical structure of the sample remained stable. Antibacterial tests were performed on the resulting chitosan fibres against two bacterial strains. The fibres without ursolic acid did not exhibit any noteworthy antibacterial activity against either strain. However, the chitosan fibres modified with ursolic acid showed significant and almost strong antibacterial activity against the Gram-positive strain, S. aureus. These results suggest that chitosan fibres modified with ursolic acid could have potential applications as antibacterial materials, particularly against Gram-positive bacteria.

Graphene-based nanomaterials have emerged as promising materials for a wide range of applications.. Therefore, in the last years carbon nanoparticles have attracted great attention due to their low toxicity, high biocompatibility and easy preparation. Recently, N-doped carbon nanoparticles have been shown to have improved antibacterial activity over the undoped nanomaterial, but it is difficult to find correlations between the structure of the nanoparticle and its antibacterial activity. With this purpose, here, we analyze the effect of both, the nanoparticle size and the surface chemical composition of four N-doped carbon nanoparticles on the growth of Escherichia coli bacteria. Our results were analyzed using a Ligand-Substrate model based on the Monod´s equation, which allows us to interpret the dependence of the nanoparticle-bacteria affinity with the nanomaterial structure.

Biofilm-associated bacterial infections are the major reason for treatment failure in many diseases including burn trauma infections. Uncontrolled inflammation induced by bacteria leads to materiality, tissue damage and chronic diseases. Specialized proresolving mediators (SPMs), including maresin-like lipid mediators (MarLs), are enzymatically biosynthesized from omega-3 essential long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA) by macrophages and other leukocytes. SPMs exhibit strong inflammation-resolving activities, especially inflammation provoked by bacterial infection. In this study, we explored the potential direct inhibitory activities of three MarLs on gram-positive (Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria in their biofilms that are leading bacteria in burn trauma related infections. We also examined the effects of MarLs on the bactericidal activities of a typical broad-spectrum antibiotics carbenicillin on these bacteria in their preformed biofilms. The results revealed that MarLs combined with carbenicillin can inhibit the survival of gram-positive and gram-negative bacteria in their biofilms although MarLs alone did not exhibit bactericidal activity. Thus, our findings suggest that the combination of MarLs and carbenicillin can lower the antibiotic requirements to kill the bacteria in preformed biofilms.

The increasing emergence of multidrug resistant (MDR) pathogens causes difficult-to-treat infections, with long-term hospitalizations and high incidence of death, thus representing a global public health problem. To manage MDR bacteria bugs, new antimicrobial strategies are necessary, and their introduction in practice is a daily challenge for scientists in the field. An extensively studied approach to treat MDR infections consists in inducing high levels of reactive oxygen species (ROS) by several methods. Although further clinical investigations are mandatory on the possible toxic effects of ROS to mammalian cells, clinical evaluations are extremely promising, and their topical use to treat infected wounds and ulcers, also in presence of biofilm, is already clinically approved. Biochar (BC) is a carbonaceous material obtained by pyrolysis of different vegetable and animal biomass feedstocks, at 200−1000 °C in limited presence of O2. Recently, it has been demonstrated that BC capability of removing organic and inorganic xenobiotics is mainly due to the presence of persistent free radicals (PFRs), which can activate oxygen, H2O2 or persulfate in the presence or not of transition metals by electron transfer thus generating ROS, which in turn degrade pollutants by advanced oxidation processes (AOPs). In this context, the antibacterial effects of BC containing PFRs have been demonstrated by some authors against Escherichia coli and Staphylococcus aureus, thus giving birth to our idea of the possible use of BC-derived PFRs as a novel method capable of inducing ROS generation for antimicrobial oxidative therapy. Here, the general aspects concerning ROS physiological and pathological production and regulation, and the mechanism by which they could exert antimicrobial effects have been reviewed. The methods currently adopted to induce ROS production for antimicrobial oxidative therapy have been discussed. Finally, for the first time, BC-related PFRs have been proposed as a new source of ROS for antimicrobial therapy via AOPs.

Hypervirulent Klebsiella pneumoniae (hvKp) is a variant that has been increasingly linked to severe, life threatening infections including pyogenic liver abscess and bloodstream infections. HvKp belonging to the capsular serotypes K1 and K2 have been reported worldwide, however very scarce studies are available on the their genomics and virulence. In the current study we report four hypermucoviscous hvKp ESBL clinical strains of capsular serotype K1 and K2 isolated from pus and urine of critically ill patients in tertiary care hospitals in Oman. These strains belong to diverse sequence types (STs) namely ST-23(K1), ST-231(K2), ST-881(K2), and ST-14(K2). To study their virulence, Galleria Mellonella model and resistance to human serum killing were used. The G. mellonella model revealed that the K1/ST-23 isolate is the most virulent as 50% of the larvae died in the first day, followed by isolate K2/ST-231 for which 75% of the larvae died in the second day and isolate K2/ST-14 for which 50% of the larvae died in the second day. Resistance to human serum killing showed there was complete inhibition of bacterial growth of all four isolates by the end of the first hour and up to the third hour. For ST-23(K1), ST-231(K2), ST-881(K2), and ST-14(K2), there was a gradual decrease in the number of colonies up to the second to third hour, which indicates neutralization of bacterial cells by the serum components. However, this was followed by sudden increase of bacterial growth, indicating possible resistance of bacteria against human serum bactericidal activity. Whole genome sequencing (WGS) revealed that hvKp strains display unique genetic arrangement of k-loci. Whole genome SNP-based phylogenetic analysis revealed that these hvKp isolates are phylogenetically distinct, belonging to diverse clades and belong to different STs in comparison to global isolates. This is the first report from Oman detailing the WGS of hvKp clinical isolates and assessing their resistance and virulence genomics, which reinforce our understanding of their epidemiology and dissemination in clinical settings.

The use of nanoparticles as antimicrobial agents can be one of the strategies to overcome the tendency of microbes to become resistant to antibiotics’ action. In this study, two composites ZnO/Au and ZnO/Ag, having 1% wt. of noble metal content, were synthesized by simple aqueous solution methods. The structure and morphology of the resulting nanocomposites were analyzed by standard structural and optical characterization methods. The formation of Au NPs and Ag NPs in these experiments was also discussed. The antimicrobial properties of ZnO, ZnO/Au and ZnO/Ag nanomaterials were investigated against Gram-negative bacteria (Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus). The electrostatic interaction between ZnO and noble metals nanoparticles have contributed to a better visible light adsorption, which led to an enhanced antimicrobial activity. The photocatalytic tests indicated an improvement in photocatalytic degradation of the methylene blue (MB) under UV irradiation using ZnO/Au and ZnO/Ag nanocomposites compared to bare ZnO. The introduction of noble metallic nanoparticles in ZnO matrix proved to be an effective strategy to increase their antimicrobial activity against P. aeruginosa and S. aureus and their photocatalytic activity evaluated through the degradation of MB dye. Comparing the enhancing effects of Au and Ag, it was found that ZnO/Au was a better antimicrobial agent while ZnO/Ag was more effective photocatalyst under UV irradiation.

Egg white lysozyme was modified by chemical methods using organic acids. Caffeic acid and p-coumaric acid in organic acids were used as modifiers, and 1-Ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxy succinimide were used as dehydration condensation agents during modification. A certain degree of modified lysozyme was obtained through appropriate modification conditions. The antibacterial properties and structure of the obtained two organic acid modified lysozymes were compared with natural enzymes. The results showed that compared with the natural enzyme, the activity of modified lysozyme decreased, but the inhibitory effect on Gram-negative bacteria was enhanced. The minimum inhibitory concentrations of caffeic acid modified enzyme and p-coumaric acid modified enzyme on Escherichia coli and Pseudomonas aeruginosa were 0.5 mg/mL and 0.75 mg/mL, respectively. However, the antibacterial ability of modified lysozyme to Gram-positive bacteria was lower than that of natural enzyme. The minimum inhibitory concentration of caffeic acid modified enzyme and p-coumaric acid modified enzyme to Staphylococcus aureus and Bacillus subtilis was 1.25 mg/mL. The peak fitting results of the amide-I band (1600 cm-1-1700 cm-1) absorption peak in the infrared spectroscopy showed that the content of the secondary structure of the two modified enzymes obtained after modification was different from that of natural enzymes.

The microbial contamination in food packaging have been a major concern that paved the way for the search for natural based new anti-microbial agents, such as modified α-mangostin. In the present work, twelve synthetic analogs were obtained via semi-synthetic modification of α-mangostin by Ritter reaction, reduction by palladium-carbon (Pd-C), alkylation, and acetylation. The evaluation of the anti-microbial potential of the synthetic analogs showed higher therapeutic value than the parent molecule. The anti-microbial studies proved that I E showed higher antibacterial activity whereas I I showed most significant antifungal activity. Due to their microbial properties, modified α-mangostin can be utilized as active anti-microbial agents in food packaging.

To date, various chimeric lysins have been developed as efficacious antibiotics against multidrug-resistant bacteria, but direct comparisons of their antibacterial activities have been difficult due to the preparation of multiple recombinant chimeric lysins. Previously, we reported an E. coli cell-free expression method to screen better chimeric lysins against Staphylococcus aureus, but we still needed to increase the amounts of expressed proteins enough to be able to detect them non-isotopically for quantity comparisons. In this study, we improved the previous cell-free expression system by adding a previously reported artificial T7 terminator and reversing the different nucleotides between the T7 promoter and start codon to those of the T7 phage. The new method increased the expressed amount of chimeric lysins enough for us to detect them using Western blotting. Therefore, the qualitative comparison of activity between different chimeric lysins has become possible via the adjustment of the amount variables between samples without protein purification. We applied it to select more active chimeric lysins derived from our previously reported chimeric lysin (ALS2). Finally, we compared the antibacterial activities of our selected chimeric lysins with reported chimeric lysins (ClyC and ClyO) and lysostaphin, and determined the rank orders of antibacterial activities on different S. aureus strains in our experimental conditions.

The increasing emergence of multidrug resistant (MDR) pathogens, due to antibiotics misuse, translates in obstinate infections, with high morbidity and high-cost hospitalizations. To oppose these MDR superbugs, new antimicrobial options are necessary. Although both quaternary ammonium (QASs) and phosphonium salts (QPSs) possess antimicrobial effects, QPSs have been studied at lesser extent. Recently, we have successfully reported on the bacteriostatic and cytotoxic effects of a triphenyl phosphonium salt against MDR isolates of Enterococcus and Staphylococcus genus. Here, aiming at finding new antibacterial devices possibly bactericidal towards a broader spectrum of clinically relevant bacteria, responsible for severe human infections, we synthesized a water-soluble, sterically hindered quaternary phosphonium salt (BPPB). It encompasses two triphenyl phosphonium groups linked by a C12 alkyl chain, thus embodying the characteristics of molecules known as bola-amphiphiles. BPPB was characterized by ATR-FTIR, NMR and UV spectroscopy, FIA-MS (ESI), elemental analysis and potentiometric titrations. Optical and DLS analyses evidenced BPPB tendency to self-forming spherical vesicles in solution (45 nm by DLS), having a positive zeta potential (+18 mV). The antibacterial effects of BPPB were for the first time assessed against fifty clinical isolates of both Gram-positive and Gram-negative species. Excellent antibacterial effects were observed on all strains tested, involving all the most worrying species included in ESKAPE bacteria. The lowest MICs were 0.250 µg/mL, while the highest ones (32 µg/mL) were observed on MDR Gram-negative metallo-β-lactamase-producing bacteria and/or species resistant also to colistin, carbapenems, cefiderocol, so that intractable with current available antibiotics. Moreover, when administered to HepG2 human hepatic and Cos-7 monkey kidney cell lines, BPPB showed selectivity indices > 10 for all Gram-positive isolated and for clinically relevant Gram-negative superbugs such as those of E. coli species, thus being very promising to be clinically developed.

Cadmium Sulfide nanoparticle (CdS-LA hybrid nanoparticles) was synthesized here by a green approach using the precursor cadmium acetate and sodium sulphide along with the extract of a plant Lathyrus aphaca L. containing the phytochemicals which were responsible for surface modification of nanoparticles. The nanoparticle was used to evaluate their inhibition potential against species of bacteria and fungi. The nanoparticles were characterized by XRD which demonstrates the hexagonal crystal structure. SEM confirms the homogenous surface appearance of the CdS-LA hybrid crystalline structure. EDX analysis confirms surface modification of nanoparticles by phytochemicals. FTIR confirmed the Cd-S linkage laterally with the related functional groups and the presence of metabolites on the surface of nanoparticles. The UV-visible spectroscopy confirmed the peak at the characteristic wavelength range but a slight shift occurred in the peak of the CdS nanoparticles due to the presence of the phytochemicals. This study particularly provides an environment-friendly strategy to synthesize the CdS nanoparticles capped by Lathyrus Aphaca L. extract that are biologically active due to the mediation of the plant extract. CdS-LA hybrid nanoparticles have shown inhibition potential against various species of bacteria and fungi and realize the biological importance of the green synthesis of nanoparticles especially mediated with the plant extract.

In this study, we report the antibacterial mechanisms of action of uniform silver nanoparticles (AgNPs) and decorated activated carbon nanocomposite (CAC-AgNPs) obtained using a green synthesis approach. The nanomaterials were characterized by ultraviolet-visible (UV-vis) absorption spectra and Fourier transform infrared (FTIR) spectra. The antibacterial activity of the as-prepared nanomaterials was evaluated against an array of bacterial strains by microdilution method, whereas their cytotoxicity profile was evaluated on Vero cells (human mammalian cells). The antibacterial mechanistic studies of active nanomaterials were carried out through bacterial growth kinetics, nucleic acid leakage test, and catalase inhibition assay. A silver nanocomposite was successfully fabricated from Croton macrostachyus-based activated carbon. The as-prepared nanomaterials exhibited antibacterial activity against an array of bacterial strains (minimum inhibitory concentration (MIC) range: 62.5 to 500 µg/mL), the most susceptible being Escherichia coli and Staphylococcus aureus. Cytotoxicity studies of the nanomaterials on Vero cells revealed that the nanocomposite (median cytotoxic concentration (CC50): 213.6 µg/mL) was less toxic than the nanoparticles (CC50 value: 164.75 µg/mL) counterpart. Antibacterial mechanistic studies unveiled that the nanomaterials induced (i) bacteriostatic activity vis-à-vis E. coli and S. aureus and (ii) inhibition of catalase in these bacteria. This novel contribution on the antibacterial mechanisms of action of silver nanocomposite from C. macrostachyus-based activated carbon might contribute to the understanding of antibacterial action of these biomaterials. Nevertheless, more chemistry and in vivo experiments, as well as in depth antibacterial mechanistic studies are warranted for the successful utilization of these antibacterial biomaterials.

Many medicinal plants and their essential oils are used to treat or prevent diseases without the risk of mutagenicity, carcinogenicity, or teratogenicity. Eucalyptus essential oils are commonly used as preservatives, flavoring agents, and in various consumer goods. Eucalyptus leaves are being widely studied due to their volatile essential oils, including 1,8-cineole, p-cymene, α and β-pinene, limonene, citronellal, citral, eudesmol, terpinen-4-ol, terpineol, α–phellanderene, and 9β-sitosterol. Among these compounds, 1,8-cineole is the most abundant. Eucalyptus leaves are rich in flavonoids and phenolic compounds and are thus a great source of antioxidants. 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays are used to measure antioxidant capacity. The antioxidant activity of Eucalyptus essential oil is stronger than that of standard antibiotics like Erythromycin, Cefixime, and Gentamicin due to the presence of significant terpenoids in addition to phenolic chemicals and flavonoids. The lower the IC₅₀ value, the higher the antioxidant potential. Phenolic compounds and flavonoids are often associated with beneficial health outcomes, including anti-inflammatory and antioxidant effects, anti-cancer properties, reduced risk of cardiovascular diseases, prevention of age-related neurodegenerative diseases, and prevention of Alzheimer’s disease. Flavonoids also play an essential role in plants, including protecting against reduction, fertility, reproduction, and infection. Due to their anti-inflammatory, anti-oxidative, and immune-modulatory properties, flavonoids are crucial for pharmacological, medical, and nutraceutical applications.

Tin (IV) oxide nanoparticles (SnO2 NPs) have received a lot of interest because of their interesting features. SnO2 NPs have proven productive in a range of fields, including water purification, supercapacitors, batteries, antibacterial and antioxidant agents, and others. SnO2-based nanoparticles found a wide range of applications after incorporating materials with varying chemical compositions. SnO2 NPs and their nanocomposites have been used effectively as antibacterial agents against various pathogenic bacteria, photocatalysts for dye degradation, and electrode materials for supercapacitors (SCs). This article covers the characteristics of SnO2 NPs, SnO2 nanocomposite materials, applications of SnO2 NPs and their composite materials, including antibacterial, energy storage, and photocatalysis, as well as some significant recent studies.

Multifunctional coatings based on Sn-Ni materials with and without titanium oxide nanoparticles (TiO2NPs) incorporation were prepared using the electrochemical deposition technique at 70°C. TiO2NPs were dispersed in the electrolyte bath, and their influence on both surface texture, crystalline phase, and properties was investigated. Various techniques such as X-ray phase analysis (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray microanalysis (EDX) were used to characterize the prepared coatings. The anti-corrosion effectiveness of the coatings was assessed using potentiodynamic polarization curves and electrochemical impedance spectroscopy in an artificial sweat medium, while the bactericidal activity of the composite coatings (the ability to induce cell death) was evaluated in accordance with ISO 27447:2009 test. The influence of the TiO2NPs on the composition, structure and properties of the deposited coatings was established. Particular attention was paid to the relationship between the anticorrosive and bactericidal properties of the coatings and their structure and composition. The synergistic effect of the various properties was investigated and discussed.

In recent years, antibacterial coatings have become a significant approach in the global fight against bacterial pathogens. Developments in materials science, chemistry and biochemistry have led to a plethora of materials and chemical compounds that have potential for creating antibacterial coatings. Nonetheless, there has been insufficient consideration given to the analysis of the techniques and technologies used to apply these coatings. Among the various inorganic coating techniques, Atomic Layer Deposition (ALD) is noteworthy. It enables the successful synthesis of high-purity inorganic nanocoatings on surfaces of complex shape and topography, while also providing precise control over their thickness and composition. ALD has various industrial applications, but its practical application in medicine is still limited. In recent years, a substantial number of papers have been published on the suggested implementation of thin films and coatings produced through ALD in medicine, notably those with antibacterial properties. The aim of this paper is to carefully evaluate and analyse the relevant literature on this subject. Simple oxide coatings, including TiO2, ZnO, Fe2O3, MgO, and ZrO2, were examined, as well as coatings containing metal nanoparticles such as Ag, Cu, Pt, and Au, and mixed systems such as TiO2-ZnO, TiO2-ZrO2, ZnO-Al2O3, TiO2-Ag, and ZnO-Ag. Through comparative analysis, we have been able to draw conclusions on the effectiveness of various antibacterial coatings of different compositions, including key characteristics such as thickness, morphology, and crystal structure. ALD has been analysed in its use for developing antibacterial coatings for various applications. Furthermore, assumptions regarding the most promising development areas have been presented.

Zingiber officinale rhizome is widely cultivated in the central region of Sudan (Gezira) and data on the biological properties of this variety grown in the Sudan climate is scarce. The study aims to comprehensively analyze the antibacterial, antioxidant, phytochemical, and GC-MS properties of Zingiber officinale (Ginger rhizome) to explore its potential applications. The in vitro antibacterial assessment of the aqueous extract of the Sudanese ginger revealed moderate activity against Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli , and Klebsiella pneumonia, as resulted from the disc-diffusion which ranged between 12.87±0.11 mm to 14.5±0.12 mm at 30 µg/disc. The minimum inhibition concentration ranged between 6.25 to 25 µg/ml, the MBC were between 25 and 50 µg/ml, and the MBC/MIC exhibited its bactericidal effect against all tested bacteria. The phytochemical screening revealed the presence of various chemical constituents such as saponins, flavonoids, glycosides, alkaloids, steroids, terpenoids, and absence of tannins in the Sudanese ginger rhizome. Furthermore, the GC-MS study of ginger rhizome identified 22 chemical compounds with retention times ranging from 7.564 to 17.023 minutes. The identification of 22 chemical compounds through GC-MS analysis further underscores the prospect of harnessing ginger rhizome for the development of novel medications. The computational analyses showed that ginger compounds bind the 1JIJ and 2QZW with high binding affinities, which reach –9.5 kcal/mol. Ginger compounds also established promising molecular interactions with some key residues, that satisfactorily explain the in vitro results and support the pharmacokinetic and experimental findings. This study lays the groundwork for future research and pharmaceutical exploration aimed at harnessing the beneficial properties of ginger rhizome for medicinal and therapeutic purposes, particularly its antimicrobial potential.

At this time, nanoparticles used to been considered for various biomedical applications due to their particular properties[1, 2]. It is already known that one of the major advances in the relative application of nanoparticles is the recognition of the steric stabilization which can increase the particle stability in the biological environment and provide the opportunities of the application of nanoparticles in the development of drug delivery systems (DDSs) for achieving drug targeting and controlled drug release. Nano crystalline silver particles (AgNPs) have major applications in biomolecular recognition of highly sensitive, anti-microbial treatment, catalysis and manufacture sensors [3-7]. The NPs for various applications medical like image quality, medicine, tissue, magnetic resonance imaging (MRI) of targeting tissues and cells styles. This is particularly the case of AgNPs significantly encompasses the whole a wide range of industrial and medical applications. In this study, we have been synthesized incorporated omeprazole and omeprazole sulfide drugs with AgNPs and the results was investigated with TEM, FT-IR, DRS and XRD. The particle size has been seen in imaging TEM about 80 nm. Moreover either Omeprazole@AgNPs or omeprazole sulfide@AgNPs are able to excrete bacteria. In this study, the antibacterial properties of drugs with silver nanoparticles also increased.

With the increased scientific interest in green technologies, many researches have been focused on the production of polymeric composites containing naturally occurring reinforcing particles. Apart from increasing mechanical properties, these additions can have a wide range of interesting effects, such as increasing the resistance to bacterial and fungal colonization. In this work, different amounts of two different natural products, namely neem and turmeric, have been added to polyethylene to act as a natural antibacterial and antifungal product for food packaging applications. Microscopic and spectroscopic characterization showed that fractions up to 5% of these products can be dispersed into low-molecular weight polyethylene, while higher amounts could not be properly dispersed and resulted in an inhomogeneous, fragile composite. In vitro testing conducted with Escherichia coli, Staphylococcus aureus and Candida albicans showed a reduced proliferation of pathogens when compared to the polyethylene references. In particular, turmeric, resulted to be more effective against E. coli when compared to neem, while they had similar performances against S. aureus. Against C. albicans, only neem was able to show a good antifungal behavior, at high concentrations. Tensile testing showed that the addition of reinforcing particles reduces the mechanical properties of polyethylene, and, in the case of turmeric, it is further reduced by UV irradiation.

Marine microalgae are a rich reservoir of natural compounds, including bioactives. Nonetheless, these organisms remain fairly unexplored despite their potential biotechnological applications. Culture collections with diverse taxonomic groups and lifestyles are a good source to unlock this potential and discover new molecules for multiple applications such as the treatment of human pathologies or the production of aquaculture species. In the present work extracts from 33 strains (including 20 dinoflagellates, 4 diatoms and 9 strains from other 7 algal classes), cultivated under identical conditions were examined for antiviral, antibacterial, anti-inflammatory and anti-cancer activities. Among these, antiviral and anti-inflammatory activities were detected in a few strains while antibacterial tests showed positive results in most assays. In turn, most trials did not show any anti-cancer activity. Wide differences were observed between species within the same class, in particular dinoflagellates which were better represented in this study. These preliminary findings pave the way for in-depth characterization of extracts with highest signals in each test, identification of compounds responsible of the biological activities found, and a further screening of the CCVIEO culture collection.

The study of biologically active substances from natural sources shows the prospect of obtaining a new type of antimicrobial agents, highly effective against pathogenic microorganisms and non-toxic to humans. Our study reveals for the first time that Cornu aspersum mucus has the potential to act as a source of antibacterial agents against bacterial pathogens such as Bacillus cereus 1085, Propionibacterium acnes 1897, Salmonella enterica 8691, Enterococcus faecalis 3915, and Enterococcus faecium 8754. Both mucus fractions with MW<20 kDa and MW>20 kDa showed antimicrobial activity and antioxidant properties that’s why they can be turned into an alternative agent to expensive synthetic antibacterial compounds. Using de novo sequencing 16 novel peptides with potential antibacterial activity were identified by in a fraction with MW<20 kDa. The results of electrophoretic and proteomic analysis of mucus fraction with MW >20 kDa presented proteins with potential antibacterial activity highly homologous to hemocyanins, mucus protein Aspernin, lectins, L-amino acid oxidase-like protein, and mucins (mucin-5AC, mucin-5B, mucin-2 and mucin-17). Thanks to the synergistic action of the bioactive components, the mucus fraction with MW > 20 kDa in low concentrations per 8–2 µg/mL showed promising antimicrobial activity against the tested bacteria, comparable to Vancomycin and without unwanted cytotoxic effects against non-target cells. Additionally, C. aspersum mucus fractions were found to have a positive effect on eukaryotic organisms by reducing the levels of intracellular oxidative damage and increasing the antioxidant capacity of the cell. These findings could serve as a basis for the development of a potent non-cytotoxic antibacterial agent to replace conventional antibiotics and avoid the development of antibiotic resistance.

Classical antibacterial drugs were designed to target specific bacterial properties distinct from host human cells to maximize potency and selectivity. These designs were quite effective as they could be easily derivatized to bear next generation drugs. However, the rapid mutation of bacteria and their associated acquired drug resistance have led to the rise of highly pathogenic superbug bacterial strains for which treatment with first line drugs is no match. More than ever, there is a dire need for antibacterial drug design that goes beyond conventional standards. Taking inspiration by the body’s innate immune response to employ its own supply of labile copper ions in a toxic attack against pathogenic bacteria, which have a very low Cu tolerance, this review article examines the feasibility of Cu-centric strategies for antibacterial preventative and therapeutic applications. Promising results are shown for the use of Cu-containing materials in the hospital setting to minimize patient bacterial infections. Studies directed at disrupting bacterial Cu regulatory pathways elucidate new drug targets that can enable toxic increase of Cu levels and perturb bacterial dependence on iron. Likewise, Cu intracellular chelation/prochelation strategies effectively induce bacterial Cu toxicity. Cu-based small molecules and nanoparticles demonstrate the importance of the Cu ions in their mechanism and display potential synergism with classical drugs.

Background: Bacterial infections constantly have a large impact on public health, because of increased rates of resistance and reduced frequency of development of novel antibiotics. The utility of conventional antibiotics for treating bacterial infections has become increasingly challenging. The aim of the study was to assess the antibacterial effect of β -Lapachone, a novel synthetic compound. Methods: The antibacterial activity of the β -Lapachone compound was examined against laboratory strains by agar well diffusion method, minimal inhibitory concentration (MICs), and minimal bactericidal concentration (MBCs). Growth kinetics inhibition in presence of β -Lapachone on Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa (ATCC 27853) was assessed by MABA. Crystal violet blue assay was used for biofilm inhibition assays, biofilm eradication assay and for molecular modeling PyMOL was used. Results: β -Lapachone exhibited potent antimicrobial activity against laboratory strains of bacteria with MIC of 0.2 mM for S. saprophyticus and Staphylococcus aureus, and 0.04 mM for Staphylococcus epidermidis and Pseudomonas aeruginosa ATCC 27853. The inhibition of catalase enzyme was found to be the cause for its antibacterial activity. Molecular modeling predicted the binding of β -Lap at active site and heme binding site of catalase, KatA. The activity of some commercial antibiotics was enhanced in association with β -Lap. In addition, β -Lap inhibited the biofilm formation and eradicated the already formed and ultra-mature biofilms of aforesaid bacterial strains.

Many bio-applicable materials, medical devices, and prosthetics combine both polymer and metal components to benefit from their complementary properties. This goal is normally achieved by their mechanical bonding or casting only. Here, we report an alternative easy method for the chemical grafting of a polymer on the surfaces of a metal or metal alloys using alkoxy amine salt as a coupling agent. The surface morphology of the created composites was studied by various microscopy methods, and their surface area and porosity were determined by adsorption/desorption nitrogen isotherms. The surface chemical composition was also examined by various spectroscopy techniques and electrokinetic analysis. Elements distribution on the surface was determined and successful bonding of the metal/alloys on one side with the polymer on the other one was confirmed by alkoxy amine. The composites show significantly increased wettability, reliable chemical stability of the bonding, excellent bacterial anti-adhesive properties and functionality, i.e. the characteristics promising for their application in biomedical field.

Introduction: Among the many factors that may limit effective wound healing in patients with chronic ulcers, bacterial infection and poor cell recruitment are primary causes that contribute to prolonged healing. Thus, a novel strategy that aims to prevent bacterial infection within the wound, while at the same time providing structural scaffolding that promotes endogenous tissue repair, would be of great interest. Here, we developed a thermo-sensitive silver nanoparticle hydrogel composite as an antibacterial nutritional scaffold for the wound that contains all nutrients required for cell growth while preventing bacterial infection with the ability to fill up all the cavities and void areas in wounds regardless of their geometry. Methods: Silver nanoparticles (AgNPs) were synthesized by chemical reduction. After characterization, silver hydrogel nanocomposite was developed by reconstitution of collagen-based hydrogel powder in a nanoparticle suspension of varying AgNPs concentrations (200, 400, and 600 ppm). The antibacterial activity of the formulations was examined in vitro and in vivo in subcutaneous implant infected model. The wound healing efficacy of the hydrogel nanocomposite was also evaluated using a splinted wound model in rats through comparison of clinical wound measurements and histological assessments. Cytocompatibility assay and biochemical analysis of blood at the end of in vivo wound healing study were performed to evaluate the safety of formulations. Results: The synthesized nanoparticles were spherical and stable. While hydrogel alone did not show any bacterial reduction in vitro, the inhibition of bacterial growth was significant in all silver hydrogel nanocomposites compared to controls (p <0.05) and was dose-dependent, with maximum reduction observed in the 600 ppm group (4.56±0.26 LOG CFU/mL, P<0.001). All concentrations of AgNPs hydrogel composites showed significant antibacterial activity in vivo as well (P<0.0001). Treatment of splinted wounds with AgNPs hydrogel composite resulted in faster wound closure and accelerated wound re-epithelialization. The formulations were non-cytotoxic and did not differ significantly in hematological and biochemical factors from the control group in in vivo study. Conclusions: By presenting promising antibacterial and wound healing activity, silver hydrogel nanocomposite offers a safe therapeutic option that can be used as a functional scaffold for an acceleration of wound healing.

Jade waste is a normal byproduct that makes up much more than the amount of jade extracted. Therefore, recycling jade waste is worth investigating from the point of view of energy conservation. Moreover, it is an environment-friendly material, which is desirable for use in building materials. In this study, Xiuyan jade waste was repurposed as antibacterial additives for building coatings. The powder waste was activated by milling and subsequent annealing. The antibacterial properties of the treated waste were mostly related to the annealing temperatures. Based on the investigations of the phase change and the release of metal ions of a series of samples and their antibacterial activities, the antibacterial mechanism of the treated samples was explored experimentally. The most applicable sample for coatings was finally chosen by considering its pH values and its antibacterial abilities. Antibacterial testing showed that the addition of treated jade waste could enhance the bacterial inhibition rate of building coatings from 60% to 99.9%.

The prevalence of multidrug resistant bacterial diseases is a major global health risk. Multidrug resistant bacterial diseases are prevalent, and the need for novel methods of treatment is essential to the preservation of public health. Annually foodborne pathogens cause 1.35 million infections and 26,500 hospitalizations in the United States alone. Foodborne pathogens such as Salmonella spp. are a major threat to public health. Bacteriophages offer a unique method for the treatment of these multidrug resistant bacteria. We studied the infection dynamics of a potential mono-phage therapy of Salmonella typhimurium under various pathophysiological conditions. Furthermore, we determined the resistance dynamics of Salmonella typhimurium against P22 phage treatment. We also determined synergy with antibiotics such as ampicillin and kanamycin. This research helps to further define and show the versatility of bacteriophages as potential novel treatment methods.

Peri-implantitis occurs at a significant rate, which is the leading cause of implant failure. The main reason for this unwanted complication is bacterial invasion and biofilm formation. To reduce the incidence of peri-implantitis, we constructed a carboxymethyl dextran (CMD) based nanomicelles antibacterial coating on microarc-oxidized titanium (MAO-Ti) surface. After cross-linking, the drug-loaded nanomicelles were spherical with a particle size of 130nm and uniformly dispersed. Zeta potential was negative, and the absolute value was greater than 10 mV, effectively avoiding micelles aggregation. It was observed by dynamic light scattering (DLS) that the stability of nanomicelles was significantly improved after cross-linking. The hemolysis rate of micelles was less than 5%, and the overall survival rate of human umbilical vein endothelial cells was more than 90%. After being coated on MAO-Ti surface, the cumulative drug release rate of drug-loaded nanomicelles reached 86.6% after 360 hours. Fluorescence staining of immobilized bacteria showed more dead bacteria on the coating surface, and the number of live bacteria was significantly reduced. It was concluded that dextran-based nanomicelles, which showed long-term drug release properties and excellent biocompatibility, are potential drug carriers for fabricating antibacterial coating on titanium surfaces.

Cranio-maxillofacial structure is a region of particular interest in the field of regenerative medicine due to both its anatomical complexity and the numerous abnormalities affecting this area. However, this anatomical complexity is what makes possible the coexistence of different microbial ecosystems in the oral cavity and the maxillofacial region, contributing to the increased risk of bacterial infections. In this regard, different materials have been used for their application in this field. These materials can be obtained from natural and renewable feedstocks or by synthetic routes with desired mechanical properties, biocompatibility and antimicrobial activity. Hence, in this review, we have focused on bio-based polymers, which by their own nature, by chemical modifications of their structure, or by their combination with other elements, provide a useful antibacterial activity as well as the suitable conditions for cranio-maxillofacial tissue regeneration. This approach has not been reviewed previously, and we have specifically arranged the content of this article according to the resulting material and its corresponding application, reviewing guided bone regeneration membranes; bone cements; and devices and scaffolds for both soft and hard maxillofacial tissue regeneration, including hybrid scaffolds, dental implants, hydrogels and composites.

Antimicrobial peptides and structurally related peptoids offer potential for the development of new antibiotics. However, progress has been hindered by challenges presented by poor in vivo stability (peptides) or lack of selectivity (peptoids). Herein, we have developed a process to prepare novel hybrid antibacterial agents that combine both linear peptoids (increased in vivo stability compared to peptides) and a nisin fragment (lipid II targeting domain). The hybrid nisin-peptoids prepared were shown to have low µM activity (comparable to natural nisin) against methicillin-resistant Staphylococcus aureus.

A new method for the synthesis of azido-propargyloxy derivatives of 1,3,5-triazine has been developed. The antibacterial activity against E. coli bacteria of propargyloxy substituted 1,3,5-triazines - 2,4,6-trispropargyloxy-1,3,5-triazine, 2-azido-4,6-bispropargyloxy-1,3,5-triazine and 2,4-diazido-6-propargyloxy-1,3,5-triazine and their hyperbranched polymers. It has been shown that the presence of an azide group in the compound directly affects the antibacterial activity. The cytotoxicity of these compounds against the M-HeLa, FetMSC and Vero cell lines was studied. The IC50 value was determined for low molecular weight compounds. It has been shown that hyperbranched polymers without azide groups don’t exhibit pronounced cytotoxicity and can be used in biomedical applications.

Zingiber cassumunar Roxb. is a powerful medicinal plant that has been used as traditional medicine to cure respiratory problems, pain, and inflammation in China, Indonesia, Thailand and other Asian countries by using the crude extracts. The objective of this research is to identify phytochemical composition of Z. cassumunar Roxb. and to analyze antibacterial activity of crude extract, purified compounds, and their microencapsulated products of Rhizome Z. cassumunar Roxb. Identification of phytochemical composition in crude extract of rhizome Z. cassumunar Roxb. was achieved by chromatography-mass spectrophotometer. The major phytochemical composition in crude extract of Z. cassumunar Roxb. is essential oils, including terpinen4-ol (37.7%), β-pinene (20.8%), and (E)-1-(3,4-dimethoxyphenyl)but-1-ene (13.3%). Crude extract of Z. cassumunar Roxb. was purified with silica gel flash column chromatography, resulting two purified compounds. The antibacterial activity of crude extract, purified compounds, and their microencapsulated products of Rhizome Z. cassumunar Roxb. were evaluated against agricultural and foodborne pathogens by using disc agar diffusion and broth microdilution techniques. All of the samples studied (crude extracts, purified compounds, and microencapsulated of Z. cassumunar Roxb.) were effective against all the bacteria. Based on the results of the disc-diffusion assay suggested that amongst the samples studied, purified compounds (compound 1 and 2) and microencapsulated purified compounds (compound 1 and 2) exhibited more effective against all the bacteria compared to the crude extracts. Antibacterial activity of the rhizome of Z. cassumunar Roxb. was contributed mainly by the essential oils components as the active compounds. Gram-negative bacteria (X. oryzae, X. translucens, Pseudomonas spp, E. coli, and S. typhimurium) appeared to the most resistant to the crude extracts, purified compounds, and microencapsulated of Z. cassumunar Roxb. compared to the gram-positive bacteria (S. aureus, B. cereus, and L. monocytogenes). Microencapsulated of the tested samples (crude extract, purified compound 1, and purified compound 2) of the rhizome Z. cassumunar Roxb. exhibited high antibacterial activity with no significantly different with the tested samples without microencapsulation. These results suggest potential antibacterial properties of Z. cassumunar Roxb., which useful for agricultural plant health, food preservation, natural therapies, and pharmaceuticals.

Flavan-3-ols and their oligomeric forms called proanthocyanidins are polyphenolic compounds occurring in several foodstuffs and in many medicinal herbs. Their consumption is associated with numerous health benefits. Their bioactivities include antioxidant, anti-inflammatory, cytoprotective, as well as antimicrobial. The latter property is important in prevention and treatment of periodontal diseases. Periodontitis is a multifactorial polymicrobial infection characterized by a destructive inflammatory process affecting the periodontium. Using non-toxic and efficient natural products such as flavanol derivatives can significantly contribute to alleviating of periodontitis symptoms and prevent the disease progress. In this paper, we systematically review the state-of-the art in antibacterial effects of these compounds from the viewpoint of gum health. There is a significant evidence supporting an importance of antibacterial action exerted by proanthocyanidins from edible fruits, tea and medicinal herbs in inhibition of periodontitis-causing pathogens.

Keywords: Antibacterial activity, Antioxidant activity, Bioactive compounds, Elementary analysis, Nutritional and phytochemical composition, Seaweed.

Hydrogel wound dressings hold great potential in eliminating bacteria and accelerating the healing process. However, it remains a challenge to fabricate hydrogel wound dressings that simultaneously exhibit excellent mechanical and photothermal antibacterial properties. Here we report the development of polydopamine-functionalized graphene oxide/calcium alginate/Polypyrrole cotton fabric-reinforced hydrogels (abbreviated as rGO@PDA/CA/PPy FHs) for tackling bacterial infections. The mechanical properties of hydrogels were greatly enhanced by cotton fabric reinforcement and an interpenetrating structure, while excellent broad-spectrum photothermal antibacterial properties based on the photothermal effect were obtained by incorporating PPy and rGO@PDA. Results indicated that rGO@PDA/CA/PPy FHs exhibited superior tensile strength in both the warp (289±62.1N) and weft directions (142±23.0N) similar to cotton fabric. By incorporating PPy and rGO@PDA, the swelling ratio was significantly decreased from 673.5% to 236.6%, while photothermal conversion performance was significantly enhanced with a temperature elevated to 45.0 ℃. Due to the synergistic photothermal properties of rGO@PDA and PPy, rGO@PDA/CA/PPy FHs exhibited excellent bacteria-eliminating efficiency for S. aureus (0.57%) and E. coli (3.58%) after exposure to NIR for 20 min. We believe that the design of fabric-reinforced hydrogels could serve as a guideline for developing hydrogel wound dressings with improved mechanical properties and broad-spectrum photothermal antibacterial properties for infected wound treatment.

This study aimed to elucidate the antibacterial efficacy and unique chemical compositions generated from plasma-activated water (PAW) when utilized a novel vaginal cleansing device. We conducted an analysis of antibacterial activity against probiotics and several chemical compositions including ions under various operational parameters of PAW, including electrical power (12 and 24 V), treatment duration (1, 10, and 20 min), and stay duration (immediate, 30 and 60 min). Our findings revealed that as treatment duration increased, hypochlorous acid (HOCl), Ca2+, and Mg2+ concentrations increased and Cl−concentrations decreased. Higher electrical power and longer treatment duration resulted in increased HOCl levels, which acts to prevent the growth of general microorganisms. Notably, PAW exhibited no antibacterial effects against a type of probiotic, Lactobacillus reuteri that produces lactic acid for vaginal health. This result demonstrated the ability of the vaginal cleaning device to generate ions, primarily HOCl and some cations (Ca2+ and Mg2+), thereby providing vaginal mucosa protecting and cleansing effects with the vaginal environment.

Abstract: Given the increasing resistance of some bacterial strains to many common antibiotics used in the local market, the current study aimed to produce nanoscale particles capable of combating pathogenic bacteria that have developed resistance to current antibiotics. In this research, an ex-perimental study was conducted to produce nanoscale particles using the single-celled blue-green algae Synechococcus sp., which was isolated from a local environment in the Arab Republic of Egypt, specifically from a soil sample in Beni-Suef City. The aim of the study was to generate silver NPs employing different biological approaches, encompassing the direct strain powder technique, ethanol extract pellet technique, and ethanol extract technique. These synthesized nanoparticles displayed different shapes, including cubic, spherical, pellet-like, and rod-shaped particles. They were characterized by bio-functional groups containing Ag+ ions, which were detected using FT-IR, Zeta sizer, and Zeta potential measurements. High-resolution SEM imaging unveiled the mor-phological features of Silver NPs with biologically formed protective layers, spanning sizes from 20 to 430 nm for individual particles. The study evaluated the antibacterial efficiency against both G+ve and G-ve bacteria. The ethanolic extract technique exhibited the largest inhibition zone (24 mm) against G+ve bacteria, particularly Staphy. aureus. Furthermore, it was observed that the larger particles produced using the powder and pellet techniques were less effective antibacterial agents. In conclusion, this investigation emphasizes the potential of cyanobacteria-based synthesis of silver nanoparticles as a promising approach for producing innovative antimicrobial agents.

The increased emergence of multidrug-resistant Helicobacter pylori influences the prevention of stomach cancer. Zingiber officinale is a plant usually used in folk medicine to treat a variety of diseases involving infections, nausea, vomiting, peptic ulcer, dyspepsia, and inflammation. This study was conducted to evaluate the ability of Z. officinale extract to combat resistant H. pylori. The disc diffusion, microdilution, and microplate assays were performed to evaluate the susceptibility to antibiotics, and the antibacterial and antibiofilm activities of the Z. officinale extracts. Using the checkerboard method, the combined effects of the gentamicin and Z. officinale extract were investigated. In addition, anti-inflammatory activity and GC-MS analysis were determined by the modified protocol. According to the findings, H. pylori isolates exhibited resistance rates of 56.33, 50.0, and 45.85 for metronidazole, gentamicin, and tetracycline, respectively. The methanolic extract of Z. officinale had the strongest effectiveness against resistant H. pylori isolates with MIC of 20.0 to 50.0 µg/ml against both H. pylori isolates and the stranded strain NCTC 11637. Z. officinale extract suppress the biofilm formed by H. pylori isolates with a percentage of 92.96% at 50.0µg/ml, compared with 97.19% for gentamicin at the same concentration. According to FICI values, combination of methanolic Z. officinale extract to gentamicin increases bacterial sensitivity to such drugs. Moreover, the Z. officinale extract exhibits strong anti-inflammatory activity. The GC-MS analysis of Z. officinale extract exhibits 17 different chemical compounds. Conclusions: The Z. officinale extract contain the anti-inflammatory compound gingerol as the main constituent which inhibits the growth of H. pylori and its biofilm, are a promising natural therapeutic alternative or enhance antibiotics activity

Natural products are an important source of antibacterial agents. Canthin-6-one alkaloids have displayed potential antibacterial activity based on our previous work. In order to improve the activity, twenty-two new 3-N-benzylated 10-methoxy canthin-6-ones were designed and synthesized through quaternization reaction. The in vitro antibacterial activity against three bacteria was evaluated by double dilution method. Four compounds (6f, 6i, 6p and 6t) displayed 2-fold superiority (minimum inhibitory concentration (MIC) = 3.91 µg/mL) against agricultural pathogenic bacteria R. solanacearum and P. syringae than agrochemical propineb. Moreover, the structure–activity relationships (SARs) were also carefully summarized in order to guide the development of antibacterial canthin-6-one agents.

We report the production of metal oxide (TiFe₂O₄, ZnFe₂O₄) nanoparticles by pulsed laser ablation technique in liquid environment. We used nano second Nd: YAG laser systems working at 532 nm and 1064 nm of wavelength, the energy of the laser beam was kept constant at 80 mJ. Absorbance spectra, surface plasmon resonance, optical band-gap and nanoparticle morphology were investigated using ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Changing the wavelength of the laser for growth, nanoparticles shown shift between the absorbance and surface plasmon resonance peaks in their UV-Vis spectra, this implies that the optical properties of the colloid nanoparticles depends on laser parameters, this was confirmed with the variation of the band gap energy. Furthermore, red shift for the absorbance peak was observed for samples as-growth at 532 nm around the 150 nm as function of time preparation. Whereas, for the samples as-growth at 1064 nm there is no shift in the absorbance spectra, this can be due to agglomeration and formation of larger particles. The characterization results shown appropriate plasmonic photo-catalysts properties of the particles, hence the photo activation of the nanoparticles was examined on antibacterial effect using colonies of Staphylococcus Aureus and Escherichia coli.

This review focuses on Cu/TiO2 sequentially and Cu-TiO2 co-sputtered catalytic/photocatalytic surfaces leading to bacterial inactivation discussing their stability, synthesis, adhesion and antibacterial kinetics. The intervention of TiO2, Cu and the synergic effect of Cu and TiO2 on films prepared by a colloidal approach and other techniques is also reviewed leading to bacterial inactivation. Processes in aerobic media and anaerobic media leading to bacterial loss of viability on multidrug resistant (MDR) pathogens, Gram-negative (-) and Gram-positive(+) bacteria are described. Insight is provided for the interfacial charge transfer mechanism under solar irradiation occurring between TiO2 and Cu. surface properties of 2D TiO2/Cu and TiO2-Cu films are correlated with the bacterial inactivation kinetics observed in the dark and under light. The intervention of these antibacterial sputtered surfaces in health-care facilities leading to MRSA-isolates is described in the dark and under the actinic light. The synergic intervention of the Cu and TiO2 films leading to bacterial inactivation prepared by direct current magnetron sputtering (DCMS), pulsed direct current magnetron sputtering (DCMSP) and highly ionized pulse plasma magnetron sputtering (HIPIMS) is reported in a detailed way.

The emergence of multidrug-resistant strains of many pathogens is a serious threat and makes chemotherapy more difficult. The main objective of this study was to evaluate the antibacterial activity of Senna singueana and Cyphostemma junceum plant extracts against Staphylococcus aureus and Pseudomonas aeruginosa. The crude extracts of the selected medicinal plants were prepared and subjected to phytochemical screening using standard methods. Antibacterial activity was determined using the disc diffusion method. Therefore, the highest (15.41%) and lowest (0.91%) percentage yields were obtained from ethanol stem bark extracts and chloroform root extracts of Senna singueana, respectively. The maximum (14±1.0 mm) and minimum (7.5±0.5 mm) zones of inhibition were obtained from chloroform and distilled water leaf extracts of Senna singueana against Pseudomonas aeruginosa, respectively. In addition, the highest (13.5±1.0) zone of inhibition was obtained from Cyphostemma junceun root extract at 125 µg/ml. No inhibition zones were recorded in the root extract of Cyphostemma junceun at 500 µg/ml. More rich secondary metabolites, such as flavonoids, tennins, phenols, glycosides, terpenoids and sapnoids, were screened from distilled water leaf extracts, while flavonoids, tennis, phenols, glycosides, terpenoids, sapnoids and coumarins were screened in ethanol root extracts of Cyphostemma junceum. The leaves, stem bark and root of Senna singueana as well as the root of Cyphostemma junceun have strong antibacterial activity against both bacterial species. Thus, the two plant extracts could be used for healing and killing bacterial agents that can be potential sources for drug development.

This research focuses on exploring the bioactive and antibacterial properties of extracts from the flowers and bark of four Magnolia species (Magnolia champaca, Magnolia denudata, Magnolia grandiflora, and Magnolia officinalis) for possible cosmetic applications. We used ethanol to extract compounds from these plants and conducted various tests including spectrophotometry, HPLC, GC-MS, and microbiological analyses. The extracts, particularly rich in polyphenols (55.18 mg GAE/g), displayed significant antioxidant capabilities, with IC 50 values ranging between 9.99 mg/mL and 23.23 mg/mL. We quantified different compounds: phenolic acids (6.259 to 27.883 mg/g dry weight), aglycone flavonoids (61.224 to 135.788 mg/g dw), glycosidic flavonoids (17.265 to 57.961 mg/g dw), and lignans (150.071 to 374.902 mg/g dw). We identified 76 volatile compounds, predominantly oxygenated monoterpenes and sesquiterpene hydrocarbons, which contribute to the antibacterial effectiveness of the extracts. These extracts showed greater antibacterial activity against Gram-negative bacteria than Gram-positive bacteria. The diverse chemical compounds and their demonstrated activities suggest these extracts could be valuable in cosmetic, pharmaceutical, or food industries.

Background: The use of nitinol (NiTi) archwires in orthodontic treatment has expanded significantly due to unique mechanical properties. The greatest barrier to safe orthodontic treatment is chemically or microbiologically induced corrosion, resulting in Ni2+ release. The aim of this investigation was to enhance corrosion resistance and introduction antibacterial properties to NiTi archwire by coating them with TiN-Cu. Methods: NiTi archwires were coated with TiN-Cu using cathodic arc evaporation and direct current magnetron sputtering. The morphology of the sample was analyzed by FESEM and the chemical composition was assessed using EDS, XRD and FTIR. Inductively coupled plasma-optical emission spectrometry was used to estimate the ion release. Biocompatibility of samples was investigated using MTT test. Antibacterial activity was analyzed against Streptococcus mutans and Streptococcus mitis. Results: Physico-chemical characterization revealed well-designed coatings with the presence of TiN phase with incorporated Cu2+. TiN-Cu coated archwires showed statistically lower Ni2+ release (p<0.05). Relative cell viability was the highest regarding 28-day eluates of TiN-Cu coated archwires (p<0.05). The most remarkable decrease in Streptococcus mitis concentrations was observed in case of TiN-Cu coated archwires (p<0.05). Conclusion: Taking into account biocompatibility and antibacterial tests, TiN-Cu coated archwires may be considered as a good candidate further clinical investigations.

Pectin extracted via hydrodynamic cavitation in water only from waste lemon peel and further isolated via freeze drying displays significant antibacterial activity against Staphylococcus aureus, a Gram positive pathogen which easily contaminates food. The antibacterial effect of the new IntegroPectin is largely superior to that of commercial citrus pectin, opening the way to advanced applications of a new bioproduct now obtainable in large amounts and at low cost from citrus juice industry’s waste.

Background: We investigated the effect of bioactive glass and zinc oxide nanoparticles on enamel remineralization, as well as their antibacterial effect on cariogenic bacteria. Methods: Fluoride gel (F), bioactive glass microparticles (µB), bioactive glass nanoparticles (nB), zinc oxide nanoparticles (Z), and a mixed suspension of nB and Z (nBZ) were prepared and subjected to the following tests: morphological evaluation by scanning and transmission electron microscopy, measurement of specific surface area, zeta potential measurement, crystal structure analysis by X-ray diffraction, and acid buffering capacity test. Further, we performed a remineralization cycle test of 28 days and a nanoindentation testing was carried out during the immersion period and then the enamel surfaces were examined using scanning electron microscopy. Additionally, the antibacterial effects of the sample suspensions were evaluated by measuring their minimum bactericidal concentrations against various cariogenic bacteria. Results: Our results revealed that nB had a near-circular shape with an amorphous structure, a considerably large specific surface area due to nanoparticulation. Additionally, nB possessed a rapid acid buffering capacity, which was comparable to that of μB. In the remineralization test, faster recovery of mechanical properties was observed on the enamel surface immersed in samples containing bioactive glass nanoparticles (nB and nBZ). After remineralization, demineralized enamel immersed in any of the samples showed a rough and porous surface structure covered with mineralized structures. Furthermore, nBZ exhibited a broad antibacterial spectrum. Conclusions: These results demonstrated that bioactive glass and zinc oxide nanoparticles have superior demineralization-suppressing and remineralization-promoting effects.

Croton grewioides Baill., a species native to the Caatinga, popularly known as canela de cunhã, is used in traditional medicine to treat gastrointestinal diseases such as diarrhea, gastritis and stomach ulcers. This study aimed to identify the chemical composition of the essential oil of C. grewioides (OECG) and evaluate its antibacterial and antibiotic-modulating activities against both standard and multidrug-resistant bacteria. To analyze the compounds, present in the oil, gas chromatography coupled with mass spectrometry (GC/MS) and gas chromatography with flame ionization detector (GC/FID) techniques were used. In the bacteriological tests, the Minimum Inhibitory Concentration (MIC) was obtained using the broth microdilution technique. The modulating effect of the essential oil was determined by calculating the subinhibitory concentration followed by serial microdilution of the antibiotics. The MIC reduction factor (FRC) was calculated and its data expressed as a percentage. Analysis of the chemical composition identified the presence of the major compound estragole with a relative abundance of 50.34%. The MIC values obtained demonstrated efficacy in K. pneumoniae isolated from urine with MIC values of 512 µg/mL. OECG potentiated the effects of all antibiotics tested on S. aureus ATCC 29213, K. pneumoniae Carbapnemase, E. coli ATCC 25922 and S. aureus ATCC 29213 strains with their FRC of 97.65 %, 99.80 %, 99.85 % and 99.88 %, respectively. Thus, the essential oil of C. growioides presents synergistic effects when combined with the tested antibiotics, in addition to acting in the fight against bacterial resistance to antibiotics.

Elemental sulfur, commonly known for its wide range of biological activity, has a long history of being used to protect all garden and vegetable crops from a range of pests and diseases, including powdery mildew, ascochyta blight, clubroot, plant mites, oidium, anthracnose, and scab. In the present study, a quick and environmentally friendly approach has been developed for the synthesis of sulfur nanoparticles with antibacterial activity. Sulfur nanoparticles (SNPs) were prepared by modifying the surface of elemental sulfur using various polyelectrolyte-surfactant mixtures (PSM) including NaCMC-SDBS and PHMG-CTAB. The SNPs were characterized by UV–visible spectrophotometry, X-ray diffraction (XRD), and thermogravimetric analysis (TG/DSC), scanning electron microscopy (SEM), with the SNPs showing an almost spherical shape with an average size in the range of 150-200 nm. The antibacterial activity of the sulfur nanoparticles was tested using against gram-positive S. aureus and E. faecium and gram-negative E. coli and P. aeruginosa bacteria. From this, it could be seen that SNPs exhibited significant antimicrobial activity against gram-positive bacteria, i.e., S. aureus and E. faecium. The in vitro cytotoxicity of the SNPs-1 and SNPs-2 studied to normal (MeT-5A) and tumorous (MCF-7) human cell lines was assessed in the concentration range from 500 μg/ml to 0.12 mg/ml, from which it was determined as being non-cytotoxic. The received products can be considered for potential application in agriculture and medicine.

Aim: Nepal’s medicinal plants are culturally important and have diverse benefits. Senna alata belongs to the family Leguminosae and is a valuable plant utilized for medicinal and ornamental purposes. The aim of the research was to extract Senna alata leaves by successive maceration with various solvents. Methods: In this study, various methods were utilized to evaluate phytochemistry, overall phenolic and flavonoid content, in-vitro antioxidant, anti-inflammatory, cytotoxicity assay, anti-thrombolytic activity, and antibacterial activities. Results: The extractive values of Senna alata were determined as 1.58%, 0.78%, and 5.92% in hexane, ethyl acetate, and methanol, respectively. GC-MS analysis revealed major compounds such as 3-Methylmannoside, Neophytadiene, Campesterol, and Vitamin E in the leaf extract. Qualitative phytochemical screening verified the tannin content, carbohydrates, flavonoids, cardiac glycosides, glycosides, and saponins in the methanol extract. The total phenolic and flavonoid values were 46.36±4.5 mg GAE/gm and 480.4±3.055 QE/gm of dried extract, respectively. The extract exhibited significant antioxidant and anti-inflammatory activities, with IC50 values of 29.81 and 9.93, respectively. Furthermore, it demonstrated cytotoxic activity with an LC50 value of 767.85 in the brine shrimp bioassay. In terms of thrombolytic activity, the extract showed clot lysis percentages of 7.89% and 10.13% at concentrations of 10 mg/ml and 25 mg/ml, respectively. Conclusion: In conclusion, the methanolic extract of Senna alata leaves displayed therapeutic potential, including antioxidant, anti-inflammatory, cytotoxic, thrombolytic, and antibacterial effects. The existence of several chemicals via GC-MS analysis also verified plant's potential for therapeutic use.

The development of magnesium calcium phosphate bone cements (MCPCs) have garnered big attention. MCPCs are bioactive and biodegradable and have appropriate mechanical and antimicrobial properties for use in reconstructive surgery. In this study, the cement powders based on a (Ca + Mg)/P = 2 system doped with Zn2+ at 0.5 and 1.0 wt.% were obtained and investigated. After the mixing with a cement liquid, structural and phase composition, morphology, chemical structure, setting time, compressive strength, degradation behavior, solubility, antibacterial activities, and in vitro behaviour of the cement materials were examined. A high compressive strength of 48 ± 5 MPa (mean ± SD) was achieved for the cement made from Zn2+ 1.0-wt.%-substituted powders. The Zn2+ introduction led to antibacterial activity against Staphylococcus aureus and Escherichia coli strains, with an inhibition zone diameter up to 8 mm. Biological assays confirmed that the developed cements are cytocompatible and promising as a potential bone substitute in reconstructive surgery.

Products derived from Cannabis sativa have gained increased interest and popularity. As these products become common amongst the public, the heath and potential therapeutic values associated with hemp have become a premier focus of research. While the psychoactive and medicinal properties of Cannabis products have been extensively highlighted in literature, the antibacterial properties of CBD have not been explored in depth. This research serves to examine the antibacterial potential of CBD against Salmonella newington and Salmonella typhimurium. In this study we observed bacterial response to CBD exposure through biological assays, bacterial kinetics, and fluorescence microscopy. Additionally, comparative studies between CBD and ampicillin were conducted against Salmonella typhimurium and Salmonella newington to determine comparative efficacy. Furthermore, we observed potential resistance development of our Salmonella spp. against CBD treatment.

The current research work illustrates an economic and rapid approach towards biogenic synthesis of silver nanoparticles using aqueous Punica granatum leaves extract (PGL-AgNPs). The optimization of major parameters involved in the biosynthesis process was done using Box-Behnken Design (BBD). The effects of different independent variables (parameters) namely concentration of AgNO3, temperature and ratio of extract to AgNO3on response viz. particle size and polydispersity index were analyzed. As a result of experiment designing, 17 reactions were generated which were further validated experimentally. The statistical and mathematical approaches were employed on these reactions in order to interpret the relationship between the factors and responses. The biosynthesized nanoparticles were initially characterized by UV-vis spectrophotometry followed by physicochemical analysis for determination of particle size, polydispersity index and zeta potential via dynamic light scattering (DLS), SEM and EDX studies. Moreover, the determination of functional group present in the leaves extract and PGL-AgNPs was done by FTIR. Antibacterial and antibiofilm efficacies of PGL-AgNPs against Gram-positive and Gram-negative bacteria were further determined. The physicochemical studies suggested that PGL-AgNPs were round in shape and of ~ 37.5 nm in size with uniform distribution. Our studies suggested that PGL-AgNPs exhibit potent antibacterial, and antibiofilm properties.

In this work, a xylan-based antimicrobial additive agent was prepared and aimed for uses in paper products against Escherichia coli bacteria. The derived Cationic-Xylan-grafted-PHGH (CX-g-PHGH) was successfully synthesized by graft copolymerization of cationic-xylan with guanidine polymer (PHGH) using ceric ammonium nitrate as initiator. The obtained CX-g-PHGH had maximum PHGH grafting ratio of 18.45% and efficiency of 58.45%, and showed good viscosity and thermal stability. Furthermore, the paper samples prepared in this work were reinforced obviously with the addition of CX-g-PHGH by improved mechanical properties. Compared to the reference paper without any of the xylan-derivatives, the index of tensile, tear, burst and folding endurance of the paper had increases up to 20.07%, 25.31%, 30.20% and 77.78%, respectively. Moreover, the prepared CX-g-PHGH paper exhibited an efficient antimicrobial activity against E. coli bacterial, by which a lot of applications based on the new xylan-derived additive agent obtained in this work could be found, especially in field of antimicrobial paper products against E. Coli bacteria from contaminated food.

The study explores antibacterial, antiinflammatory and cytoprotective capacity of Pelargonium sidoides DC root extract (PSRE) and proanthocyanidin fraction from PSRE (PACN) under conditions characteristic for periodontal disease. Following previous finding that PACN exerts stronger suppression of Porphyromonas gingivalis compared to the effect on commensal Streptococcus salivarius, the current work continues antibacterial investigation on Staphylococcus aureus, Staphylococcus epidermidis, Aggregatibacter actinomycetemcomitans and Escherichia coli. PSRE and PACN are also studied for their ability to prevent gingival fibroblast cell death in the presence of bacteria or bacterial lipopolysaccharide (LPS), to block LPS- or LPS+IFNγ-induced release of inflammatory mediators, gene expression and surface antigen presentation. Both PSRE and PACN were more efficient in suppressing Staphylococcus and Aggregatibacter compared to Escherichia, prevented A. actinomycetemcomitans- and LPS induced death of fibroblasts, decreased LPS-induced release of interleukin 8 and prostaglandin E2 from fibroblasts and IL-6 from leukocytes, blocked expression of IL-1β, iNOS, and surface presentation of CD80 and CD86 in LPS+IFNγ-treated macrophages, and IL-1β and COX-2 expression in LPS-treated leukocytes. None of the investigated substances affected either the level of secretion or expression of TNFα. In conclusion, PSRE, and especially PACN, possess strong antibacterial, antiinflammatory and gingival tissue protecting properties under periodontitis mimicking conditions and are suggestable candidates for treatment of the disease.

Many wounds are unresponsive to current available treatment techniques and therefore there is an immense need to explore suitable materials including biomaterials, which are being considered as the crucial factor to accelerate the healing cascade. In this study, we fabricated polyhydroxyalkanoate based antibacterial mats via electrospun technique. One-pot green synthesized graphene decorated silver nanoparticles (GAg) were incorporated into the fibres of poly-3 hydroxybutarate-co-12 mol% hydroxyhexanoate (P3HB-co-12mol% HHx), a co-polymer of polyhydroxyalkanoate (PHA) family which is highly biocompatible, biodegradable and flexible in nature. The synthesised PHA/GAg biomaterial was characterized by field emission scanning electron microscopy (FESEM), elemental mapping, thermogravimetric analysis (TGA), UV-visible spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FTIR). In-vitro antibacterial analysis were performed to investigate the efficacy of PHA/GAg against gram positive Staphylococcus aureus (S.aureus) strain 12600 ATCC and gram negative Escherichia coli (E.coli) strain 8739 ATCC. The results indicated that the PHA/GAg demonstrated significant reduction of Staphylococcus aureus (S.aureus strain 12600 ATCC) and Escherichia coli (E.coli strain 8739 ATCC) as compared to bare PHA or PHA-rGO in 2 hours of time. The P value (P< 0.05) was obtained by using 2 sample T-test distribution.

Emergence of more virulent forms of human pathogenic bacteria with multi drug resistance is a serious global issue and requires alternative control strategies. The current study was focused to investigate the antibacterial and antibiofilm potential of ferulic acid grafted chitosan (CFA) against Listeria monocytogenes (LM), Pseudomonas aeruginosa (PA), and Staphylococcus aureus (SA). The present result showed that CFA at 64 µg/mL concentration exhibit bactericidal action against LM and SA (>4 log reduction) and bacteriostatic action against PA (<2 log CFU) within 24 h of incubation. Further studies based on propidium iodide uptake assay, measurement of material released from the cell, and electron microscopic analysis revealed that the bactericidal action of CFA was due to the altered membrane integrity and permeability. CFA dose-dependently inhibited biofilm formation (52-89% range), its metabolic activity (30.8-75.1% range) and eradicated mature biofilms, and reduced viability (71-82% range) of the test bacteria. Also, the swarming motility of LM was differentially affected at sub-MIC concentration of CFA. In the present study, the ability of CFA to kill and alter the virulence production in human pathogenic bacteria will insight a new scope for the application of these biomaterials in healthcare to effectively treat bacterial infections.

Nitric oxide (NO) is involved in physiological processes, including vasodilatation, wound healing and antibacterial activities. As NO is a free radical, designing drugs to generate therapeutic amounts of NO in controlled spatial and time manners is still a challenge. In this study, the NO donor S-nitrosoglutathione (GSNO) was incorporated into the thermoresponsive Pluronic F-127 (PL) - chitosan (CS) hydrogel, with an easy and economically feasible methodology. CS is a polysaccharide with known antimicrobial properties. Scanning electron microscopy, rheology and differential scanning calorimetry techniques were used for hydrogel characterization. The results demonstrated that the hydrogel has a smooth surface, thermoresponsive behavior and good mechanical stability. The kinetics of NO release and GSNO diffusion from GSNO-containing PL/CS hydrogel demonstrated a sustained NO/GSNO release, in concentrations suitable for biomedical applications. The GSNO-PL/CS hydrogel demonstrated a concentration-dependent toxicity to Vero cells, and antimicrobial activity to Pseudomonas aeruginosa (minimum inhibitory concentration and minimum bactericidal concentration values of 0.5 µg·mL^-1 of hydrogel, which corresponds to 1 mmol·L^-1 of GSNO). Interestingly, the concentration range in which the NO-releasing hydrogel demonstrated an antibacterial effect was not found to be toxic to the Vero mammalian cell. Thus, the GSNO-PL/CS hydrogel is a suitable biomaterial for topical NO delivery applications.

Green synthesis using plant extracts has emerged as an eco-friendly, clean, and viable strategy alternative to chemical and physical approaches. The leaf, stem, and root extracts of Lannea discolor was utilized as a reducing and stabilizing agent in the synthesis of gold (AuNPs) and copper (CuNPs) nanoparticles. The formation of AuNPs and CuNPs confirmed by their color change, was characterised by UV–Vis Spectroscopy (UV- Vis), Scanning electron microscopy analysis and energy dispersive x-ray (SEM-EDX), Transmission Electron Microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR), coupled with minimum concentration inhibitory (MIC) antibacterial assays. AuNFs, NPs and CuNPs peaked at wavelengths in the ranges of 316, 544 and 564 nm respectively. TEM showed unexpected nanoflowers (30 – 97 nm) in the leaf extracts and spherical NPs (10 -33 nm; 9.3 – 37.5) from stem and root extracts, while spherical CuNPs (20 – 104 nm), were observed from all the extracts. EDX was able to confirm the presence of metal salts and FTIR revealed stable capping agents. AuNPs and NFs from L. discolor extracts showed appreciable antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus subtilis, when compared to the plant extracts, while none was observed from the CuNPs. These AuNPs and CuNPs are particularly appealing in a variety of applications in the biomedical as well as conductivity manufacturing, due to their shapes and sizes and economical and environmentally friendly production.

The biological synthesis of nanoparticles has been emerging as an environmentally benign and eco-friendly method owing to its cost-effectiveness and high efficiency. Recently, the biological synthesis of semiconductor and metal-doped semiconductor nanoparticles with enhanced photocatalytic degradation efficiency and anticancer and antibacterial properties have gained tremendous attention. In pursuit of this purpose, for the first time, we biosynthesized zinc oxide (ZnO) and silver/ZnO nanocomposites (NCs) as semiconductor and metal-doped semiconductor nanoparticles, respectively, using the cell-free filtrate (CFF) of Lysinibacillus sphaericus bacterium. The biosynthesized ZnO and Ag/ZnO were characterized by various techniques such as ultraviolet-visible spectroscopy, X-ray diffraction, Fourier-transform Infrared spectroscopy, Field-emission scanning electron microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The photocatalytic degradation potential of these semiconductor/metal-semiconductor nanoparticles was evaluated against the degradation of azo dye methylene blue (MB) under simulated solar irradiation. Ag/ZnO showed 90.7 ± 0.91% photocatalytic degradation of MB, compared to 50.7 ± 0.53% by ZnO in 120 min. The cytotoxicity of ZnO and Ag/ZnO on human cervical HeLa cancer cells was determined using an MTT assay. Both nanomaterials exhibited cytotoxicity in a concentration-dependent and time-dependent manner on HeLa cells. The antibacterial activity was also determined against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus). Compared to ZnO, Ag/ZnO NPs showed higher antibacterial activity. Hence, the biosynthesis of semiconductor nanoparticles could be a promising strategy for developing hybrid metal/semiconductor nanomaterials for different biomedical and environmental applications.

Antimicrobial resistance is on the rise, and there aren't enough new treatments to combat it. This might send the modern world back to the pre-antibiotic age. The molecular hybrids of pyrazolo[3,4-b]pyridine and triazole have been designed, synthesized, and analyzed for their drug-like molecule nature and in vitro analyses for their inhibition potentials against S. Aureus and K. Pneumoniae. The compounds CY-R2-25 and CY-R2-28 have been identified as the high potential molecules in this series based on in vitro experiments. CY-R2-25 has zone of inhibition values of 15 0.82 and 14 0.7, whilst CY-R2-28 has the zone of inhibition values of 18 0.95 and 16 0.82 against S. Aureus and K. Pneumoniae, respectively. MIC and MIB values for CY-R2-25 and CY-R2-28 against S. Aureus and K. Pneumoniae are 0.25 and 0.5, respectively.

This work emphasizes to use silver decorative method to enhance the antibacterial activity of TiO₂ and ZnO nanoparticles. These silver decorated nanoparticles (hybrid nanoparticles) were synthesized by using sodium borohydride as a reducing agent, with the weight ratio of Ag precursors: oxide nanoparticles = 1: 30. The morphology and optical property of these hybrid nanoparticles were investigated using transmission electron microscopy (TEM) and UV–vis spectroscopy. The agar-well diffusion method was used to evaluate their antibacterial activity against both Staphylococcus aureus and Escherichia coli bacteria, with or without light irradiation. The TEM images indicated clearly that silver nanoparticles (AgNPs, 5-10 nm) were well deposited on the surface of nano-TiO₂ particles (30-60 nm). Besides, smaller AgNPs (< 2 nm) were dispersed on the surface of nano-ZnO particles (20-50 nm). UV-vis spectra confirmed that the hybridization of Ag and oxide nanoparticles led to shift the absorption edge of oxide nanoparticles to the lower energy region (visible region). The antibacterial tests indicated that both oxide pure nanoparticles did not exhibit inhibitory against bacteria, with or without light irradiation. However, the presence of AgNPs in their hybrids, even at low content (< 40 mg/mL) leads to a good antibacterial activity and the higher inhibition zones under light irradiation as compared to that in dark was observed.

Copper oxide nanoparticles (CuONPs) were synthesized using an eco-friendly method and their antimicrobial and biocompatibility properties were determined. The supernatant and extract of the fungus Ganoderma sessile yielded small, quasi-spherical NPs with an average size of 4.5 ± 1.9 nm and 5.2 ± 2.1 nm, respectively. CuONPs showed antimicrobial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Minimum inhibitory concentration (MIC) for E. coli and S. aureus was 15.9 µg/mL for nanoparticles (NPs) using the supernatant (CuONPs-S) and 16.5 µg/ml for NPs using the extract (CuONPs-E). Lower concentrations were required for P. aeruginosa inhibition. Ultrastructural analysis revealed the presence of the small CuONPs all through the bacterial cells. Finally, the toxicity of CuONPs was analyzed in three mammalian cell lines: hepatocytes (AML-12), macrophages (RAW 264.7) and kidney (MDCK). Low concentrations (<15 µg/ml) of CuONPs-E were non-toxic to kidney cells and macrophages, and the hepatocytes were the most susceptible to CuONPs-S. The results obtained suggest that the CuONPs synthesized using the extract of the fungus G. sessile, could be further evaluated for the treatment of superficial infectious diseases.

Antibiotics have become a widely used drug classes worldwide. Its indiscriminate use in the clini-cal-hospital environment ended up causing antibiotic-resistance genes. Pharmaceutical technology is an essential ally for new formulation development in the antibacterial field. Cyclodextrins (CDs) are ap-proaches that can potentially improve the effectiveness of antibacterial drugs. Thus, this study aimed to review experimental models using CDs as inclusion complexes to improve antibacterial drugs’ physi-cochemical characteristics and biological activities. The review was carried out using the three online journals database PubMed, Scopus, and Embase, limited to Medical Subjects Headings Index. The search protocol was registered in the Open Science Framework database. The following terms and their com-binations were used: cyclodextrins and antibacterial agents in title or abstract, and a total of 1580 studies were identified in a period up to October 2022. Finally, 27 articles were selected for discussion in this review. The biological results reveal that the antibacterial effect of the compounds, complexed with CDs, was extensively improved when compared to the free drugs. CDs can improve the therapeutic effects of antibiotics, already existing on the market, natural products, and synthetic molecules. Therefore, these inclusion complexes using CDs increase the new pharmaceutical products development for clinical ap-plication.

Ticks are key vectors of some important diseases of humans and animals. Although they are carriers of disease agents, the viability and development of ticks are not harmed by the infectious agents due to their innate immunity. Antimicrobial peptides directly protect hosts against pathogenic agents such as viruses, bacteria, and parasites. Among the identified and characterized antimicrobial peptides, defensins have been considerably well studied. Defensins, which contain intramolecular disulfide bridges between cysteine residues, are commonly found among fungi, plants, invertebrates, and vertebrates. The sequence of the tick hemolymph defensin (HEdefensin) gene from the hard tick Haemaphysalis longicornis was analyzed after identification and cloning from a cDNA library. HEdefensin has a predicted molecular mass of 8.15 kDa and a theoretical isoelectric point of 9.48. Six cysteine residues were also identified in the amino acids. The synthetic HEdefensin peptide only showed antibacterial activity against Gram-positive bacteria such as Micrococcus luteus. A fluorescence propidium iodide exclusion assay also showed that HEdefensin increased the membrane permeability of M. luteus. Additionally, an indirect fluorescent antibody test showed that HEdefensin binds to M. luteus. These results suggested that HEdefensin strongly affects the innate immunity of ticks against Gram-positive bacteria.

Phenothiazine derivatives are widely studied in various fields such as biology, chemistry, and medicine research because of their pharmaceutical effects. The first reagent that was used suc-cessfully in the treatment of psychosis was a phenthiazine derivative, chlorpromazine. Apart from their activity in neurons, chlorpromazine have also been reported to display anticancer and antibacterial properties. In these studies, we present the synthesis and research on the activ-ity against A549, MDA, MiaPaCa, PC3 and HCT116 cancer cell lines and against S. aureus, S. epi-dermidis, E. coli and P. aeruginosa bacterial strains a series of new tetracyclic chlorpromazine ana-logues containing a quinoline scafford in their structure instead of the benzene ring and various substituents at the thiazine nitrogen. The structure of these novel molecules has been deter-mined by 1H NMR, 13C NMR and HRMS spectral techniques. The seven most active of the twen-ty-four new chlorpromazine analogues tested were selected for study of the mechanism of cyto-toxic action. Their ability to induce apoptosis or necrosis in cancer cells was assessed by flow cytometry analysis. The results obtained confirmed the proapoptotic activity of selected com-pounds, especially in terms of inducing late apoptosis or necrosis in cancer cell lines A549, Mi-aPaCa-2 and HCT-116. Furthermore, studies on the induction of cell cycle arrest suggest that the new chlorpromazine analogues exert antiproliferative effects by inducing cell cycle arrest in the S phase and, consequently, apoptosis.

Overuse and misuse of antibiotics can pose the risks of spreading mutant strains that show antimicrobial resistance (AMR), with negative impact on management of bacterial infections and economic implications on healthcare systems. Research and development of natural antibacterial agents could be a priority in the next years to improve number of effective antibacterial molecules and to reduce AMR phenomenon and its development. The present study identified the most effective concentration and contact time of Thymus vulgaris L. essential oil (TEO) to obtain bactericidal effect in vitro against different Gram + and Gram – bacterial strains. Six clinically isolated (wild types) bacterial strains, (Citrobacter freundii, Enterococcus feciorum, Proteus mirabilis, Acinetobacter cioffi, Pasteurella putrefaciens, Klebsiella pneumoniae) and two ATCC (Staphylococcus aureus and Streptococcus mutans) were tested after 1min, 3min and 5min of contact with TEO. Preliminary results on S. aureus after 24h incubation revealed a TEO concentration of 9.28mg/mL (w/v) that completely inhibited bacteria growth keeping cell viability. Total suppression of bacterial growth at all tested contact times was observed for all tested bacterial strains and the results were confirmed after 48h incubation. Bacterial growth suppression was confirmed even with presence of organic component. These preliminary results showed in vitro antimicrobial efficacy of TEO against different Gram+ and Gram- bacterial strains. Future studies are necessary to confirm the reproducibility of these results even on other strains and to define exactly the molecular mechanisms of EOs, in order to consider TEO as a valid alternative of classic antibiotic therapies and subsequently to reduce the occurrence of AMR.

In the present study, we have followed the hydrothermal path for the synthesis of gold nanoparticles (Au NPs) from the biomaterial Elaeocarpus ganitrus seeds extract, which is a rapid, eco-friendly, non-chemical way. The prepared NPs were thoroughly analyzed by PXRD & HR-TEM studies and also tested for photocatalytic dye degradation and anticancer studies. Besides, antioxidant, antibacterial and anticancer properties of Au NPs were studied. In vitro studies revealed the dose-dependent cytotoxic effect of Au NPs. The prepared nanoparticles showed good cytotoxic impact against Prostate cancer (PC-3) cells line. The results of the present study could contribute to synthesize new and cost-effective drugs from Elaeocarpus ganitrus seeds extract by using bio approach.

Mother's milk is the complete food of choice and the best nutritional source for its bio-immunological richness and its microbiota composed of lactic acid bacteria. The aim of this study was to assess the probiotic potential of the lactic acid bacteria present in breast milk. 34 samples (colostrum, transition milk, mature milk) were taken from breastfeeding women. They were enriched and inoculated onto MRS and MRS+cysteine agar. The sensitivity profile of the bacterial strains was assessed using the diffusion method. PCR was used to search for resistance genes specific to the target bacteria after extraction of the genomic DNA from the isolated strains. Their probiotic capacity was explored by assessing their ability to develop under different conditions. Forty-nine bacterial strains were isolated and Lactobacillus acidophilus was the most representative species in the three types of milk. These strains were able to develop both in hostile conditions and over a wide range of temperatures. They also showed antibacterial activity against pathogenic strains of Salmonella typhimurium, multi-resistant Staphylococcus aureus and Escherichia coli (ATCC25299). These results show that breast milk has potential probiotic activity that can be explored further to make the most of it, particularly in terms of antibiotic therapy.

: Since the COVID-19 pandemic, people have become aware that materials (products) can transmit infection and have begun to focus on questions such as how bacteria and germs, the sources of in-fection, maintain their infectivity on material surfaces, and the extent to which materials can or cannot prevent this. and to what extent materials can and cannot prevent it. The SIAA, a non-profit organization of many Japanese companies, had created an entirely separate interna-tional standard for materials' antibacterial, antiviral, and antibiofilm properties (products). The authors have studied the academic basis for the operation of the standards and were deeply in-volved as researchers in establishing one of the standards. This paper describes the interna-tional standards and some representative examples of the authors' actual use of these standards and explains the current status and future problems.

Schinus terebinthifolius Raddi is a plant native to Brazil. The objective of this work was to analyze the chemical composition, antioxidant and antibacterial potential of essential oils (EOs) from the leaves, fruits and twigs of S. terebinthifolius aiming for their application in food safety. EOs were obtained by hydrodistillation and the chemical composition was determined by gas chromatog-raphy coupled to mass spectrometry. Phenolic compounds were quantified and antioxidant ac-tivity was evaluated using three different methods. The antibacterial activity was determined by the broth microdilution method against foodborne bacteria. In the chemical analysis, 22 com-pounds were identified in the leaves, 13 compounds in the fruits and 37 compounds in the twigs, revealing the presence of the main compounds germacrene D, caryophyllene, α-pinene, β-pinene and γ-gurjunene. EOs showed better antioxidant potential using the β-carotene/linoleic acid method with 40.74, 61.52 and 63.65% oxidation inhibition for leaves, fruits and twigs, respectively. The EO from the leaves showed greater antibacterial potential against Escherichia coli and Staphy-lococcus aureus with a minimum inhibitory concentration (MIC) of 0.62 mg mL-1, values lower than the MIC of sodium nitrite (5.00 mg mL-1), antimicrobial standard synthetic. The activities of pink pepper EOs suggest their potential as a biopreservative in foods.

Novel antibacterial silver nanomaterials have become promising substitutes for traditional antibiotics, because pathogens do not develop resistance to them. However, it is necessary to produce silver nanoparticles with appropriate size and better performance through a green and simple synthesis process. In the present study, Fructus mori-composite silver nanoparticles (M-AgNPs) were greenly synthesized using medicinal plant mulberry fruits (Fructus mori), with silver nitrate (AgNO3) as a precursor. UV-Vis spectroscopy and X-ray diffraction (XRD) indicated the formation of silver nanoparticles with face centered cubic structure. Fourier transform infrared (FTIR) spectroscopy confirmed the reducing and capping effects of mulberry fruits' active components (polyphenols, flavonoids, etc.) on M-AgNPs. The reaction parameters including temperature, time, pH, and concentration of AgNO3 were gradually optimized. The particle size and morphology of M-AgNPs were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM) techniques. The minimum particle size of M-AgNPs was about 30 nm, and they were approximately spherical and equably distributed. The excellent stability of M-AgNPs ensured that no agglomeration occurred for up to 60 days. The antioxidant activity of M-AgNPs was evaluated by 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) assay, and the DPPH radical clearance rate of M-AgNPs was up to about 79%. Greenly synthesized M-AgNPs exhibited better antibacterial activity than chemically synthesized commercial silver nanoparticles (C-AgNPs), due to the active molecules attached to their surfaces. The inhibition zone diameters of M-AgNPs against P.aeruginosa, E.coli and S.aureus were 13.9±0.4、12.2±0.3、12.8±0.7 mm, respectively. Such greenly synthesized AgNPs from medicinal plants have good prospects in the field of biomedicine.

Silybum marianum is a therapeutic plant belonging to the family Asteraceae. It contains silymarin, as its principal component, and has been reported to demonstrate hepatoprotective activity. The study was aimed to investigate the phytochemical constituents, synthesis of nanoparticles, antioxidant activity and antimicrobial effects of the leaf extract. Extracts were synthesized from AgNO3 and characterized via FT-IR, U.V and XRD. The antioxidant activity was determined using DPPH, H2O2 and β-carotene assays. Similarly, all extracts expressed significant DPPH inhibition (IC50) of 5.1, 5.0, 4.7, 2.3, 4.3 and 1.1 (ug/mL), H2O2 of 1.3, 2.2, 4.7, 5.6, 4.0 and 1.0 (ug/mL) from the methanol/water extract, nanoparticles, n-Hexane, ETOAC, n-Butanol and Ascorbic acid (standard) respectively. The extract exerted scavenging activity on β-carotene with a significant IC50 inhibition of 1.5, 0.8, 5.2, 0.8, 2.7, 4.8 at 0 hour and 1.5, 0.8, 5.2, 0.8, 2.7 and 4.8 (ug/mL) after 2 hours water bath incubation at 50°C in the order of the extracts above. Additionally, nanoparticles and plant extracts significantly (p<0.0001) inhibited the growth of bacteria with mean zone of inhibition ranging 7-13 mm and 4-11 mm. This study demonstrated that extracts from different solvents of S. marianum possess significant antioxidant activity, as well as antimicrobial effects which are all concentration dependent. Thus, the result suggests that methanolic/water leaf extract of S. marianum could serve as a potential source of antioxidants and can be explored as a therapeutic agent in free radical induced diseases.