Search Results (6,564)

This study explores the use of pine wood biochar (BC) waste gasified at 950 °C as fillers in polymer matrices to create BC@biopolymer composites with perspectives in groundwater remediation. Four biochar samples underwent different sieving and grinding processes and were extensively characterized via UV–Vis, FTIR, and FESEM–EDS, highlighting the fact that that BCs are essentially graphitic in nature with a sponge-like morphology. The grinding process influences the particle size, reducing the specific surface area by about 30% (evaluated by BET). The adsorption performances of raw BC were validated via an adsorption isotherm using trichloroethylene (TCE) as a model contaminant. A selected BC sample was used to produce hydrophilic, stable polymer composites with chitosan (CS), alginate (ALG), potato starch (PST), and sodium carboxymethylcellulose (CMC) via a simple blending approach. Pilot sedimentation tests over 7 days in water identified BC@PST and BC@CMC as the most stable suspensions due to a combination of both hydrogen bonds and physical entrapment, as studied by FTIR. BC@CMC showed optimal distribution and retention properties without clogging in breakthrough tests. The study concludes that biopolymer-based biochar composites with improved stability in aqueous environments hold significant promise for addressing various groundwater pollution challenges. Full article

This study evaluates the antimicrobial efficacy of chitosan nanoparticles (CNPs), varying in size, against clinical isolates of Mycobacterium tuberculosis (MTB), E. coli, S. aureus, E. faecalis, and C. albicans, as well as the antimicrobial effects of aqueous extracts and lyophilized powders of Allium (garlic) species. CNPs were synthesized through ionotropic gelation and characterized by Z potential, hydrodynamic diameter (dynamic light scattering, DLS), and SEM. Aqueous garlic extracts were prepared via decoction. We assessed antimicrobial activity using disk diffusion and broth microdilution methods; in addition, a modified agar proportion method in blood agar was used for antimicrobial activity against MTB. CNPs inhibited MTB growth at 300 μg for 116.6 nm particles and 400 μg for 364.4 nm particles. The highest antimicrobial activity was observed against E. faecalis with nanoparticles between 200 and 280 nm. Allium sativum extract produced inhibition for C. albicans at 100 μg. The results indicate that CNPs possess significant antimicrobial properties against a range of pathogens, including MTB, at high concentrations. On the other hand, aqueous Allium sativum extracts exhibited antimicrobial activity. Nonetheless, due to their instability in solution, the use of lyophilized Allium sativum powder is preferable. Full article

Chitosan nanoparticles (CSNPs) are promising vehicles for targeted and controlled drug release. Recognized for their biodegradability, biocompatibility, low toxicity, and ease of production, CSNPs represent an effective approach to drug delivery. Encapsulating drugs within nanoparticles (NPs) provides numerous benefits compared to free drugs, such as increased bioavailability, minimized toxic side effects, improved delivery, and the incorporation of additional features like controlled release, imaging agents, targeted delivery, and combination therapies with multiple drugs. Keys parameters in nanomedicines are drug loading content and drug loading efficiency. Most current NP systems struggle with low drug loading, presenting a significant challenge to the field. This review summarizes recent research on developing CSNPs with high drug loading capacity, focusing on various synthesis strategies. It examines CSNP systems using different materials and drugs, providing details on their synthesis methods, drug loadings, encapsulation efficiencies, release profiles, stability, and applications in drug delivery. Additionally, the review discusses factors affecting drug loading, providing valuable guidelines for future CSNPs’ development. Full article

Mesoporous silica nanoparticles (MSNs) are promising drug carriers for cancer therapy. Their functionalization with ligands for specific tissue/cell targeting and stimuli-responsive cap materials for sealing drugs within the pores of MSNs is extensively studied for biomedical and pharmaceutical applications. The objective of the present work was to establish MSNs as ideal nanocarriers of anticancer drugs such as 5-FU and silymarin by exploiting characteristics such as their large surface area, pore size, and biocompatibility. Furthermore, coating with various biopolymeric materials such as carboxymethyl chitosan–dopamine and hyaluronic acid–folic acid on their surface would allow them to play the role of ligands in the process of active targeting to tumor cells in which there is an overexpression of specific receptors for them. From the results obtained, it emerged, in fact, that these hybrid nanoparticles not only inhibit the growth of glioblastoma and breast cancer cells, but also act as pH-responsive release systems potentially useful as release vectors in tumor environments. Full article

Ischemia/reperfusion (I/R) injury following myocardial infarction is a major cause of cardiomyocyte death and impaired cardiac function. Although clinical data show that metformin is effective in repairing cardiac I/R injury, its efficacy is hindered by non-specific targeting during administration, a short half-life, frequent dosing, and potential adverse effects on the liver and kidneys. In recent years, injectable hydrogels have shown substantial potential in overcoming drug delivery challenges and treating myocardial infarction. To this end, we developed a natural polymer hydrogel system comprising methacryloylated chitosan and methacryloylated gelatin modified with polyaniline conductive derivatives. In vitro studies demonstrated that the optimized hydrogel exhibited excellent injectability, biocompatibility, biodegradability, suitable mechanical properties, and electrical conductivity. Incorporating metformin into this hydrogel significantly extended the administration cycle, mitigated mitochondrial damage, decreased abnormal ROS production, and enhanced cardiomyocyte function. Animal experiments indicated that the metformin/hydrogel system reduced arrhythmia incidence, infarct size, and improved cardiac mitochondrial and overall cardiac function, promoting myocardial repair in I/R injury. Overall, the metformin-loaded conductive hydrogel system effectively mitigates mitochondrial oxidative damage and improves cardiomyocyte function, thereby offering a theoretical foundation for the potential application of metformin in cardioprotection. Full article

The preservation of meat via sustainable methods and packaging is an area of continued interest driven by the need to address food security. The use of biomaterial films and coatings has gained significant attention due to their non-toxicity and biodegradability compared with conventional synthetic films. Starch and chitosan are sustainable sources for the preparation of films/coatings owing to their relatively low cost, natural abundance derived from numerous sources, biocompatibility, biodegradability, and antimicrobial, antioxidant, and film-forming attributes. These remarkable features have notably increased the shelf life of meat by inhibiting lipid oxidation and microbial activity in food products. Furthermore, recent studies have successfully incorporated binary biopolymer (starch and chitosan) systems to combine their beneficial properties upon composite formation. This literature review from 2020 to the present reveals that chitosan- and starch-based films and coatings have potential to contribute to enhanced food security and safety measures whilst reducing environmental issues and improving sustainability, compared with conventional synthetic materials. Full article

In this study, environmentally friendly and low-cost biomass materials were selected as wood flame retardants. Three polyelectrolyte flame-retardant coatings made from chitosan (CS), tea polyphenols (TP), soybean isolate protein (SPI), and banana peel powder (BBP) were constructed on wood surfaces by layer-by-layer (LBL) self-assembly. The results of SEM-EDS and FT-IR analyses confirmed the successful deposition of CS-TP, CS-SPI, and CS-BPP on the wood surface, and the content of N element increased. The TG results showed that the initial decomposition temperature and the maximum thermal decomposition temperature of the coated wood specimens decreased, while the char residue increased significantly. This is due to the earlier pyrolysis of CS-TP, CS-SPI, and CS-BBP. This shows that the three polyelectrolyte flame-retardant coatings can improve the thermal stability of wood. The combustion behavior of the wood specimen was observed by exposure to combustion; the coated wood could self-extinguish within a certain period of time after ignition, and the flame-retardant performance was improved to a certain extent. SEM and EDS characterization analyses of the carbon residue after combustion showed that the coated wood charcoal layer was denser, which could effectively block heat and combustible gas. Full article

Chitosan was subjected to a crosslinking reaction with three polyhydroxylated diacids (glucaric (GlcA), mannaric (ManA), and mucic (MucA) acids) that only differ in the spatial orientation of their hydroxyl groups. This work aimed to obtain experimental evidence of the impact of the three-dimensional arrangement of the crosslinkers on the resulting properties of the products. In all the cases, the products were hydrogels, and their chemical structures were fully elucidated by FT-IR spectroscopy and conductometric titration. Thermogravimetric and morphological studies were also carried out. The specific surface area of all the products was similar and higher than that of native chitosan. Moreover, all hydrogels were characterized in terms of viscoelastic properties and long-term stability under external perturbation. Furthermore, their lead adsorption efficiency and swelling capacity were assessed. Despite the resemblant chemical structure in all the hydrogels, Ch/ManA exhibited the highest lead adsorption capacity, (Ch/ManA: 93.8 mg g⁻¹, Ch/GlcA: 82.9 mg g⁻¹, Ch/MucA: 79.2 mg g⁻¹), while Ch/GlcA exhibited a remarkably higher swelling capacity (i.e., ~30% more than Ch/MucA and ~40% more than Ch/ManA). The results obtained herein evidenced that the selection of the polyhydroxylated crosslinker with the appropriate three-dimensional structure could be crucial to finely adjust the final materials’ features. Full article

The objective of this study was to examine the effects of varying levels of dietary chitosan supplementation on mitigating cadmium stress and its influence on growth performance, serum biochemical indices, antioxidant capacity, immune response, inflammatory response, and the expression of related genes in juvenile Genetically Improved Farmed Tilapia (GIFT, Oreochromis niloticus). Five groups of juvenile tilapias (initial body weight 21.21 ± 0.24 g) were fed five diets with different levels (0%, 0.5%, 1.0%, 1.5%, and 2.0%) of chitosan supplementation for 60 days under cadmium stress (0.2 mg/L Cd²⁺). The findings indicated that, compared with the 0% chitosan group, dietary chitosan could significantly increase (p < 0.05) the final weight (Wf), weight gain rate (WGR), specific growth rate (SGR), daily growth index (DGI), and condition factor (CF), while the feed conversion ratio (FCR) expressed the opposite trend in juvenile GIFT. Dietary chitosan could significantly increase (p < 0.05) the activities (contents) of cholinesterase (CHE), albumin (ALB), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), acid phosphatase (ACP), and lysozyme (LZM), while glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), and complement 3 (C3) in the serum of juvenile GIFT expressed the opposite trend. Dietary chitosan could significantly increase (p < 0.05) the activities of superoxide dismutase (SOD) and catalase (CAT) and significantly decrease (p < 0.05) the activities (contents) of glutathione S-transferase (GST), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) in the serum of juvenile GIFT. Dietary chitosan could significantly increase (p < 0.05) the activities (contents) of CAT, GST, GSH-Px, and total antioxidant capacity (T-AOC) and significantly decrease (p < 0.05) the contents of MDA in the liver of juvenile GIFT. Dietary chitosan could significantly increase (p < 0.05) the activities (contents) of SOD, GSH-Px, T-AOC, Na⁺-K⁺-ATPase, and Ca²⁺-ATPase and significantly decrease (p < 0.05) the activities (contents) of CAT, GST, and MDA in the gills of juvenile GIFT. Dietary chitosan could significantly up-regulate (p < 0.05) the gene expression of cat, sod, gst, and gsh-px in the liver of juvenile GIFT. Dietary chitosan could significantly up-regulate (p < 0.05) the gene expression of interferon-γ (inf-γ) in the gills and spleen and significantly down-regulate (p < 0.05) the gene expression of inf-γ in the liver and head kidney of juvenile GIFT. Dietary chitosan could significantly down-regulate (p < 0.05) the gene expression of interleukin-6 (il-6), il-8, and tumor necrosis factor-α (tnf-α) in the liver, gills, head kidney, and spleen of juvenile GIFT. Dietary chitosan could significantly up-regulate (p < 0.05) the gene expression of il-10 in the liver, gills, head kidney, and spleen of juvenile GIFT. Dietary chitosan could significantly up-regulate (p < 0.05) the gene expression of transforming growth factor-β (tgf-β) in the liver and significantly down-regulate (p < 0.05) the gene expression of tgf-β in the head kidney and spleen of juvenile GIFT. In conclusion, dietary chitosan could mitigate the impact of cadmium stress on growth performance, serum biochemical indices, antioxidant capacity, immune response, inflammatory response, and related gene expression in juvenile GIFT. According to the analysis of second-order polynomial regression, it was found that the optimal dietary chitosan levels in juvenile GIFT was approximately 1.42% to 1.45%, based on its impact on Wf, WGR, SGR, and DGI. Full article

Cancer and bacterial infections rank among the most significant global health threats. accounting for roughly 25 million fatalities each year. This statistic underscores the urgent necessity for developing novel drugs, enhancing current treatments, and implementing systems that boost their bioavailability to achieve superior therapeutic outcomes. Liposomes have been recognised as effective carriers; nonetheless, they encounter issues with long-term stability and structural integrity, which limit their pharmaceutical applicability. Chitosomes (chitosan-coated liposomes) are generally a good alternative to solve these issues. This research aims to demonstrate the effective individual encapsulation of ciprofloxacin (antibacterial, hydrophilic) and etoposide (anticancer, hydrophobic), within chitosomes to create more effective drug delivery systems (oral administration for ciprofloxacin, parenteral administration for etoposide). Thus, liposomes and chitosomes were prepared using the thin-film hydration technique and were characterised through ATR-FTIR, Dynamic Light Scattering (DLS), zeta potential, and release profiling. In both cases, the application of chitosomes enhanced long-term stability in size and surface charge. Chitosome-encapsulated ciprofloxacin formulations exhibited a slower and sustained release profile, while the combined effect of etoposide and chitosan showed heightened efficacy against the glioblastoma cell line U373. Therefore, coating liposomes with chitosan improved the encapsulation system’s properties, resulting in a promising method for drug delivery. Full article

Currently, the number of patients with cancer is expanding consistently because of a low quality of life. For this reason, the therapies used to treat cancer have received a lot of consideration from specialists. Numerous anticancer medications have been utilized to treat patients with cancer. However, the immediate utilization of anticancer medicines leads to unpleasant side effects for patients and there are many restrictions to applying these treatments. A number of polymers like cellulose, chitosan, Polyvinyl Alcohol (PVA), Polyacrylonitrile (PAN), peptides and Poly (hydroxy alkanoate) have good properties for the treatment of cancer, but the nanofibers-based target and controlled drug delivery system produced by the co-axial electrospinning technique have extraordinary properties like favorable mechanical characteristics, an excellent release profile, a high surface area, and a high sponginess and are harmless, bio-renewable, biofriendly, highly degradable, and can be produced very conveniently on an industrial scale. Thus, nanofibers produced through coaxial electrospinning can be designed to target specific cancer cells or tissues. By modifying the composition and properties of the nanofibers, researchers can control the release kinetics of the therapeutic agent and enhance its accumulation at the tumor site while minimizing systemic toxicity. The core–shell structure of coaxial electrospun nanofibers allows for a controlled and sustained release of therapeutic agents over time. This controlled release profile can improve the efficacy of cancer treatment by maintaining therapeutic drug concentrations within the tumor microenvironment for an extended period. Full article

This study describes the comparison between the interaction of a series of peptide-functionalized chitosan-based nanocapsules and liposomes with two cell lines, i.e., mouse macrophages RAW 264.7 and human endothelial cells EA.hy926. Both types of nanocarriers are loaded with magnetic nanoparticles and designed for anti-inflammatory therapy. The choice of these magnetic nanostructures is argued based on their advantages in terms of size, morphology, chemical composition, and the multiple possibilities of modifying their surface. Moreover, active targeting might be ensured by using an external magnetic field. To explore the impact of chitosan-based nanocapsules and liposomes on cell cytophysiology, the cell viability, using the MTT assay, and cell morphology were investigated. The results revealed low to moderate cytotoxicity of free nanocapsules and significant cytotoxicity induced by chitosan-coated liposomes loaded with dexamethasone, confirming its release from the delivery system. Thus, after 48 h of treatment with nanocapsules, the viability of RAW 264.7 cells varied between 88.18% (OCNPM-1I, 3.125 µg/mL) and 76.37% (OCNPM-1, 25 µg/mL). In the same conditions, EA.hy926 cell viability was between 99.91% (OCNPM-3, 3.125 µg/mL) and 75.15% (OCNPM-3, 25 µg/mL) at the highest dose (25 µg/mL), the values being comparable for both cell lines. Referring to the cell reactivity after dexamethasone-loaded liposome application, the lowest viability of RAW 264.7 cells was 41.25% (CLDM5CP-1, 25 µg/mL) and 58.20% (CLDMM2CP-1 1.25 µg/mL) in the endothelial cell line, proving a selective character of action of nanocarriers. The cell morphology test, performed to support and confirm the results obtained by the MTT test, revealed a differentiated response for the two types of nano-carriers. As expected, an intense cytotoxic effect in the case of dexamethasone-loaded liposomes and a lack of cytotoxicity for drug-free nanocapsules were noticed. Therefore, our study demonstrated the biocompatible feature of the studied nanocarriers, which highlights them for future research as potential drug delivery systems for pharmacological applications, including anti-inflammatory therapy. Full article

Ischemic events can culminate in acute myocardial infarction, which is generated by irreversible cardiac lesions that cannot be restored due to the limited regenerative capacity of the heart. Cardiac cell therapy aims to replace injured or necrotic cells with healthy and functional cells. Tissue engineering and cardiovascular regenerative medicine propose therapeutic alternatives using biomaterials that mimic the native extracellular environment and improve cellular and tissue functionality. This investigation evaluates the effect of thermosensitive hydrogels, and murine fetal ventricular cardiomyocytes encapsulated in thermosensitive hydrogels, on the contractile function of cardiomyocyte regeneration during an ischemic event. Chitosan and hydrolyzed collagen thermosensitive hydrogels were developed, and they were physically and chemically characterized. Likewise, their biocompatibility was evaluated through cytotoxicity assays by MTT, LDH, and their hemolytic capacity. The hydrogels, and cells inside the hydrogels, were used as an intervention for primary cardiomyocytes under hypoxic conditions to determine the restoration of the contractile capacity by measuring intracellular calcium levels and the expressions of binding proteins, such as a-actinin and connexin 43. These results evidence the potential of natural thermosensitive hydrogels to restore the bioelectrical functionality of ischemic cardiomyocytes. Full article

The roughness of woven fabric surface has so far been mainly investigated as a key characteristic of comfort in contact with the skin. The analysis of roughness can be extended to various contexts and applications, becoming an important tool for understanding how textile materials react in interaction with different finishing agents, as well as for gaining insight into the durability and effectiveness of treatments. This research presents a comprehensive study on the impact of alkaline hydrolysis and chitosan coating on the roughness of polyester woven fabric, utilizing both novel and adapted methods. The study employed contact and optical methods to analyze fabric and fiber surface characteristics, highlighting the significance of roughness profile parameters in understanding material changes post-treatment. The investigation revealed that mechanical action, alkaline medium, washing temperature, and detergent residues contribute to fabric erosion and modification during washing, with chitosan coatings creating pronounced surface irregularities. Comparative analysis showed significant fabric roughness changes post-washing, while fiber roughness changes were treatment specific. Despite initial increases in fiber roughness due to treatments, their durability decreased after washing. These findings emphasize the importance of roughness analysis in optimizing textile finishing processes and washing cycles, impacting both comfort and treatment efficacy. Full article

Stem cell-based therapy holds promise for cartilage regeneration in treating knee osteoarthritis (KOA). Injectable hydrogels have been developed to mimic the extracellular matrix (ECM) and facilitate stem cell growth, proliferation, and differentiation. However, these hydrogels face limitations such as poor mechanical strength, inadequate biocompatibility, and suboptimal biodegradability, collectively hindering their effectiveness in cartilage regeneration. This study introduces an injectable, biodegradable, and self-healing hydrogel composed of chitosan–PEG and PEG–dialdehyde for stem cell delivery. This hydrogel can form in situ by blending two polymer solutions through injection at physiological temperature, encapsulating human adipose-derived stem cells (hADSCs) during the gelation process. Featuring a 3D porous structure with large pore size, optimal mechanical properties, biodegradability, easy injectability, and rapid self-healing capability, the hydrogel supports the growth, proliferation, and differentiation of hADSCs. Notably, encapsulated hADSCs form 3D spheroids during proliferation, with their sizes increasing over time alongside hydrogel degradation while maintaining high viability for at least 10 days. Additionally, hADSCs encapsulated in this hydrogel exhibit upregulated expression of chondrogenic differentiation genes and proteins compared to those cultured on 2D surfaces. These characteristics make the chitosan–PEG/PEG–dialdehyde hydrogel–stem cell construct suitable for direct implantation through minimally invasive injection, enhancing stem cell-based therapy for KOA and other cell-based treatments. Full article