Synthesis of an antimicrobial chitosan film impregnated with ZnO nanoparticles phytosynthesized with Ruta graveolens plant extract

In this study, biopolymer of chitosan-based films were synthesized, which were impregnated with zinc oxide nanoparticles (ZnO NPs) at concentrations of 0, 1, 5 and 10 % w:v to obtain a film with microbicide properties and non-toxic for humans. The ZnO NPs were phytosynthesized with ethanolic extract of Ruta graveolens, by UV-Vis spectrophotometry and Tauc equation were estimated their Band gap energy = 3.37 eV at wavelength of 302 nm. The films characterization by FTIR spectroscopy, swelling test, TGA and DSC indicated that the linking of ZnO NPs with the biopolymer was successfully developed. Finally, to evaluate the potential application of the biopolymer in biomedicine, the microbicidal activity against pathogens Escherichia coli, Staphylococcus aureus and Candida albicans was evaluated. The analyses revealed that the microorganisms are susceptible to the doses of ZnO NPs present in the biopolymer. Resulting the biopolymers with 5 % w:v of ZnO NPs being the most efficient for inhibition zones of 33, 31 and 27 mm that were obtained for each microorganism respectively.

Chitosan-based structures for skin repair: A literature review

The use of chitosan in technological and biomedical applications has gained significant relevance due to its functional properties. Among its biological activities, its hemostatic, analgesic, antibacterial and anti-inflammatory activities make this natural biopolymer one of the most promising in the development of structures for skin repair. Its application and effects can be optimized by exploring efficient structuring techniques. In this context, this review is based on scientific evidence reported in the last decade regarding the development and use of chitosan-based structures in the skin repair process to show the most common structuring methods, the main mechanisms of action of chitosan, and its potential applications in skin repair processes. Additionally, this article brings a compilation of scientific and commercial works on the use of chitosan-based structures, in addition to vitro and/or in vivo results.

A carboxymethyl chitosan and dextran hydrogel with slow and rapid photothermal conversion for sequential promoting burn wound healing and inhibiting scar proliferation

Facilitating swift burn wound healing while effectively preventing scar formation continues to be a considerable challenge in medical practice. In this study, an injectable carboxymethyl chitosan/oxidized dextran/polyvinylpyrrolidone/dopamine (COPD) hydrogel was designed for the effective sequentially promotion of burn wound healing and inhibition of scar formation. The COPD hydrogel precursor solution was injected into the burn wound via a double-barreled syringe and transformed into an adherent hydrogel within 25 s. The inclusion of dopamine imparted good free radical scavenging properties to the hydrogel. In particular, the gradual oxidation of dopamine to polydopamine enabled a unique heat production pattern-initially slow (photothermal conversion efficiency: 30.3 %) and then rapidly temperature increasing (photothermal conversion efficiency: 42.8 %) -under single laser irradiation. The effect of promoting healing at the initial stage of the wound was evaluated by constructing a male C57BL/6 mice model with deep second-degree burns, observation of the wound area, PCR analysis, and immunohistochemical staining. Furthermore, the scar inhibition was confirmed by observing reduced expression levels of α-SMA and COLI, along with a decreased collagen I/III ratio. With tunable mechanical properties (maximum compressive strength of 966.4 ± 51.7 kPa), the COPD hydrogel holds significant promise as an adjunctive photothermal platform for intelligent burn wound management.

Innovative anticancer nanocomposites from Corchorus olitorius mucilage/chitosan/selenium nanoparticles

Cancers are continuing to threaten human health globally; the achievement of effectual and biosafe anticancerous compounds is a precious goal. The extraction of Corchorus olitorius mucilage (Jm) and its usage for selenium nanoparticles (SeNPs) biosynthesis was projected. The innovative formulation of bioactive nanocomposites (NCs) from Jm/SeNPs and chitosan nanoparticles (Cht) was also proposed to apply these NCs as effectual anticancers against CaCo-2 and HeLa cancerous cells. The Jm/SeNPs biosynthesis (mean diameter = 6.45 nm) was innovatively achieved and confirmed using infrared and ultraviolet-visible analysis. The constructions of different NCs were done (N1: 2Jm/SeNPs:1Cht; N2: 1Jm/SeNPs:1Cht; and N3: 1Jm/SeNPs:2Cht) with mean particles' diameter of 88.41, 46.86 and 69.35 nm, respectively. The cytotoxicity assay of constructed NCs indicated their potentialities to suppress examined cells; N1 (negatively charged; -16.2 mV) was the most forceful with IC50 of 12.36 and 73.15 mg/L against CaCo-2 and HeLa cells, respectively. The scanning microscopy imaging of treated CaCo-2 cells with N1 of Cht/Jm/SeNPs indicated that the NCs led to remarkable apoptotic destructions of treated cells, including cell shrinkage, membrane blebbing, cytoplasmic vacuolization, cell debris and apoptotic indices. The innovative NCs from Cht/Jm/SeNPs are promisingly recommended as effectual, natural and bioactive anticancer formulations against human cancers.

Chitosan Hemostatic Dressings: Properties and Surgical Applications

Wounds caused by trauma and/or surgery represent a significant challenge in contemporary medical practice, requiring innovative approaches to promote optimal healing and reduce the risk of bleeding and complications resulting from it. In this context, chitosan, a natural polysaccharide derived from chitin, represents an ideal material for the study and application of medical devices, in the form of dressings, in wound management for pre- and/or post-operative wounds due to its ability to induce hemostasis and its high biocompatibility with biological tissues. The aim of this work was to discuss the structural characteristics, properties and application of chitosan-based hemostatic dressings in hemostatic processes resulting from pre- or post-surgical approaches.

Advances in chitosan and chitosan derivatives for biomedical applications in tissue engineering: An updated review

In recent years, chitosan (CS) has received much attention as a functional biopolymer for various applications, especially in the biomedical field. It is a natural polysaccharide created by the chemical deacetylation of chitin (CT) that is nontoxic, biocompatible, and biodegradable. This natural polymer is difficult to process; however, chemical modification of the CS backbone allows improved use of functional derivatives. CS and its derivatives are used to prepare hydrogels, membranes, scaffolds, fibers, foams, and sponges, primarily for regenerative medicine. Tissue engineering (TE), currently one of the fastest-growing fields in the life sciences, primarily aims to restore or replace lost or damaged organs and tissues using supports that, combined with cells and biomolecules, generate new tissue. In this sense, the growing interest in the application of biomaterials based on CS and some of its derivatives is justifiable. This review aims to summarize the most important recent advances in developing biomaterials based on CS and its derivatives and to study their synthesis, characterization, and applications in the biomedical field, especially in the TE area.

Chitosan-Based Biomaterial in Wound Healing: A Review

Wound healing is an evolving and intricate technique that is vital to the restoration of tissue integrity and function. Over the past few decades, chitosan a biopolymer derived from chitin, became known as an emerging biomaterial in the field of healing wounds due to its distinctive characteristics including biocompatibility, biodegradability, affinity to biomolecules, and wound-healing activity. This natural polymer exhibits excellent healing capabilities by accelerating the development of new skin cells, reducing inflammation, and preventing infections. Due to its distinct biochemical characteristics and innate antibacterial activity, chitosan has been extensively researched as an antibacterial wound dressing. Chronic wounds, such as diabetic ulcers and liver disease, are a growing medical problem. Chitosan-based biomaterials are a promising solution in the domain of wound care. The article analyzes the depth of chitosan-based biomaterials and their impact on wound healing and also the methods to enhance the advantages of chitosan by incorporating bioactive compounds. This literature review is aimed to improve the understanding and knowledge about biomaterials and their use in wound healing.

Formation Kinetics and Antimicrobial Activity of Silver Nanoparticle Dispersions Based on N-Reacetylated Oligochitosan Solutions for Biomedical Applications

The paper presents the results of the synthesis, a detailed kinetics study, and an investigation of the biological activity of silver nanoparticles (AgNPs) in aqueous solutions of N-reacetylated oligochitosan hydrochloride. UV-visible spectrophotometry and dynamic light scattering were employed to control silver ion reduction. The process was observed to follow a pseudo-first-order law. Transmission and scanning electron microscopy demonstrated that AgNPs ranging in size from 10 to 25 nm formed aggregates measuring 60 to 90 nm, with the aggregate surface coated by a 2-4 nm chitosan shell. X-ray microanalysis and powder X-ray diffractometry were used to study the phase composition, identifying two crystalline phases, nanocrystalline silver and AgCl, present in the dispersions. The antibacterial effect was assessed using the serial dilution method for dispersions with varying degrees of Ag+ conversion. Nanodispersions exhibited significant activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, and Staphylococcus aureus. Interestingly, the activity did not appear to be heavily influenced by the presence of the AgCl phase or the concentration of Ag+ ions. These synthesized dispersions hold promise for the development of materials tailored for biomedical applications.

Biodegradable trimethyl chitosan nanofiber mats by electrospinning as bioabsorbable dressings for wound closure and healing

The paper aimed to prepare quaternary chitosan-based nanofibers as bioabsorbable wound dressings. To this aim, fully biodegradable chitosan/N,N,N-trimethyl chitosan (TMC) nanofibers were designed and prepared via electrospinning, using poly(ethylene glycol) as sacrificial additive. The new biomaterials were structurally and morphologically characterized by FTIR and NMR spectroscopy, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy, and their properties required for wound dressings application were investigated and discussed in detail. Thus, the nanofiber behavior was investigated by swelling, dynamic vapor sorption, and in vitro biodegradation in media mimicking the wound exudate. The mechanical properties were analysed from the stress-strain curves, the bioadhesivity from the texture analysis and the mucoadhesivity from the Zeta potential and transmittance measurements. The antimicrobial activity was assessed against S. aureus and E. coli strains, and the biocompatibility was tested in vitro on normal human dermal fibroblasts, and in vivo on rats. The application of the fiber mats with the best balance of properties as dressings on deep burn wound models in rats showed wound closure and active healing, with fully restoration of epithelia. It was concluded that the combination of chitosan with TMC into nanofibers provides new potential bioabsorbable wound dressing, opening new perspectives in regenerative medicine.

Green Nanomaterials for Smart Textiles Dedicated to Environmental and Biomedical Applications

Smart textiles recently reaped significant attention owing to their potential applications in various fields, such as environmental and biomedical monitoring. Integrating green nanomaterials into smart textiles can enhance their functionality and sustainability. This review will outline recent advancements in smart textiles incorporating green nanomaterials for environmental and biomedical applications. The article highlights green nanomaterials' synthesis, characterization, and applications in smart textile development. We discuss the challenges and limitations of using green nanomaterials in smart textiles and future perspectives for developing environmentally friendly and biocompatible smart textiles.

Thyme/garlic essential oils loaded chitosan–alginate nanocomposite: Characterization and antibacterial activities

For controlling pathogenic bacteria using nanopolymer composites with essential oils, the formulation of chitosan/alginate nanocomposites (CS/ALG NCs) loaded with thyme oil, garlic oil, and thyme/garlic oil was investigated. Oils were encapsulated in CS/ALG NCs through oil-in-water emulsification and ionic gelation. The CS/ALG NCs loaded with oils of garlic, thyme, and garlic–thyme complex had mean diameters of 143.8, 173.9, and 203.4 nm, respectively. They had spherical, smooth surfaces, and zeta potential of +28.4 mV for thyme–garlic-loaded CS/ALG NCs. The bactericidal efficacy of loaded NCs with mixed oils outperformed individual loaded oils and ampicillin, against foodborne pathogens. Staphylococcus aureus was the most susceptible (with 28.7 mm inhibition zone and 12.5 µg·mL−1 bactericidal concentration), whereas Escherichia coli was the most resistant (17.5 µg·mL−1 bactericidal concentration). Scanning electron microscopy images of bacteria treated with NCs revealed strong disruptive effects on S. aureus and Aeromonas hydrophila cells; treated cells were totally exploded or lysed within 8 h. These environmentally friendly nanosystems might be a viable alternative to synthetic preservatives and be of interest in terms of health and food safety.

Novel Wound Dressing Based on Postbiotic/Chitosan Film Accelerates Cutaneous Wound Healing

Background: Wound healing is a complex and overlapping process involving immune cells, cytokines, and growth factors. Objectives: This study aimed to design and evaluate a novel wound dressing based on postbiotic/chitosan in accelerating wound healing. Methods: Lactobacillus reuteri PTCC1655 was cultured, and the cell-free supernatant (postbiotic) was obtained by medium centrifugation. The films were prepared using the solvent casting method and evaluated in terms of water absorption index, water vapor transmission rate, and antimicrobial properties. Forty-five male Wistar rats were subjected to a full-thickness excisional wound to assess the wound healing potential. The rats were randomly divided into ctrl-, chitosan, and postbiotic groups. The time-course histological and gene expression analysis was performed to compare the dressing efficacy. Results: The films showed proper water absorption and water vapor transmission rate and inhibited the pathogens commonly associated with wound infection. The postbiotic film improved wound healing by modulating the inflammatory phase, increasing collagen and elastin deposition, and enhancing angiogenesis based on the histological results. The gene expression assay showed that the postbiotic film accelerated wound healing by improving the expression of inflammatory mediators (IL-6 and TNF-α) and anti-inflammatory mediators (TGF-β and VEGF). Conclusions: The cell-free supernatant/chitosan/polyethylene glycol (CFS/CS/PEG) biodegradable film could be introduced as a novel dressing for cutaneous wound healing. This transparent film enhances cutaneous wound healing by modulating infiltrated immunity cells and expressing inflammatory/anti-inflammatory cytokines.