In vivo assessment of the durable, green and in situ bio-functional cotton fabrics based carboxymethyl chitosan nanohybrid for wound healing application

Carboxymethyl cellulose/sodium alginate hydrogel with anti-inflammatory capabilities for accelerated wound healing; In vitro and in vivo study

Recently, managing the chronic skin wounds has become increasingly challenging for healthcare professionals due to the intricate orchestration of cellular and molecular processes involved that lead to the uncontrollable inflammatory reactions which hinder the healing process. Therefore, different types of wound dressings with immunomodulatory properties have been developed in recent years to effectively regulate the immune responses, enhance angiogenesis, promote re-epithelialization, and accelerate the wound healing process. This study aims to develop a new type of immunomodulatory wound dressing utilizing carboxymethyl cellulose (CMC)/sodium alginate (Alg)-simvastatin (SIM) to simultaneously enhance the inflammatory responses and the wound healing ratio. The CMC/Alg-SIM hydrogels exhibited appropriate swelling ratio, water vapor transmission rate, and desirable degradation rate, depending on the SIM content. The fabricated dressing showed sustained release of SIM (during 5 days) that improved the proliferation of skin cells. According to the in vitro findings, the CMC/Alg-SIM hydrogel exhibited controlled pro-inflammatory responses (decreased 2.5- and 1.6-times IL-6 and TNF-α, respectively) and improved secretion of anti-inflammatory cytokines (increased 1.5- and 1.3-times IL-10 and TGF-β, respectively) in comparison with CMC/Alg. Furthermore, the CMC/Alg-SIM hydrogel facilitated rapid wound healing in the rat model with a full-thickness skin defect. After 14 days post-surgery, the wound healing ratio in the CMC/Alg hydrogel group (∼93%) was significantly greater than the control group (∼58%). Therefore, the engineered CMC/Alg-SIM hydrogel with desired immunomodulatory properties possesses the potential to enhance and accelerate skin regeneration for the management of chronic wound healing.

Emerging trends and challenges in polysaccharide derived materials for wound care applications: A review

Polysaccharides are favourable and promising biopolymers for wound care applications due to their abundant natural availability, low cost and excellent biocompatibility. They possess different functional groups, such as carboxylic, hydroxyl and amino, and can easily be modified to obtain the desirable properties and various forms. This review systematically analyses the recent progress in polysaccharides derived materials for wound care applications, emphasizing the most commonly used cellulose, chitosan, alginate, starch, dextran and hyaluronic acid derived materials. The distinctive attributes of each polysaccharide derived wound care material are discussed in detail, along with their different forms, i.e., films, membranes, sponges, nanoemulsions, nanofibers, scaffolds, nanocomposites and hydrogels. The processing methods to develop polysaccharides derived wound care materials are also summarized. In the end, challenges related to polysaccharides derived materials in wound care management are listed, and suggestions are given to expand their utilization in the future to compete with conventional wound healing materials.

Regulating molecular brush structure on cotton textiles for efficient antibacterial properties

The molecular brush structures have been developed on cotton textiles for long-term and efficient broad-spectrum antimicrobial performances through the cooperation of alkyl-chain and quaternary ammonium sites. Results show that efficient antibacterial performances can be achieved by the regulation of the alkyl chain length and quaternary ammonium sites. The antibacterial efficiency of the optimized molecular brush structure of [3-(N,N-Dimethylamino)propyl]trimethoxysilane with cetyl modification on cotton textiles (CT-DM-16) can reach more than 99 % against both E. coli and S. aureus. Alkyl-chain grafting displayed significantly improvement in the antibacterial activity against S. aureus with (N,N-Diethyl-3-aminopropyl)trimethoxysilane modification on cotton textiles (CT-DE) based materials. The positive N sites and alkyl chains played important roles in the antibacterial process. Proteomic analysis reveals that the contributions of cytoskeleton and membrane-enclosed lumen in differentially expressed proteins have been increased for the S. aureus antibacterial process, confirming the promoted puncture capacity with alkyl-chain grafting. Theoretical calculations indicate that the positive charge of N sites can be enhanced through alkyl-chain grafting, and the possible distortion of the brush structure in application can further increase the positive charge of N sites. Uncovering the regulation mechanism is considered to be important guidance to develop novel and practical antibacterial materials.

Co-release of nitric oxide and L-arginine from poly (β-amino ester)-based adhesive reprogram macrophages for accelerated wound healing and angiogenesis in vitro and in vivo

Recently, insufficient angiogenesis and prolonged inflammation are crucial challenges of chronic skin wound healing. The sustained release of L-Arginine (L-Arg) and nitric oxide (NO) production can control immune responses, improve angiogenesis, enhance re-epithelialization, and accelerate wound healing. Here, we aim to improve wound healing via the controlled release of NO and L-Arg from poly (β-amino ester) (PβAE). In this regard, PβAE is functionalized with methacrylate poly-L-Arg (PAMA), and the role of PAMA content (50, 66, and 75 wt%) on the adhesive properties, L-Arg, and NO release, as well as collagen deposition, inflammatory responses, and angiogenesis, is investigated in vitro and in vivo. Results show that the PAMA/ PβAE could provide suitable adhesive strength (~25 kPa) for wound healing application. In addition, increasing the PAMA content from 50 to 75 wt% results in an increased release of L-Arg (approximately 1.4-1.7 times) and enhanced NO production (approximately 2 times), promoting skin cell proliferation and migration. The in vitro studies also show that compared to PβAE hydrogel, incorporation of 66 wt% PAMA (PAMA 66 sample) reveals superior collagen I synthesis (~ 3-4 times) of fibroblasts, controlled pro-inflammatory and improved anti-inflammatory cytokines secretion of macrophages, and accelerated angiogenesis (~1.5-2 times). In vivo studies in a rat model with a full-thickness skin defect also demonstrate the PAMA66 sample could accelerate wound healing (~98 %) and angiogenesis, compared to control (untreated wound) and Tegaderm™ commercial wound dressing. In summary, the engineered multifunctional PAMA functionalized PβAE hydrogel with desired NO and L-Arg release, and adhesive properties can potentially reprogram macrophages and accelerate skin healing for chronic wound healing.

Formulating of the sustained release of Tebuconazole pesticide using chitosan aerogel reinforced NFC/CaCO3 nanocomposite

Chitosan-based aerogels were fabricated through utilizing of nanofibrillated cellulose (NFC)/CaCO3 composites. Chitosan aerogel and extra three aerogels loaded different concentrations of NFC/CaCO3 were investigated to explore their release efficiency of Tebuconazole pesticides. Results obtained from ATR-FTIR showed a remarkable decline of the characterized chitosan hydroxyl group peak prolonging with appearance of new peaks assigned to the inclusion of inorganic calcium element. Also, SEM images showed chitosan aerogel with regular porous structure increased by incorporation with of NFC/CaCO3 nanocomposite, while EDS affirmed the presence of calcium element rather pristine chitosan aerogel. In addition to this, the physical characterizations showed significant improvement in swelling properties for aerogels incorporated NFC/CaCO3 nanocomposite at low ratios. Chitosan aerogel reinforced NFC/CaCO3 nanocomposite exhibited benefit on loading and release efficiency of Tebuconazole. All samples showed accessibility to column release method with fastest release at low slow rate 2 mL/min as giving chance for diffusion and solubility of ingredient, while release increase as heat increase as result of pore expansion. In conclusion, chitosan aerogels incorporated calcium carbonate showed better-sustained release of Tebuconazole pesticides than pristine chitosan aerogel. The produced aerogels loaded NFC/CaCO3 nanocomposite could be promising for controlled release of pesticides at water-streams in agriculture sector.

Biodegradable wound dressing-based collagen/hyaluronic acid loaded antibacterial agents for wound healing application

Three biodegradable wound dressing based on binary Collagen (COL), Hyaluronic acid (HA) crosslinked loaded with silver nanoparticles (AgNPs), Gentamicin (GENT) and AgNPs/GENT successfully prepared using freeze drying technique. Chemical evaluations for synthesized membranes were carried out using FTIR- ATR. While physical properties were evaluated through swelling and degradation percent. Antibacterial activity was evaluated against G+, G-, yeast and fungi. Finally, cytotoxicity and wound healing evaluations were carried out against skin fibroblast normal cell line, while anti-inflammatory evaluated using RAW 264.7 macrophage cell line. The three produced membrane showed physically interaction between polymer network and the loaded antibiotic. Swelling properties showed superior results for three membranes. Degradability of prepared sheets was rapidly no more than three days. Toxicity evaluations and anti-inflammatory showed superior results for all examined samples except mixed with AgNPs and Gentamicin (GENT). Antibacterial activity showed resistance to G+, G- and yeast. All prepared sheet showed safe towards cell except COL/HA/AgNPs/GENT. Wound healing studied showed efficient of both COL/HA/AgNPs and COL/HA/GENT compared to blank and mixed membrane COL/HA/AgNPs/GENT. The obtained results recommended COL/HA loaded individually either AgNPs or Gentamicin (GENT) as antibacterial and wound healing sheet rather than mixed prepared membrane.

Preparation and characterization of carboxymethyl chitosan/pullulan composite film incorporated with eugenol and its application in the preservation of chilled meat

To solve the problem of easy spoilage of chilled meat during storage, we fabricated a novel composite film using carboxymethyl chitosan (CMCS)/pullulan (Pul)/eugenol (E) by casting method. The results showed that the mechanical properties of the films were better when the CMCS/Pul ratio was 2.5/2.5. The Fourier transform infrared spectroscopy (FTIR) results showed that intermolecular hydrogen bonds were formed among E, CMCS, and Pul, which was consistent with the rheological test results. Scanning electron microscopic (SEM) images showed that eugenol was well dispersed in the CMCS/Pul matrix. The addition of eugenol significantly increased the antibacterial properties and antioxidant properties. Moreover, when 5% eugenol was added, the water vapor permeability (WVP) of the film reduced to 2.41 × 10^-11 g/m·s·Pa. Finally, the freshness of the chilled meat wrapped with the eugenol-containing composite film was prolonged, thereby offering a potential alternative to synthetic materials.

Facile fabrication of robust bilayer film loaded with chitosan active microspheres for potential multifunctional food packing

The utilization of microcarriers is an effective technique to protect and slow down the release of active ingredients, while the combination of microcarriers and film materials is an important way to expand the application scenario of active ingredients. The aim of this study was to develop a simple and facile strategy for designing a multifunctional bilayer bioactive film that combines stable mechanical properties, sustained-release characteristics for active ingredients with good antioxidant and antibacterial properties. The EGCG-loaded chitosan active microspheres were prepared by sol-gel method, and then the carboxymethyl cellulose solution containing the active microspheres was assembled onto the carboxymethyl chitosan gel substrate based on intermolecular hydrogen bonding to construct a film with a stable bilayer structure. The results indicated that the bilayer film had dense microstructure and excellent mechanical strength (37.05 MPa), and exhibited UV-blocking properties and excellent gas barrier performance. Meanwhile, the loading of active ingredients (EGCG) in the microspheres enabled the bilayer film to exhibit excellent antioxidant and antibacterial properties, and the controlled release of EGCG by the film was sustainable and showed pH responsiveness. The results of this work provide a new perspective for the design and development of bio-based active packaging film with tunable functional characteristics.

Natural bioactive formulations for biodegradable cotton eco-fabrics with antimicrobial and fire-shielding properties

In this study, eco-friendly cotton fabrics with antimicrobial and flame-retardant properties were produced using newly developed bioactive formulations. The new natural formulations combine the biocidal properties of the biopolymer (chitosan (CS)) and essential oil (thyme oil) (EO) with the flame-retardant properties of mineral fillers (silica (SiO₂), zinc oxide (ZnO), titanium dioxide (TiO₂), and hydrotalcite (LDH)). The modified cotton eco-fabrics were analyzed in terms of morphology (optical and scanning electron microscopy (SEM)), color (spectrophotometric measurements), thermal stability (thermogravimetric analysis (TGA)), biodegradability, flammability (micro-combustion calorimetry (MCC)), and antimicrobial characteristics. The antimicrobial activity of the designed eco-fabrics was determined against different kinds of microorganism (S. aureus, E. coli, P. fluorescens, B. subtilis, A. niger, C. albicans). The antibacterial effects and flammability of the materials were found to depend strongly on the compositions of the bioactive formulation. The best results were obtained for the samples of fabric coated with the formulations containing LDH and TiO₂ filler. These samples showed the highest decreases in flammability, with heat release rate (HRR) values of 168 (W/g) and 139 (W/g), respectively, compared to the reference (233 W/g). The samples also showed very good inhibition of growth against of all the studied bacteria.

Biomaterials Based on Chitosan and Its Derivatives and Their Potential in Tissue Engineering and Other Biomedical Applications-A Review

In the times of dynamically developing regenerative medicine, more and more attention is focused on the use of natural polymers. This is due to their high biocompatibility and biodegradability without the production of toxic compounds, which means that they do not hurt humans and the natural environment. Chitosan and its derivatives are polymers made most often from the shells of crustaceans and are biodegradable and biocompatible. Some of them have antibacterial or metal-chelating properties. This review article presents the development of biomaterials based on chitosan and its derivatives used in regenerative medicine, such as a dressing or graft of soft tissues or bones. Various examples of preparations based on chitosan and its derivatives in the form of gels, films, and 3D structures and crosslinking products with another polymer are discussed herein. This article summarizes the latest advances in medicine with the use of biomaterials based on chitosan and its derivatives and provides perspectives on future research activities.

Xanthan gum/oil body-microgel emulsions with enhanced transdermal absorption for accelerating wound healing

The oil body comprises lipid droplets surrounded by a surface embedded with oil body-related proteins. To form a drug delivery system, an oleosin can be fused with foreign proteins and bound to the oil body surface. Here, safflower oil bodies carrying oleosin-human epidermal growth factor (hEGF) were mixed with xanthan gum to form self-assembled polymers, referred as an oil body microgel emulsion (OBEME) without any chemical crosslinking agent. The physicochemical properties of OBEME were evaluated and compared with those of natural lipid droplets. The electrostatic interaction between xanthan gum and oil bodies prevents excessive cross-linking and forms a uniform network structure. The basic properties of OBEME were characterized by scanning electron microscopy, cryo-scanning electron microscopy, rheology, and thermogravimetric analysis. The OBEME is an interconnected network and presents a smooth surface without any pores; it remains stable at room temperature for 90 days, and is not affected by low-speed centrifugation and repeated freeze-thaw cycles as indicated by particle size, potential, and fluorescence microscopy analyses. The OBEME enlarges the skin tissue gap, enhances skin permeability, and shows a good slow-release effect in the transdermal absorption test in vivo. It demonstrates a wound healing effect; further, it regulates the inflammatory response of full-layer skin wounds in rats, as well as accelerate angiogenesis, and promote re-epithelialization and remodeling. The OBEME as a bioactive molecule-carbohydrate complex can effectively accelerate skin regeneration and has great translational potential to provide low-cost alternative wound care treatments.

Applications of Chitosan in Surgical and Post-Surgical Materials

The continuous advances in surgical procedures require continuous research regarding materials with surgical applications. Biopolymers are widely studied since they usually provide a biocompatible, biodegradable, and non-toxic material. Among them, chitosan is a promising material for the development of formulations and devices with surgical applications due to its intrinsic bacteriostatic, fungistatic, hemostatic, and analgesic properties. A wide range of products has been manufactured with this polymer, including scaffolds, sponges, hydrogels, meshes, membranes, sutures, fibers, and nanoparticles. The growing interest of researchers in the use of chitosan-based materials for tissue regeneration is obvious due to extensive research in the application of chitosan for the regeneration of bone, nervous tissue, cartilage, and soft tissues. Chitosan can serve as a substance for the administration of cell-growth promoters, as well as a support for cellular growth. Another interesting application of chitosan is hemostasis control, with remarkable results in studies comparing the use of chitosan-based dressings with traditional cotton gauzes. In addition, chitosan-based or chitosan-coated surgical materials provide the formulation with antimicrobial activity that has been highly appreciated not only in dressings but also for surgical sutures or meshes.