Perspectives of nanofibrous wound dressings based on glucans and galactans - A review

Current progress of protein-based dressing for wound healing applications - A review

Protein-based wound dressings have garnered increasing interest in recent years owing to their distinct physical, chemical, and biological characteristics. The intricate molecular composition of proteins gives rise to unique characteristics, such as exceptional biocompatibility, biodegradability, and responsiveness, which contribute to the promotion of wound healing. Wound healing is an intricate and ongoing process influenced by multiple causes, and it consists of four distinct phases. Various treatments have been developed to repair different types of skin wounds, thanks to advancements in medical technology and the recognition of the diverse nature of wounds. This review has literature reviewed within the last 3-5 years-the recent progress and development of protein in wound dressings and the fundamental properties of an ideal wound dressing. Herein, the recent strides in protein-based state-of-the-art wound dressing emphasize the significant challenges and summarize future perspectives for wound healing applications.

Preparation and characterization of a polyurethane-based sponge wound dressing with a superhydrophobic layer and an antimicrobial adherent hydrogel layer

Bacterial infection poses a significant impediment in wound healing, necessitating the development of dressings with intrinsic antimicrobial properties. In this study, a multilayered wound dressing (STPU@MTAI2/AM1) was reported, comprising a surface-superhydrophobic treated polyurethane (STPU) sponge scaffold coupled with an antimicrobial hydrogel. A superhydrophobic protective outer layer was established on the hydrophilic PU sponge through the application of fluorinated zinc oxide nanoparticles (F-ZnO NPs), thereby resistance to environmental contamination and bacterial invasion. The adhesive and antimicrobial inner layer was an attached hydrogel (MTAI2/AM1) synthesized through the copolymerization of N-[2-(methacryloyloxy)ethyl]-N, N, N-trimethylammonium iodide and acrylamide, exhibits potent adherence to dermal surfaces and broad-spectrum antimicrobial actions against resilient bacterial strains and biofilm formation. STPU@MTAI2/AM1 maintained breathability and flexibility, ensuring comfort and conformity to the wound site. Biocompatibility of the multilayered dressing was demonstrated through hemocompatibility and cytocompatibility studies. The multilayered wound dressing has demonstrated the ability to promote wound healing when addressing MRSA-infected wounds. The hydrogel layer demonstrates no secondary damage when peeled off compared to commercial polyurethane sponge dressing. The STPU@MTAI2/AM1-treated wounds were nearly completely healed by day 14, with an average wound area of 12.2 ± 4.3 %, significantly lower than other groups. Furthermore, the expression of CD31 was significantly higher in the STPU@MTAI2/AM1 group compared to other groups, promoting angiogenesis in the wound and thereby contributing to wound healing. Therefore, the prepared multilayered wound dressing presents a promising therapeutic candidate for the management of infected wounds. STATEMENT OF SIGNIFICANCE: Healing of chronic wounds requires avoidance of biofouling and bacterial infection. However developing a wound dressing which is both anti-biofouling and antimicrobial is a challenge. A multilayered wound dressing with multifunction was developed. Its outer layer was designed to be superhydrophobic and thus anti-biofouling, and its inner layer was broad-spectrum antimicrobial and could inhibit biofilm formation. The multilayered wound dressing with adhesive property could easily be removed from the wound surface preventing the cause of secondary damage. The multilayered wound dressing has demonstrated good abilities to promote MRSA-infected wound healing and presents a viable treatment for MRSA-infected wound.

Drug-free and multifunctional sodium bicarbonate/hyaluronic acid hybrid dressing for synergistic healing of infected wounds

Skin wounds are susceptible to microbial infections which commonly lead to the delayed wound healing. Rapid clearance of pathogens from the wound is of great significance and importance for efficient healing of the infected wounds. Herein, we report a multifunctional hybrid dressing, which simply combines sodium bicarbonate (NaHCO3) and hyaluronic acid (HA) for the synergistic wound healing. Addition of NaHCO3 allows the hybrid dressing to have the great antibacterial and antioxidant activity, while maintaining the intrinsic skin repair function of HA. As a result, NaHCO3/HA hybrid dressing showed the great antibacterial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) pathogens, the ability to improve the fibroblasts proliferation and migration, the cell-protection capacity under H2O2-induced oxidative stress, and most importantly, the great healing efficacy for the mice wound infected by S. aureus. We further found that the epidermal regeneration, the collagen deposition and the angiogenesis were enhanced by NaHCO3/HA hybrid dressing. All these effects were NaHCO3 concentration-dependent. Since the NaHCO3/HA hybrid dressing is drug-free, easily fabricated, biocompatible, and efficient for wound healing, it may have great potentials for clinical management of infected wounds.

Functionally multifaceted alginate/curdlan/agarose-based bilayer fibro-porous dressings for addressing full-thickness diabetic wounds

Full-thickness diabetic wounds are chronic injuries characterized by bleeding, excessive exude, and prolonged inflammation. Single-layer dressings fail to address their disturbed pathophysiology. Therefore, bilayer dressings with structural and compositional differences in each layer have gained attention. We hypothesized that natural polymer (alginate, curdlan, and agarose) based bilayer dressings with inherent healing properties could effectively resolve these issues. Hence, bilayer dressings were fabricated by electrospinning curdlan/agarose/ polyvinyl alcohol blend (top layer) on an alginate/agarose/polyvinyl alcohol-based lyophilized porous (bottom) layer. Ciprofloxacin was incorporated in both layers as a potential antibacterial drug. The bilayer dressing exhibited high swelling (~1300 %), biocompatibility (>90 % with NIH 3T3 and L929 mouse fibroblasts), and hemocompatibility (hemolysis <5 %). In vitro, scratch assay revealed a faster wound closure (~ 95-100 %) than control. Inhibition zone assay revealed antibacterial activity against Staphylococcus aureus and Escherichia coli. Real-time (in vitro) gene expression experiments performed using human THP-1 macrophages exhibited a significant increase in anti-inflammatory cytokines (4.51 fold in IL-10) and a decrease in pro-inflammatory cytokines (1.42 fold in IL-6) in comparison to lipopolysaccharide. Thus, fabricated dressings with high swelling, hemostatic, immunomodulatory, and antibacterial characteristics can serve as potential multifunctional and sustainable templates for healing full-thickness diabetic wounds.

β-Glucan extracts as high-value multifunctional ingredients for skin health: A review

β-Glucans, which are naturally present in cereals, yeast, and mushrooms, have gained attention as a potential natural source for functional foods and pharmaceuticals. Due to the availability of β-glucans from several sources, different extraction methods can be employed to obtain high purity extracts that can be further modified to enhance their solubility or other biological properties. Apart from their known ability to interact with the immune system, β-glucans possess specific properties that could benefit overall skin health and prevent age-related signs, including soothing and antioxidant activities. As a result, the use of β-glucans to mitigate damage caused by environmental stressors or skin-related issues that accelerate skin aging or trigger chronic inflammation may represent a promising, natural, eco-friendly, and cost-effective approach to maintaining skin homeostasis balance. This review outlines β-glucan extraction methodologies, molecular structure, functionalization approaches, and explores skin-related benefits of β-glucans, along with an overview of related products in the market.

Production of Exopolysaccharide-Based Porous Structures for Biomedical Applications: A Review

Exopolysaccharides, obtained from microorganisms as fermentation products, are interesting candidates for biomedical applications as scaffolds: they are biocompatible, nontoxic, antimicrobial, antitumor materials. To produce exopolysaccharide-based scaffolds, sol-gel technology could be used, which ends with the removal of the liquid phase from the polymeric network (i.e., the drying step). The aim of this review is to point out the most relevant strengths and weaknesses of the different drying techniques, focusing attention on the production of exopolysaccharide-based porous structures. Among these drying processes, supercritical carbon dioxide-assisted drying is the most promising strategy to obtain dried gels to use in the biomedical field: it produces highly porous and lightweight devices with outstanding surface areas and regular microstructure and nanostructure (i.e., aerogels). As a result of the analysis carried out in the present work, it emerged that supercritical technologies should be further explored and applied to the production of exopolysaccharide-based nanostructured scaffolds. Moving research towards this direction, exopolysaccharide utilization could be intensified and extended to the production of high added-value devices.