Biodegradable Sodium Alginate/Carrageenan/Cellulose Composite Hydrogel Wound Dressings Containing Herbal Extracts for Promoting Blood Coagulation and Wound Healing

Dextran-Based Antibacterial Hydrogel Dressings for Accelerating Infected Wound Healing by Reducing Inflammation Levels

Infected wounds pose challenges such as exudate management, bacterial infections, and persistent inflammation, making them a significant challenge for modern dressings. To address these issues in infected wounds more effectively, aerogel-hydrogel biphase gels based on dextran are developed. The gel introduced in this study exhibits antibacterial and anti-inflammatory properties in the process of wound therapy, contributing to accelerated wound healing. The aerogel phase exhibits exceptional water-absorption capabilities, rapidly soaking up exudate from infected wound, thereby fostering a clean and hygienic wound healing microenvironment. Concurrently, the aerogel phase is enriched with hydrogen sulfide donors. Following water absorption and the formation of the hydrogel phase, it enables the sustained release of hydrogen sulfide around the wound sites. The experiments confirm that hydrogen sulfide, by promoting M2 macrophage differentiation and reducing the levels of inflammatory factors, effectively diminishes local inflammation levels at the wound site. Furthermore, the sodium copper chlorophyllin component within the hydrogel phase demonstrates effective antibacterial properties through photodynamic antimicrobial therapy, providing a viable solution to wound infection challenges.

Cellulose-alginate hydrogels and their nanocomposites for water remediation and biomedical applications

In the last decade, both cellulose and alginate polysaccharides have been extensively utilized for the synthesis of biocompatible hydrogels because of their alluring characteristics like low cost, biodegradability, hydrophilicity, biodegradability, ease of availability and non-toxicity. The presence of abundant hydrophilic functional groups (like carboxyl and hydroxyl) on the surface of cellulose and alginate or their derivatives makes these materials promising candidates for the preparation of hydrogels with appealing structures and characteristics, leading to growing research in water treatment and biomedical fields. These two polysaccharides are typically blended together to improve hydrogels' desired qualities (mechanical strength, adsorption properties, cellulose/alginate yield). So, keeping in view their extensive applicability, in the present review article, recent advances in the development of cellulose/nanocellulose-alginate-based hydrogels and their relevance in water treatment (adsorption of dyes, heavy metals, etc.) and biomedical field (wound healing, tissue engineering, drug delivery) has been reviewed. Further, impact of other inorganic/organic additives in cellulose/nanocellulose-alginate-based hydrogels properties like contaminants adsorption, drug delivery, tissue engineering, etc., has also been studied. Moreover, the current difficulties and future prospects of nanocellulose-alginate-based hydrogels regarding their water purification and biomedical applications are also discussed at the end.

Multifunctional Oxidized Dextran Cross-Linked Alkylated Chitosan/Drug-Loaded and Silver-Doped Mesoporous Bioactive Glass Cryogel for Hemostasis of Noncompressible Wounds

Noncompressible wounds resulting from accidents and gunshots are typically associated with excessive bleeding, slow wound healing, and bacterial infection. Shape-memory cryogel presents great potential in controlling the hemorrhaging of noncompressible wounds. In this research, a shape-memory cryogel was prepared using a Schiff base reaction between alkylated chitosan (AC) and oxidized dextran (ODex) and then incorporated with a drug-laden and silver-doped mesoporous bioactive glass (MBG). Hydrophobic alkyl chains enhanced the hemostatic and antimicrobial efficiency of the chitosan, forming blood clots in the anticoagulated condition, and expanding the application scenarios of chitosan-based hemostats. The silver-doped MBG activated the endogenous coagulation pathway by releasing Ca²⁺ and prevented infection through the release of Ag⁺. In addition, the proangiogenic desferrioxamine (DFO) in the mesopores of the MBG was released gradually to promote wound healing. We demonstrated that AC/ODex/Ag-MBG DFO(AOM) cryogels exhibited excellent blood absorption capability, facilitating rapid shape recovery. It provided a higher hemostatic capacity in normal and heparin-treated rat-liver perforation-wound models than gelatin sponges and gauze. The AOM gels simultaneously promoted infiltration, angiogenesis, and tissue integration of liver parenchymal cells. Furthermore, the composite cryogel exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli. Thus, AOM gels show great promise for clinical translation in treating lethal, noncompressible bleeding and the promotion of wound healing.

Antibacterial and hemostatic polyvinyl alcohol/microcrystalline cellulose reinforced sodium alginate breathable dressing containing Euphorbia humifusa extract based on microfluidic spinning technology

Antibacterial hemostatic medical dressings have become feasible solutions in response to the challenging wound-healing process. In this study, a novel fiber-type medical dressing with excellent breathable, antibacterial, and hemostatic qualities was created using sodium alginate (SA), microcrystalline cellulose (MCC), polyvinyl alcohol (PVA), and Euphorbia humifusa Willd (EHW) based on microfluidic spinning technology, and the properties of the dressing were characterized. The orthogonal test demonstrates that PVA and MCC can enhance the mechanical properties of the fiber, which is a crucial requirement for fiber assembly to form the dressing. Moreover, the presence of EHW enhances the dressing's antibacterial and hemostatic qualities. The dressings have been proven to have potent antibacterial and hemostatic properties as well as the ability to considerably speed up wound healing and skin tissue regeneration in the in-vitro and in-vivo tests. In conclusion, this innovative fiber-type medical dressing containing SA, MCC, PVA, and EHW has enormous potential for managing wounds caused by bacteria.