In Situ Formation of Hydrogel Wound Dressing Based on Carboxymethyl Chitin/Tannic Acid for Promoting Skin Wound Healing

Hierarchical chitin and chitosan-derived heterostructural nanocomposites: From interdisciplinary applications to a sustainable vision

Natural biopolymeric nanomaterials are highly prioritized and indispensable for industrial production and human use due to their exceptional features. In recent years, the development of bioinspired materials has rapidly advanced, driven by their outstanding qualities and versatile applications. Among these, chitin and chitosan stand out for their biodegradability, biocompatibility, and hierarchical structures, captivating researchers worldwide. In order to ameliorate the characteristics of these materials, integrating them with complementary components such as polymers, organics, and nanomaterials to create multifunctional chitinous bio-composites has become increasingly important. This review highlights recent progress in the development of these composite biomaterials, emphasizing biomimetic design, synthesis methodologies, and applications in drug delivery, cancer therapy, tissue engineering, wound healing, antimicrobial activity, food safety, natural bio-adhesives, and various industrial uses, alongside their ecological balance on Earth within a sustainable vision. Additionally, the discussion also addresses ongoing challenges and explores potential prospects for advancing these innovative biocomposites.

Construction of environmentally stable self-adhesive conductive cellulose hydrogel for electronic skin sensor via autocatalytic fast polymerization strategy at room temperature

Bio-based conductive hydrogels are catching a widespread attention in the field of flexible sensors and human-machine interface interaction. Here, an enhanced autocatalytic system constructed from dopamine-encapsulated cellulose nanofibers (DA@CNF) and Cu2+ in a glycerol-water binary solvent achieved fast auto-polymerization of hydrogels within 60 s. X-ray photoelectron spectra (XPS), UV-vis spectrum (UV), Cyclic Voltammetry (CV) and electron paramagnetic resonance (EPR) were used to characterize the autocatalytic system. The hydrogel obtained has excellent mechanical properties (strain >900 %, compressive strength >800 kPa, toughness >700 kJ/m3), reproducible adhesive properties (>10 times), excellent high and low temperature (-20-60 °C) adaptability and stability. And the excellent electrical conductivity endows the hydrogel with high strain sensitivity (GF = 5.15) over a wide strain range (400 %). The excellent overall performance ensures the stability and accuracy of the hydrogel as a flexible electronic skin for signal detection during human-computer interface interaction. This work contributes a new research strategy for the rational design and green development of biomass-based conductive hydrogel sensors.

Waste-to-resource: Extraction and transformation of aquatic biomaterials for regenerative medicine

The fisheries and aquaculture industry are known for generating substantial waste or by-products, often underutilized, or relegated to low-value purposes. However, this overlooked segment harbors a rich repository of valuable bioactive materials of which have a broad-spectrum of high-value applications. As the blue economy gains momentum and fisheries expand, sustainable exploitation of these aquatic resources is increasingly prioritized. In this review, we present a comprehensive overview of technology-enabled methods for extracting and transforming aquatic waste into valuable biomaterials and their recent advances in regenerative medicine applications, focusing on marine collagen, chitin/chitosan, calcium phosphate and bioactive-peptides. We discuss the inherent bioactive qualities of these "waste-to-resource" aquatic biomaterials and identify opportunities for their use in regenerative medicine to advance healthcare while achieving the Sustainable Development Goals.

A low-swelling alginate hydrogel with antibacterial hemostatic and radical scavenging properties for open wound healing

Development of a low-cost and biocompatible hydrogel dressing with antimicrobial, antioxidant, and low swelling properties is important for accelerating wound healing. Here, a multifunctional alginate hydrogel dressing was fabricated using the D-(+)-gluconic acidδ-lactone/CaCO3system. The addition of hyaluronic acid and tannic acid (TA) provides the alginate hydrogel with anti-reactive oxygen species (ROS), hemostatic, and pro-wound healing properties. Notably, soaking the alginate hydrogel in a poly-ϵ-lysine (EPL) aqueous solution enables the alginate hydrogel to be di-crosslinked with EPL through electrostatic interactions, forming a dense network resembling 'armor' on the surface. This simple one-step soaking strategy provides the alginate hydrogel with antibacterial and anti-swelling properties. Swelling tests demonstrated that the cross-sectional area of the fully swollen multifunctional alginate hydrogel was only 1.3 times its initial size, thus preventing excessive wound expansion caused by excessive swelling. After 5 h ofin vitrorelease, only 7% of TA was cumulatively released, indicating a distinctly slow-release behavior. Furthermore, as evidenced by the removal of 2,2-diphenyl-1-picrylhydrazyl free radicals, this integrated alginate hydrogel systems demonstrate a notable capacity to eliminate ROS. Full-thickness skin wound repair experiment and histological analysis of the healing site in mice demonstrate that the developed multifunctional alginate hydrogels have a prominent effect on extracellular matrix formation and promotion of wound closure. Overall, this study introduces a cost-effective and convenient multifunctional hydrogel dressing with high potential for clinical application in treating open wounds.