Halloysite and Zn²⁺-crosslinked gelatin/polyamidoxime-based hydrogel with immunoregulatory and antibacterial...

Wound healing is a complex physiological process involving multiple stages. Prolonged bacterial infections and persistent inflammation significantly hinder the four overlapping healing stages. Therefore, the development of multifunctional composite hydrogel dressings holds significant clinical importance and promising prospects. In this study, a gelatin/polyamidoxime-based nanocomposite hydrogel (GP/Zn-VHC) were designed and fabricated by incorporating methacrylated gelatin, polyamidoxime (PAO), and curcumin-loaded vinyl-grafted halloysite nanotubes (VHC), along with the photoinitiator and zinc ions. Photoinduced radical polymerization of vinyl groups formed halloysite-crosslinked covalent gelatin hydrogel networks. Notably, the coordination crosslinking between zinc ions and PAO significantly enhanced the mechanical and antibacterial properties of the GP/Zn-VHC hydrogel, and also gave the hydrogel immunoregulatory capacity. Meanwhile, the introduction of VHC endowed the hydrogel with excellent hemostatic, antioxidant, and anti-inflammatory capabilities. Comprehensive testing showed that our multifunctional GP/Zn-VHC hydrogel greatly speeds up skin wound healing. Its beneficial effects are due to three key properties: excellent tissue adhesion, a uniform porous structure, and its ability to promote collagen deposition and tissue regeneration while polarizing macrophages to the M2 phenotype to modulate cytokine secretion. Consequently, this study provides novel insights into the application potential of high-performance nanocomposite hydrogel dressings for efficient wound healing.