Incorporation of ZnO/Bioactive Glass Nanoparticles into Alginate/Chitosan Composite Hydrogels for Wound Closure

Development of proper skin wound dressing is a vital step for wound repair, especially for those patients with serious skin injuries. Herein, zinc-doped bioactive glass (ZBG)/succinyl chitosan (SCS)/oxidized alginate (OAL) composite hydrogels (Gel-ZBG) have been developed as wound dressings to accelerate wound closure. Schiff-based linkages have been introduced into the composite hydrogels, which provide a humid microenvironment for the proliferation of cells on wound sites. The amino groups from SCS and Zn²⁺ released from ZBG exhibited excellent antibacterial properties to composite hydrogels, confirmed by the antibacterial tests in vitro. Si⁴⁺ and Ca²⁺ ions are essential factors that stimulate fibroblasts to secrete beneficial factors for angiogenesis and wound closure. The epidermal growth factor (EGF) was further embedded into the hydrogels to improve cell proliferation and tissue remodeling in the wound bed. Finally, the formation of granulation tissue, deposition of collagen and myofibril, the release of anti-inflammatory factors, and angiogenesis have been investigated to determine the healing mechanism of the composite hydrogels as the wound dressings.