Bio-multifunctional alginate/chitosan/fucoidan sponges with enhanced angiogenesis and hair follicle regeneration for promoting full-thickness wound healing

Developing bio-multifunctional wound dressings with excellent hemostasis, antibacterial, anti-inflammatory, enhanced angiogenesis and hair follicle regeneration for promoting full-thickness wound healing is highly valuable in clinical application. Herein, bio-multifunctional composite sponges were prepared by coupling alginate and chitosan with fucoidan through electrostatic interaction, Ca²⁺ crosslinking, and lyophilization processes. The prepared alginate/chitosan/fucoidan (ACF) sponges display excellent elastic properties, preserving their shape even after bending and compressive strain without failure. The ACF sponge containing 10% fucoidan (ACF-1) shows better hemostatic and antibacterial performances, and significantly promotes wound closure in a rat full-thickness wounds model compared to the alginate/chitosan group and ACF sponge containing 30% fucoidan. Furthermore, the ACF-1 sponge greatly facilitates the epithelialization and the formation of collagen in the dermis, promotes the hair follicle regeneration, enhances vascularization by upregulating the protein expression of CD31, and reduces inflammation by downregulating the protein expression of TNF-α. This work suggests that ACF sponges with a certain amount of fucoidan display great potential for the treatment of full-thickness skin repair.