Functional Hydrogels for Wound Healing: Functional Design, Mechanisms of Action, and Research Progress

Wound healing is a complex pathological process covering four stages: hemostasis, inflammation, proliferation, and remodeling. Traditional dry dressings (such as gauze and bandages) have poor moisture retention, easily adhere to newly formed tissues, and lack sufficient antibacterial capacity, making it difficult to meet the repair needs of complex wounds. With their highly hydrophilic biomimetic three-dimensional network structure, hydrogels can highly mimic the Extracellular Matrix (ECM) and provide an ideal scaffold for cell proliferation. Their water content as high as 80%–95% can not only build a moist microenvironment conducive to healing and reduce damage during dressing changes, but also their excellent flexibility can adapt to high-mobility parts such as joints. In addition, hydrogels have excellent functional customizability and can serve as carriers for targeted delivery of drugs and bioactive substances, realizing the paradigm shift from "passive barrier protection" to "active regulatory therapy". This paper systematically sorts out the material design strategies of wound repair hydrogels, deeply discusses their core mechanisms of action in antibacterial, hemostatic, anti-inflammatory and pro-regenerative aspects, and summarizes their application progress in typical scenarios such as acute and chronic wounds as well as burns and scalds. Finally, this paper analyzes the current insufficient mechanical properties and barriers to clinical translation, and puts forward a prospective outlook on the future development trend of multifunctional integration and intelligence.