A novel GelMA-SPAK hydrogel with affinity-controlled release of bFGF towards wound healing

Skin injuries remain a significant challenge due to complex healing processes, which often results in delayed recovery, scarring, and impaired functionality. During the complicated wound repair, basic fibroblast growth factor (bFGF) serves as a core regulator for accelerating angiogenesis and fibroblast proliferation. However, conventional bFGF delivery systems suffer from rapid burst release and poor sustained bioavailability, severely limiting their therapeutic efficacy. Inspired by the interactions between the extracellular matrix and growth factorsin vivo, this study develops a polyanionic hydrogel system for the controlled delivery of bFGF to regulate healing processes. Considering the ionic properties of bFGF, negative 3-Sulfopropyl acrylate potassium salt (SPAK) was ultimately chosen as the affinity ligand, and SPAK could be covalently conjugated to Gelatin Methacryloyl (GelMA) network via photopolymerization. GelMA-SPAK hydrogel material exhibited well affinity-controlled release functionality, with sustained bFGF release maintained for at least 700 h. Besides, bFGF-loaded hydrogel exhibits good cell compatibility, effectively promoted wound healing, improved tissue regeneration, and facilitated vascular growth without inducing significant inflammatory reactions, which may serve as a promising candidate for future intelligent wound dressing applications.