A composite system of recombinant mussel foot proteins accelerates diabetic chronic wound healing

Diabetic chronic wounds represent a major clinical challenge characterized by sustained oxidative stress, excessive inflammation, poor angiogenesis, and high susceptibility to bacterial infection. Single-component biomaterials are unable to address the multiple pathological disorders of diabetic wound microenvironments, resulting in unsatisfactory therapeutic efficacy. Although materials inspired by mussel foot proteins (MFPs) have shown potential for wound repair, the direct application of these proteins to diabetic wound therapy remains largely unexplored. In this study, three functional mussel foot proteins (Mcfp3, Mcfp5, Mcfp6) were recombinantly expressed and assembled into a ternary protein complex Mcfps(3,5,6). An arginine/serine-modified chitosan (ASCS) hydrogel carrying Mcfps(3,5,6) was further fabricated for diabetic chronic wound therapy. In vitro results revealed that Mcfps(3,5,6) significantly promoted cell adhesion, migration, and angiogenesis, efficiently eliminated ROS, increased SOD and GSH-Px activities, and drove macrophage polarization from pro-inflammatory M1 toward anti-inflammatory M2 phenotype. The hydroxylation rate of the ternary complex reached 43.84%, much higher than that of individual proteins. The ASCS hydrogel gelled rapidly at 37°C, exhibited good biocompatibility and effective antibacterial activity. In full-thickness diabetic mouse wounds, ASCS/Mcfps(3,5,6) hydrogel markedly accelerated wound closure, with a healing rate of 98.91% at day 14. It also reduced inflammatory infiltration and ROS levels, enhanced collagen deposition, and promoted angiogenesis. Mechanistically, the composite hydrogel restored redox homeostasis, and facilitated extracellular matrix remodeling. This multifunctional recombinant protein-hydrogel system possesses antioxidant, anti-inflammatory, pro-angiogenic capacities and acts as a promising biomacromolecular platform to treat chronic diabetic wound.