Biomimetic Hydrogel Scaffolds with Copper Peptide-Functionalized RADA16 Nanofiber Improve Wound Healing in Diabetes

Wound healing in diabetes is retarded by the dysfunctional local microenvironment. Although there are many studies using hydrogels as substitutes for natural extracellular matrices (ECMs), hydrogels that can mimic both the structure and functions of natural ECM remain a challenge. Self-assembling peptide RADA16 nanofiber has distinct advantages to provide a biomimetic extracellular matrix nanofiber structure. However, it still lacks biological cues to promote angiogenesis that is of vital significance for diabetic wound healing. With a customized copper peptide glycyl-histidyl-lysine (GHK) functionalized RADA16, an integrated approach using functionalized RADA16 nanofiber to chelate copper ion, is innovatively proposed in this present study. The acquired composite hydrogel holds the biomimetic nanofiber architecture, and exhibits promoting angiogenesis by both enhancing adhesion and proliferation of endothelial cells (EC) in vitro and neovascularization in vivo. It shows that the functionalized nanofiber scaffolds significantly accelerated wound closure, collagen deposition, and tissue remodeling both in healthy and diabetic mice. Furthermore, immunohistochemical analysis give evidence that an upregulated expression of eNOS and CD31 in the copper peptide-functionalized RADA16 treated group. It can be envisioned that this scaffold can serve as a promising dressing for diabetic wound healing.