Release of basic fibroblast growth factor from a crosslinked glycosaminoglycan hydrogel promotes wound healing

We describe synthetic extracellular matrix (sECM) hydrogel films composed of co-crosslinked thiolated derivatives of chondroitin 6-sulfate (CS) and heparin (HP) for controlled-release delivery of basic fibroblast growth factor (bFGF) to full-thickness wounds in genetically diabetic (db/db) mice. In this model for chronic wound repair, full-thickness wounds were treated with CS, CS-bFGF, or CS-HP-bFGF films. At 2 and 4 weeks postinjury, wound closure and formation of the new epidermis and dermis were determined. Both CS and CS-HP hydrogel films accelerated wound repair, even without bFGF. Addition of bFGF to CS films showed partial dose-dependent acceleration of wound repair. Importantly, addition of bFGF to co-crosslinked CS-HP sECM films showed a dramatic bFGF dose-dependent acceleration of wound healing, as well as improved dermis formation and vascularization. Compared with 27% wound closure in 2 weeks in the controls, 89% wound closure was observed for mice treated with the CS-HP-bFGF films. The synthetic CS-HP sECM films mimic the chemistry and biology of heparan sulfate proteoglycans, and may have clinical potential for topical delivery of growth factors to patients with compromised wound healing.