Heparin-conjugated injectable hydrogels with sustained releasing capability for promotion of H-type vessels formation and rat femoral bone defects repair
Jianguo Wei, Dongming Duan, Yihan Jing, Shuai Huang, Jiamin Liu, Aiju Lou, Tianhua Xiao, Yapei Chen, Xia Chen, Yuwei Zeng, Song Liu, Zhao Wang, Yixi Yang, Lei Zhou, Zenghui Wu, Le Wang
Abstract
Adequate vascularization is crucial for the repair of bone defects. Platelet-derived growth factor-BB (PDGF-BB) has been shown to promote H-type vessel formation, a specialized blood vessel, strongly positive for CD31 and endomucin, coupling angiogenesis and osteogenesis. However, the lack of a controllable growth factor delivery limits its clinical application, causing certain complications associated with PDGF-BB administration. This study developed an injectable heparin-conjugated hydrogel (GHH) for controlled delivery to facilitate the effective binding of PDGF-BB and rapid vascularized bone regeneration. Herein, in vitro experiments involving the controlled release of PDGF-BB showed that the PDGF-BB-loaded GHH (GHHP) hydrogel demonstrated excellent cytocompatibility and osteogenic properties. The subcutaneous implantation model in rats revealed that the GHHP hydrogel has the potential to induce the formation of H-type blood vessels in vivo. Furthermore, the healing of distal femoral condyle defects in rat models in vivo demonstrated that GHHP could substantially promote H-type angiogenesis and effectively repair bone defects. Our injectable heparin-conjugated sustained-release PDGF-BB hydrogel has excellent angiogenic and osteogenic properties, thus providing a novel and promising solution for bone defect repair.