The Collagen Material To Promote Angiogenesis, Growth Factor Binding

During tissue regeneration and wound repair, the vascularization of the implants is an important aspect. It could stimulate tissue regeneration, meanwhile, it is the fundament of keeping the acestoma and new tissues. In order to promote the process of angiogenesis, many angiogenesis inducers and biomaterials have been employed in tissue regeneration and wound repair. Platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF), which are angiogenesis inducers, could induce proliferation and migration of endothelial and vascular smooth muscle cell, monocytes, granulocytes, and fibroblasts, and plays an important role in tissue regeneration and wound repair. However, there exist difficulties in the clinical application of PDGF and bFGF because of their easy diffuse and the lack of effective delivery. Demineralized bone matrix(DBM), which is a I collagen-based scaffold, is one of the extensively used scaffolds for bone repair. In addition to demineralized bone matrix-induced osteogenesis and into the role of bone conduction, the porosity and connectivity of its natural and suitable porosity conducive to seed cell adhesion, migration and ingrowth of blood vessels.Therefore, we crosslink heparin which has PDGF and bFGF binding domain to the DBM(HC-DBM) for their delivery, respectively. In in vitro experiments, heparin improves the binding of growth factors to DBM. In vitro activity assay indicates that the growth factor bound to heparin-collagen could promote human fibroblasts to proliferate on collagen gel. In in vivo experiments, the growth factor bound to HC-DBM could stimulate cells to migrate into the scaffolds after implantation. Moreover, the histological analysis shows that HC-DBM could promote vascularization of the implants, and keep the stability of blood vessels. In summary, HC-DBM could prevent the diffusion of growth factors, prolong their activity, and promote the cellularization and vascularization of the scaffold.