Vascularization of vascular endothelial growth factor and collagen I modified beta-tricalcium phosphate porous scaffolds / 中国组织工程研究

ABSTRACT

BACKGROUND:The auditory ossicle chain reconstruction is stil an important method to treat conductive deafness. Although a great variety of materials have been applied, the blood supply of otosteon after the implantation is ignored. Moreover, there is no real bone formed. OBJECTIVE:To observe the angiogenesis of vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold which is implanted into the otocyst of guinea pig. METHODS:Total y 60 guinea pigs were randomly divided into experimental group (vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold), col agen I control group (col agen I modifiedβ-tricalcium phosphate porous scaffold) and blank control group (β-tricalcium phosphate porous scaffold). The guinea pigs were executed under anesthesia at weeks 1, 2, 3, 4 respectively. The surface of scaffolds was observed by scanning electron microscopy. The angiogenesis of scaffolds were observed by hematoxylin-eosin staining and CD34 immunohistochemistry staining, and then the microvascular density was counted. The osteogenesis of the scaffolds was observed by toluidine blue staining. RESULTS AND CONCLUSION:Endothelial cel proliferation and lumen formation could be observed after 1 week in the experimental group, and the angiogenesis reach the peak after 3 weeks with traffic branches formedbetween micropores. In the other two groups, the lumen formed at 2 weeks but no traffic branches were visible. The sprouting of new blood vessels in the pores were observed more in the experimental group than the other two groups (P<0.05). The adherence and proliferation of cel s could be examined in the surface and pores of the scaffold by scanning electron microscope. After 4 weeks, the osteogenesis could be observed by toluidine blue staining, especial y in the experimental group. These findings suggest that the vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold can realize an effective vascularization in the environment of guinea pigs’ middle ear. What’s more, the scaffold also can promote bone formation.