Revascularization and osteogenesis during repair of bone defects with tissue-engineered bone of nano-hydroaoatite crystal/polyamide 66/rabbit osteoplast/vascular endothelial growth factor

Abstract

Objective To employ the vascular endothelial growth factor (VEGF165) gene transfected rabbbit osteoplast to combine with the porous nano-hydrxyapatite crystal (n-HA)/polyam ide 66(/PA66) so as to evaluate the osteogenesis and rapid revascularization early after repair of the rabbit radius bone defects with the tissue-engineered bone (n-HA/PA66/osteoplast/VEGF165). Methods The animal models of bilateral radius bone defects were created in 56 New Zealand white rabbits that were then randomly divided into Group A and Group B.In Group A, the animals were implanted with n-HA/PA66on the left bone defects (Group Al) and with n-HA/PA66/VEGF165 composite materials on the right bone defects (Group A2). In Group B, the animals were implanted with n-HA/PA66/osteoplast/VEGF165 composite materials on the left side (Group B1) and with n-HA/PA66/osteoplast on the right side (Group B2).Gross, digital radiography, histological sections, vessel count and scanning electron microscopy (SEM) were performed at 2, 4, 8 and 12 weeks after operation. Results The osteogenesis and revascularization in Group B1 was superior to that in the other groups at each time point, with statistical difference (P ＜0.05).The revascularization and osteogenesis in Groups B1 and B2 was far better than that in Groups A1 and A2, with no statistical difference between Group A1 and Group A2. Conclusions The new tissue-engineered bone (n-HA/PA66/osteoplast/VEGF165) has a perfect osteogenetic effect and can promote rapid revascularization and the bone healing in the early stage after repair of the bone defects. Key words: Hydroxyapatites; Vascular endothelial growth factors; Bone defect