Up-regulated release of vascular endothelial growth factor in tissue engineered bone with implanted vascular bundles: a model of femoral defect in rabbits

Abstract

Objective To investigate whether tissue engineered bone with implanted vascular bun-dles can up-regulate release of vascular endothelial growth factor (VEGF) in models of femoral defect in rabbits.Methods Thirty-two rabbits were randomized into 2 even groups.In both groups, a segmental bone defect of 15 mm in length was made at the left femur before a tissue engineered bone was inserted into the defect.In the experimental group, a femoral vascular bundle was implanted into the tissue engineered bone.In the control group, there was no vascular implantation.At 2, 4, 8, and 12 weeks after implantation, samples were taken to determine new bone formation by histology and expression level of VEGF by immuno-histochemistry.Results The new bone formation was significantly higher in the experimental group at the end of 4, 8, and 12 weeks(P < 0.05) .The expression level of VEGF in the experimental group was also significantly higher than in the control group at all time points after operation, and the expression of VEGF peaked at 4 weeks.Conclusion Tissue engineered bone with vascular bundle implanted can up-regulate VEGF release in models of femoral defect in rabbits. Key words: Tissue engineering; Bone; Vaseularized; Bone defect; Vascular endothelialgrowth factor