EXPERIMENTAL STUDY ON THE REPAIR OF THE ORBITAL WALL DEFECT WITH THE TISSUE ENGINEERED BONE OF HUMAN VASCULAR ENDOTHELIAL GROWTH FACTOR GENE

Yan Huang¹, Ke Hu^2*, Xueyao Li³, Hong Li²

¹Department of Ophthalmology, the First Clinical College, Graduate School, Chongqing Medical University, Chongqing Yubei District People's Hospital;Chongqing Yubei District People's Hospital, Chongqing 400042, PR China - ²Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, PR China - ³Department of Ophthalmology, Chongqing Yubei District People's Hospital, Chongqing 401120, PR China

Objective: To analyse the effect of tissue engineering bone transduced with human vascular endothelial growth factor (VEGF) gene in repairing an orbital wall bone defect. 

Methods: Bone marrow stroma stem cells (BMSCs) were isolated into the second generation in vitro, and VEGF genetic material was transduced into BMSCs using adenoviruses. The expression of protein and the target gene were detected with western blot and real-time PCR. The cells were inoculated on coral scaffolds, and tissue engineering bone was constructed. The continuous expression of its protein was detected with ELISA in transgenic cells. Thirty adult beagle dogs were randomly divided into four groups with 15 cases in each group, for a total of 60 cases. Group A: tissue engineering bone was constructed with BMSCs containing the transgene; group B: tissue engineering bone was constructed with BMSCs without gene transfer; group C: simple coral group; group D: open group. The materials were taken at 4 weeks, 12 weeks and 24 weeks after operation. Gross observation, Micro-CT bone mineral density analysis and an immunohistochemical method were used to detect the formation of blood vessels, and histology and histomorphology were used to compare the effect of bone defect repair. 

Results: The expression of the VEGF target gene and protein was increased by western blot and real-time PCR after gene transfer. After the construction of tissue engineering bone, VEGF protein was secreted for 22 days in vitro. The number of blood vessels in group A was significantly higher than the blood vessels in group B at 4 weeks (P). The number of new blood vessels in group A and group B was much higher than that of C and D at all detection time points (P). The bone defects in the C and D group were not repaired. 

Conclusion: The effect of VEGF repair on tissue engineering was apparent, and the formation of the new bone and the new blood vessel can be promoted in the early stage.