[Evaluation of the effect of 3D printed HAP-GEL scaffold combined with BMSCs and HUVECs in repairing rabbit skull defect].

Purpose: To qualitatively analyze the effect of 3D printed hydroxyapatite-gel (HAP-GEL) scaffold combined with bone marrow mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cells (HUVECs) in repairing rabbit skull defect.

Methods: The third generation BMSCs and HUVECs were co-cultured with 3D printed HAP-GEL scaffold to construct tissue engineering bone. The rabbit model of skull defect was established and randomly divided into 4 groups. HAP-GEL stent, HAP-GEL stent + BMSCs and HUVECs cells were implanted respectively, and positive control (autologous bone tissue) and blank control were set up. Twelve weeks after operation, X-ray, cone-beam CT (CBCT) scan and H-E staining were performed to observe and analyze the changes of bone defect qualitatively. RESULTS：Twelve weeks after operation, imaging examination (X-ray and CBCT) showed that there was still obvious circular transmission in the blank control group, and the density was increased and the defect boundary was blurred in both HAP-GEL stent combined cell group and HAP-GEL group, among which the bone was continuous and the bone mineral density was the highest in HAP-GEL stent composite cell group, which was close to normal tissue. The results of H-E staining at twelve weeks showed that compared with the blank control group and the HAP-GEL group, the defect area of the HAP-GEL composite group was filled with new bone and bone-like tissue, the scaffold material was degraded and there was new bone formation inside the scaffold, and the bone repair effect was good, and the osteogenic effect was similar to that of the positive control group.

Conclusions: 3D printed HAP-GEL scaffold + BMSCs + HUVECs cell complex has good osteogenic ability and biocompatibility with a good effect on repairing rabbit skull defect.