ABSTRACT
BACKGROUND:The autologous oxygen-delivering biomimetic nanoscaffold is composited with chondrocytes in simulated microgravity to construct the active tissue-engineered bone, which not only has excel ent osteogenic potential characteristics, but also has autologous releasing oxygen, and additional y can effectively prevent early transplant failure caused by sufficient revascularization and hypoxia. OBJECTIVE:To investigate the effects of autologous oxygen-delivering biomimetic nanoscaffold composited with chondrocytes on repairing different types of temporomandibular joint condylar fractures. METHODS:Total y 30 Sprague-Dawley rats were randomly divided into control group, experimental groups 1 and 2 (n=10 per group). The autologous oxygen-delivering nano-hydroxyapatite/chitosan scaffold composited with chondrocytes were transplanted into rats with temporomandibular joint condylar longitudinal fracture in the experimental group 1 and those with temporomandibular joint condylar transverse fracture in the experimental group 2, respectively. At 1, 3 and 6 weeks after transplantation, the number of proliferating cel nuclear antigen-positive cel s was detected by immunofluorescence assay;the chondrocyte apoptosis was detected using TUNEL method, and expressions of col agen type II, Sox9 and vascular endothelial growth factor were observed by RT-PCR technology. RESULTS AND CONCLUSION:The number of proliferating cel nuclear antigen-positive cel s in the experimental groups 1 and 2 were significantly higher than that in the control group at different time points after transplantation (P<0.05). At 3 and 6 weeks after transplantation, the number of apoptotic chondrocytes in the experimental groups 1 and 2 was significantly lower than that in the control group (P<0.05);significantly higher and highest expressions of col agen type II, Sox9 and vascular endothelial growth factor were found in the experimental groups 2 and 1 compared with the control group, respectively (P<0.05). Additional y, compared with the experimental group 2, the number of proliferating cel nuclear antigen-positive cel s was significantly lower in the experimental group 1 at 3 and 6 weeks after transplantation (P<0.05);the number of apoptotic chondrocytes was significantly lower in the experimental group 1 at 3 weeks after transplantation (P<0.05). These results indicate that autologous oxygen-delivering biomimetic nanoscaffold composited with chondrocytes to repair different types of temporomandibular joint condylar fractures presents some different outcomes.