Abstract: PURPOSE：To establish an experimental bony tissue bank and evaluate the viability of cryopreserved human mandible, with an attempt to explore the possibilities of applying cryopreserved bone (with cryoprotectant) for reconstruction of bone defects. METHODS: Bony tissue specimens were harvested from the donors aged from 15 to 80 years old who had impacted wisdom teeth necessitating extraction in the Department of Oral Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. Piezoelectric osteotomy was applied to acquire and pretreat the specimens, which were then packed individually with cryoprotectant and programmed cryopreserved in -80℃ refrigerator by slow-rate freezing. After registration of the necessary information, experimental bony tissue bank was set up. The cells migrated from the fragments which were subjected to a prescribed freezing period of 0, 1, 6, or 12 months were observed under inverted microscopy. Cell viability was evaluated by WST-8, and real-time PCR was used to detect the mRNA expression of Runx2, ALP and OCN. Alkaline phophatase and alizarin red staining were utilized to detect the osteogenic capacity in vitro. Cell senescence was evaluated by a histochemical staining with a Senescence Detection Kit and karyotyping was performed; cell apoptosis was also evaluated. Statistical analysis was performed using SPSS 17.0 software package. RESULTS: Cells could migrate from different fragments, proliferated well with no significant difference in cell senescence, cell apoptosis and osteogenic capacity in vitro (P>0.05). CONCLUSION: Cells derived from cryopreserved bone fragments could maintain good proliferation activity and osteogenic phenotype. It is feasible to utilize the cryopreserved bone to reconstruct bone defects.

Key words: Cryopreseration, Autogenous bone, Bony tissue bank, Bone tissue engineering