Luo Xiaozhong, Yang Zhiming, Deng Li
Division of Stem Cell and Tissue Engineering, State Key laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P. R. China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2005 Jul;19(7):569-73.
To investigate the effect of tissue engineered bone with cryopreservation on healing of bone defects and to explore feasibility of cryopreservation for tissue engineered bone.
Tissue engineered bones were constructed with osteoblasts being seeded onto bio-derived materials made from fresh human bones,and they were preserved at 4 degrees C and - 196 degrees C for 3 months and 6 months respectively. They were applied to repair segmental bone defects of rabbit's radius while the tissue engineered bone without cryopreservation and bio-derived materials were brought into control groups. The experiment was divided into groups A3, A6, B3, B6, C and D (group A3: tissue engineered bones were preserved at 4 degrees C for 3 months; group A6: tissue engineered bones were preserved at 4 degrees C for 6 months; group B3:tissue engineered bones were preserved at --196 degrees C for 3 months; group B6:tissue engineered bones were preserved at - 196 degrees C for 6 months; group C: tissue engineered bones without cryopreservation; group D: bio-derived materials). Macroscopical and histological examination were done at the 2nd, 4th, 6th, 12th weeks, X-ray examination was done at the 6th, 12th weeks and biomechanics were determined at 12th weeks after operation respectively.
Macroscopical observation showed no significant differences among group A3, A6, B3, B6 and C, but less new bone formation and more obvious boundary in group D were observed. Histological observation showed more collagen and new bone around the edge of implant of group A3, A6, B3, B6 and C than group D, and histological evaluation showed significant differences between group D and other groups (P <0.05). Radiographic observation showed no absorbability of the implant cortex and less new bone formation in group D, but the unity between implant and host bone, medullary cavity reopened, disappearance of fracture line and fine bone modelling were observed in other groups at 12 weeks after operation. Biomechanics between group D and other groups showed significant differences (P< 0. 05).
Cryopreservation (4 degrees C and - 196 degrees C) were capable of preserving tissue engineered bone for long time, and tissue engineered bone with cryopreservation has significant effect on healing of bone defects. The methods fit clinical application.
探讨冻存组织工程骨对骨缺损愈合的影响，探索组织工程骨冻存的可行性。
将成骨细胞接种于新鲜人骨制成的生物衍生材料上构建组织工程骨，分别于4℃和-196℃冻存3个月和6个月。将其应用于修复兔桡骨节段性骨缺损，同时将未冻存的组织工程骨和生物衍生材料作为对照组。实验分为A3、A6、B3、B6、C和D组（A3组：组织工程骨于4℃冻存3个月；A6组：组织工程骨于4℃冻存6个月；B3组：组织工程骨于-196℃冻存3个月；B6组：组织工程骨于-196℃冻存6个月；C组：未冻存的组织工程骨；D组：生物衍生材料）。分别于术后第2、4、6、12周进行大体及组织学检查，第6、12周进行X线检查，第12周进行生物力学测定。
大体观察显示A3、A6、B3、B6和C组之间无显著差异，但D组新骨形成较少且边界更明显。组织学观察显示A3、A6、B3、B6和C组植入物边缘周围的胶原和新骨比D组多，组织学评价显示D组与其他组之间存在显著差异（P<0.05）。影像学观察显示D组植入物皮质无吸收且新骨形成较少，但术后12周其他组观察到植入物与宿主骨愈合、髓腔再通、骨折线消失及良好的骨塑形。D组与其他组之间的生物力学显示出显著差异（P<0.05）。
4℃和-196℃冻存能够长时间保存组织工程骨，冻存的组织工程骨对骨缺损愈合有显著影响。该方法适合临床应用。
