Yan Mengning, Tang Tingting, Dai Kerong, Zhou Xinshe, Yue Bin, Yu Chaofeng, Lou Jueren
Department of Orthopaedics, 9th People's Hospital, Medical College of Shanghai Jiaotong University, Shanghai 200011, P. R. China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2006 Feb;20(2):98-101.
To observe effects of the direct impaction on the cell survival and the bone formation of the tissue engineered bone modified by the adenovirus mediated human bone morphogenetic protein 2 (Adv-hBMP2) gene and to verify the feasibility of the impacted grafting with it.
The marrow stromal cells (MSCs) were separated from the canine bone marrow and were cultured. MSCs were transfected with the Adv-hBMP2 gene and combined with the freeze-dried cancellous bone (FDB) to form the tissue engineered bone. Four days after the combination, the tissue engineered bone was impacted in a simulated impactor in vitro and implanted in the mouse. The cell survivals were evaluated with SEM 1 and 4 days after the combination, immediately after the impaction, and 1 and 4 days after the impaction, respectively. The bone formation and the allograft absorption were histologically evaluated respectively.
There were multiple layers of the cells and much collagen on FDB before the impaction. Immediately after the impaction, most of the cells on the direct contact area disappeared and there was much debris on the section. Some of the cells died and separated from the surface of FDB at 1 day, the number of the cells decreased but the collagen increased on the surface at 4 days. Histologically, only the fibrous tissue was found in FDB without the cells, the bone formation on FDB was even in distribution and mass in appearance before the impaction, but declined and was mainly on the periphery after the impaction in the Adv-hBMP-2 modified tissue-engineered bone.
The simulated impaction can decrease the cells survival and the bone formation of the Adv-hBMP-2 modified tissue-engineered bone. The survival cells still function well. It is feasible to use the tissue engineered bone in the impaction graft.
观察直接冲击对腺病毒介导的人骨形态发生蛋白2（Adv-hBMP2）基因修饰的组织工程骨细胞存活及骨形成的影响，并验证其冲击植入的可行性。
从犬骨髓中分离培养骨髓间充质干细胞（MSCs）。将Adv-hBMP2基因转染至MSCs并与冻干松质骨（FDB）复合形成组织工程骨。复合4天后，将组织工程骨在体外模拟冲击装置中进行冲击，然后植入小鼠体内。分别在复合后1天和4天、冲击后即刻、冲击后1天和4天用扫描电镜评估细胞存活情况。分别从组织学角度评估骨形成及异体骨吸收情况。
冲击前FDB上有多层细胞及大量胶原。冲击后即刻，直接接触区域的大部分细胞消失，切片上有大量碎屑。1天时部分细胞死亡并从FDB表面脱落，4天时细胞数量减少但表面胶原增多。组织学上，FDB中仅见无细胞的纤维组织，冲击前Adv-hBMP-2修饰的组织工程骨中FDB上的骨形成分布均匀且量多，但冲击后骨形成减少且主要位于周边。
模拟冲击可降低Adv-hBMP-2修饰的组织工程骨的细胞存活及骨形成。存活的细胞仍能良好发挥功能。将该组织工程骨用于冲击植入是可行的。
