The experimental Study for the Production of the Ectopic Bone Formation with Vascularized Flap

点击翻译按钮获取中文摘要

We have tried the similar experiment as last year. It is that a small-vascularized muscle flap was put on the collagen sheet including hBMP-2 cDNA in the lumen of silicon mold using rat model. We successes an excellent method, because that we need not consider unexpected systemic side effects due to the diffusion of BMP, that we prevent locally high concentration of BMP from distribution and/or leaking, and that it has definite size, shape by itself. And it is possible to produce the ideal bone shape by changing the shape of lumen of the mold of silicon. But, we are sorry that the muscle flap using direct delivery system of plasmid DNA had caused necrosis. We could not get success, although we tried various kinds the buffer and the carrier etc. We induced naked DNA into cultured cell line in vitro before subcutaneous ectopic bone formation assay in opposition. This time some small bone was created.On the one hand, we tried also the direct application of the naked plasmid. We installed plasmid vector containing hBMP-2cDNA that was included in GAM (Gene Activates Matrix) into bone deficiency in the tibia of rat with the calcium. The groups in which calcium phosphate is not included were prepared as a control. As a result, in the group that used GAM with the calcium phosphate, the bone bridge was observed Radiologcally 4 weeks later. Moreover complete bone formation was verified 6 weeks later. In addition, GAM without calcium phosphate creates less extent of bone formation. As negative control, in only the collagen, or in the plasmid that has not been installed hBMP-2cDNA, bone formation was not observed. It was thought that the efficiency of gene introduction in this new system rises clearly in comparison with GAM previously used.