Hard Tissue Regeneration using Gene Activated Matrix

1)从人牙髓源cDNA文库中克隆BMP细胞cDNAhBMP-2和4 cDNA形成骨。脂质体法将转染hBMP-2或4 cDNA的pcDNA3转染HEK293细胞。将细胞以胶原海绵、明胶海绵、蜂窝状黏贴海绵三种支架植入小鼠皮下组织。分别于术后2、4、8周收获种植体，评估骨形成情况。结果表明，蜂窝状拼贴海绵上的细胞形成了新骨，而其他支架上的细胞没有形成骨。2)利用基因激活基质再生骨用胶原作为基因激活基质时，不能有效地将cdna转染到细胞中。然而，在基质中加入CaP颗粒提高了体内基因转染效率。将表达rhBMP-2的质粒与胶原蛋白和Cap结合移植到大鼠胫骨5mm骨缺损中。植入后6周骨缺损完全再生，形成新骨。仅10 μ g的质粒DNA就能使骨再生，比传统方法少11100。3) pglacol胶原蛋白基因激活基质是一种有用的生物材料，但其来源于动物，有传播疾病的风险。我们发现聚甘油酸是一种合成聚合物，可以代替胶原蛋白作为基质。

1)Bone Formation by the cells transfected with BMP cDNAhBMP-2 and 4 cDNAs were cloned from human dental pulp derived cDNA library. pcDNA3 transfected with hBMP-2 or 4 cDNA was transfected into HEK293 cells by lipofectin method. The cells with Three types of scaffolds, collagen sponge, gelatin spoge, and honey-combed collage sponge, were implanted into subcutaneous tissue of mice. The implants were harvested at 2, 4, 8 weeks after operation, and the bone formation were evaluated. As the results, the cells on honey-combed collage sponge formed new bone, whereas the cells on the other scaffolds did not formed bone.2)Bone Regeneration using Gene Activated MatrixcDNAs were not transfected effectively into cells when collagen was used as matrix of gene activated matrix. However, the addition of CaP granules to the matrix improved the in vivo gene transfection efficiency. The combination of the plasmid expressing rhBMP-2, collagen and Cap grafted into 5mm bone defect created in rat tibia. The bone defects were regenerated completely with new bone 6 weeks after the implantation. Only 10 ug of plasmid DNA, which was 11100 quantity compared with the conventional way, could regenerate bone.3)Gene Activated Matrix using PGLACollagen is useful biomaterial, but is derived from animal source which has risk of transmitting disease. We found that poly glicoic acid, which is synthetic polymer, could be used as the matrix instead of collagen.