重组人骨形态发生蛋白-7与脱钙骨基质复合物双重骨诱导作用的生物学评价

将不同剂量的重组人骨形态发生蛋白-7(rhBMP-7)与脱钙骨基质(DBM)分别复合后,植入小鼠股部内侧肌间隙,三周后取材,通过组织学检查、碱性磷酸酶(ALP)及钙含量的测定比较各组的骨诱导活性。结果显示,三组复合物均有骨组织生成,中、高剂量组可见骨小梁、板层骨和原始骨髓腔,血管和骨髓丰富;低剂量组的成骨量明显少于中、高剂量组,且新骨的成熟度低于其他两组,DBM少部分吸收;单独植入rhBMP-7组有编织骨形成;而DBM组可见成骨细胞的聚集。rhBMP-7/DBM复合组在ALP和Ca含量水平上与同等剂量的两对照组相比均有显著性差异(P<0.01),而rhBMP-7三种剂量之间均有显著性差异(P<0.01)。这充分说明DBM作为rhBMP-7的合适载体,具有缓释作用,且二者复合可起到双重骨诱导活性;而且rhBMP-7的骨诱导活性具有一定的剂量依赖性。

Histological evaluation of double osteogenic roles of rhBMP-7 combined with DBM

Three dosages of recombinant human bone morphogenetic protein-7(rhBMP-7)mixed with decalcified bone matrix(DBM) respectively, and implanted into the thigh muscles of mice for 3 weeks to evaluate their capacity to elicit bone formation. Osteoinduction was assessed by histological methods, quantitative measurement of alkaline phosphate(ALP) level and calcium content of the ectopic new bone. Three weeks after implatation, the three combined groups all showed new bone formation. Bone trabeculae, medullary cavity of bone, and lamellar bone were observed, the blood vessel and hematopoietic marrow were plenty in B and C groups; the weigh and the maturity of the new bone were higher in medium and high dose groups. DBM were partially absorbed. Fibrous bone was present in rhBMP-7 implanted group; and osteoblast collected in control group II. ALP level and calcium content were significant high in complex group than the other two control groups with the same dose respectively(P<0.01); there was significant difference in the three complex groups(P<0.01). The results showed that DBM was effective carrier for rhBMP-7,DBM can release the protein slowly, accelerate the process of bone induction, and the composite of them have double osteogenic roles; The osteoindution dependent on the dosage of rhBMP-7 to some extent.