骨形成因子添加アテロコラーゲン溶液反復注入法による骨造成術に関する実験的研究

Abstract

Bone morphogenetic protein (BMP) induces differentiation of mesenchymal-type cells into cartilage and bone in a number of species. Therefore, BMP has been investigated as an osteoinductive factor for preparation of a bone substitute. This preliminary report presents bone augmentation using repeated injection of atelocollagen (AC) solution with BMP in mice and rats. The crude BMP and bone type Ⅰ atelocollagen were prepared from fresh bovine bones. Intramuscular injection of the AC solution with crude BMP resulted in reproducible bone induction after 2 weeks. BMP activity depended on the concentration of the AC solution as a carrier, and the 0.75% AC solution with BMP induced the highest BMP activity. Repeated injection of the AC solution with BMP did not incite a significant decrease of BMP activity which suggested an immunological response inhibiting osteoinduction. The 3-consecutive-day subperiosteal injection over the rat cranium elicited significantly higher and wider deposits of bone formation than the 3-consecutive-week one after 8 weeks. Moreover, in the 3-consecutive-day injection, each injected implant unified as a mass. On the other hand, in the 3-consecutive-week injection, each induced bone deposit was individually encapsulated by fibrous connective tissues without unification. The repeated injection method of the AC solution with BMP resulted in extensive bone induction easily and reproducibly, in the consecutive-day injection. The results obtained suggest a possibility of c1inical applications of the repeated injection method of the AC solution with BMP not only for bone augmentation but also for all osseous reconstructions, considering the interval，f requency, and location of injection.