Effects of radiation on the osteoinductive activity of recombinant human bone morphogenetic protein 2 / 中华骨科杂志

ABSTRACT

Objective To study the effects of various doses of ionizing radiation on the osteoinductive activity of recombinant human bone morphogenetic protein 2 (rhBMP-2) and the role of collagen carrier. Methods BMP complex was prepared with rhBMP-2 and collagen sponge as a carrier. The osteoinductive activity of rhBMP-2 was evaluated by heterotopic bone formation. According to the conditions of gamma irradiation, the experiments were divided into 4 groups (Ⅰ) non-irradiated complex as control; (Ⅱ) irradiated complex with 15, 20, 25 or 50 kGy; (Ⅲ) irradiated carrier collagen sponge was irradiated with 50 kGy and then mixed with non-irradiated rhBMP-2; (Ⅳ) irradiated BMP only rhBMP-2 was irradiated with 25 or 50 kGy and then mixed with non-irradiated collagen sponge. The BMP complexes were implanted into thigh muscle pouches in 34 Wistar rats, respectively. All collagen mass in muscle pouches were procured two or four weeks after implantation and examined macroscopically, radiographically and histologically. Quantitative analyses of heterotopic bone formation were evaluated by histomorphometry. Results Two weeks after implantation, collagen mass procured from muscle of irradiated complexes with 15, 20, 25 kGy are almost the same with that of control in size, shape and new bone formation, which are composed with richly vascularized connective tissue and immatured woven bone, but only the quantity of new bone in the group of 25 kGy reduced significantly(P