Accelerated endochondral osteoinduction in the absence of bone matrix particles in a rat model system.

摘要: Abstract Ethanol-precipitated proteins obtained from demineralized rat bone powder (DBP) by 4M guanidine-HCl extraction have been shown to reproducibly induce ectopic endochondral formation when subcutaneously implanted in rats the absence of matrix particles. Histologic and biochemical analysis revealed a temporal sequence chondrocyte differentiation, calcified cartilage formation, neovascularization, osteoblast osteoclastic remodeling, hematopoietic marrow development that is complete 21 days. In contrast previous reports, these results clearly show an osteoinductive response independent presence insoluble extracellular matrix. Compared with conventional DBP implants, guanidine-extractable protein (GE) produces accelerated more robust response. Histologically, initial chondrogenic at days 6 9 greatly amplified. Alkaline phosphatase specific activity peaks day 9, several earlier than for DBP, sixfold higher. Calcium accumulation GE implants 12 fivefold greater all mineral localized within newly new bone. Osteoclasts are up ninefold abundant rapidly remodeling ossicle, making space marrow. Delivery coprecipitated inert particles was also effective although somewhat attenuated compared alone. Bony filling 4-mm defects mandibular rami elicited 10 mg followed process increased neovascularization unimplanted controls. This fraction should prove useful inducing quantities chondrocytes osteoclasts vitro study, requirements. Likewise, ethanol-precipitated alone or carrier hold promise use reconstructive surgery.