RELATIONSHIP BETWEEN DEGRADATION OF β-TCP AND OSTEOGENESIS INDUCED BY rhBMP-2
Wang Dan Hu Yunyu * Zheng Changqiong ** Zhao Guangyue * Xie Kenan ** Lu Rong * Wang Jun * (Department of Orthopaedics,Affiliated Hospital,Jining Medical College,Jining 272129) ( *Institute of Orthopaedics and Traumatology of PLA, X
To determine if degradation rate of β-TCP may influence the amounts of bone formation induced by rhBMP-2. Two kinds of β-TCP/rhBMP-2 composites(β-TCP1/rhBMP-2and β-TCP2/rhBMP-2) which own different degradation rate,were fabricated by combining β-TCP1 and β-TCP2 with rhBMP-2,and implanted into the muscle pouches in the thigh of mice.Histological study,histomorphometry,assay of alkaline phosphatase and degradation amounts of two kinds of β-TCP/rhBMP-2 were performed after implantation. Both of β-TCP1/rh BMP-2 and β-TCP2/rhBMP-2 composite implants showed signs of cartilage and bone formation.The amounts of new bone were increasing with time.But the amounts of new bone in β-TCP1/rhBMP-2 implants were much greater than in β-TCP2/rhBMP-2 implants at 8-week after implantation(P0.05).The levels of ALP activity in both groups were increasing with time before 4 weeks postimplantation(P0.05),but there was no change during 4～8 weeks.Besides,biodegradation rate of β-TCP1/rhBMP-2 was higher than that of β-TCP2/rhBMP-2 at 8-week after implantation(P0.05). The degradation rate of β-TCP can influence the amounts of BMP-inducing bone formation.