The fast degradation of β-TCP ceramics facilitates healing of bone defects by the combination of BMP-2 and Teriparatide

Accumulating evidence suggests that the degradation and resorption of calcium phosphate ceramics is always relatively slow, which may inhibit calcium phosphate ceramics' replacement by new bone tissues and the ultimate bone defect repair. Bone morphogenetic proteins (BMPs) and Teriparatide (PTH) are extensively applied in the treatment of bone pathologies, while their effects on the degradation of calcium phosphate ceramics is limited. In this study, we tested the effects of BMP and PTH on degradation of β-tricalcium phosphate (β-TCP) ceramics and bone formation on β-TCP in ovariectomized (OVX) rat models. After establishment of femur defect model on OVX rats, the BMP + PTH group's rats were injected Teriparatide (30 μg/kg) subcutaneous every other day, while rats of control group and group BMP were injected equal-to-group volume sterilized saline water. Twelve weeks after femur surgery, all rats were sacrificed for Micro-CT scanning and histology tests. The results showed that BMP facilitated degradation of β-TCP and new bone formation on β-TCP ceramics. And PTH showed an additional effect on degradation of β-TCP when combined with BMP. In addition, the results explained that PTH promoted the remodeling of the bone callus occurred during repair.