Therapeutical Effect of Mg/Zn/F-CaP on BMD in Ovariectomized Rats

Osteoporosis is a silently progressive disease characterized by thinning cortical bone and disorganized trabecular bone architecture. Ovariectomixed (OVX) rats are accepted models for studies on efficacy of osteoporosis therapy. The long-term goal of our study is to develop a novel biomaterial, Mg/Zn/F-CaP, for osteoporosis therapy. Objective: The specific aim of this study was to evaluate the efficacy of selected and well characterized Mg/Zn/F-CaP preparations in correcting the bone mineral deficiency noted in OVX rats. Methods: Six rats were used for each of the six experimental groups: GN (Normal), GC (sham control), G1, G2, G3 and G4. Suspensions of selected Mg/Zn/F-CaP preparations were used for G2, G3 and G4 and Zn-containing tricalcium phosphate (Zn-TCP) was used for G1. The composition of the preparations were: G1: 6.17 wt% Zn; G2(#51): 3.39 wt% Mg; 4.24 wt% Zn and 1.02 wt% F; G3 (#68)6.38 wt% Mg, 3.63 wt % Zn, and 2.17 wt% F; G4 (#76) 4.46 wt% Mg, 3.23 wt% Zn and 3.16 wt% F. The suspensions were injected in the right thighs once a week for 12 weeks. Bone mineral density (BMD) was measured by 3-dimensional X-ray computed tomography (LCT-100A, ALOKA, JAPAN) and bone strength measured using Instron-MTS (MZ-501D, MARUTO, JAPAN). Results: BMD and bone strengths of the femur from the G1, G2, G3 and G4 groups were significantly higher than those of GC. No significant difference was observed in the BMD and in the bone strengths between the left and right femurs for all groups. Conclusion: Mg/Zn/F-CaP compounds have potential use for osteoporosis therapy. [Supported by research grant no. RO1 EB 003070 from NIH/NIBIB (PI: RZ LeGeros)]