Technetium-99 conjugated with methylene diphosphonate (99Tc-MDP) is a novel bisphosphonate derivative without radioactivity and has been successfully used to treat arthritis in China for years. Since bisphosphonate therapy has the potential to induce bisphosphonaterelated osteonecrosis of the jaw (BRONJ), we examined whether 99Tc-MDP represents a new class of bisphosphonate for antiresorptive therapy to ameliorate estrogen deficiency-induced bone resorption with less risk of causing BRONJ. We showed that 99Tc-MDP-treated, ovariectomized (OVX) mice had significantly improved bone mineral density and trabecular bone volume in comparison to the untreated OVX group by inhibiting osteoclasts and enhancing osteogenic differentiation of bone marrow mesenchymal stem cells. To determine the potential of inducing BRONJ, 99Tc-MDP/dexamethasone (Dex) or zoledronate/Dex was administered into C57BL/6J mice via the tail vein, followed by extraction of maxillary first molars. Interestingly, 99Tc-MDP treatment showed less risk to induce osteonecrosis in the maxillary bones compared to zoledronate treatment group, partially because 99Tc-MDP neither suppressed adaptive regulatory T cells nor activated the inflammatory T-helper-producing interleukin- 17 cells. Taken together, our findings demonstrate that 99Tc-MDP therapy may be a promising approach in the treatment of osteoporosis with less risk of causing BRONJ.
All Science Journal Classification (ASJC) codes
- Endocrinology, Diabetes and Metabolism
- Orthopedics and Sports Medicine