[{"from": "human", "value": "Could you give me a brief overview of this molecule? [C][Branch1][=Branch2][P][=Branch1][C][=O][Branch1][C][O][O][P][=Branch1][C][=O][Branch1][C][O][O]"}, {"from": "gpt", "value": "The molecule is a methylene-substituted bisphosphonate. Medronic acid has affinity for and adheres to the surface of hydroxyapatite crystals in the bone matrix. This agent accumulates at sites of osteoid mineralization and can be used, complexed with radioisotopes such as technetium 99m, in bone imaging."}]