The use of targeted alpha therapy (TAT) for bone cancer is increasing each year. Among the alpha radionuclides, radium [Ra]Ra is the first one approved for bone cancer metastasis therapy. The development of novel radiopharmaceutical based on [Ra]Ra is essential to continuously increase the arsenal of new TAT drugs. In this study we have developed, characterized, and in vitro evaluated [Ra] Ra-nano-hydroxyapatite. The results showed that [Ra] Ra-nano-hydroxyapatite has a dose-response relationship for osteosarcoma cells and a safety profile for human fibroblast cells, corroborating the application as a radiopharmaceutical.