Osteosarcoma (OS) is a common aggressive bone tumor that affects both young adults and children. The prognosis for this type of cancer remains poor due to high lung metastasis rates and radiotherapy resistance. Consequently, the development of innovative strategies to prevent this type of cancer recurrence and metastasis is crucial. This study explored an OS treatment using a modified form of curcumin (CMAP) with hydroxyapatite (CMAP-HA) functionalized with folic acid (CMAP-HAF). The samples were characterized by Fourier transform infrared spectroscopy (FTIR), CHN elemental analysis, ζ-potential, and transmission electron microscopy (TEM). The results showed the successful incorporation of folic acid (FA) into the nanostructure, resulting in cytotoxic effects on osteosarcoma cells (U2OS) and adult human dermal fibroblasts (HDFa). CMAP-HAF treatment decreased cyclin E expression by 16.8 ± 2.3%. Furthermore, CMAP-HAF was internalized by 99.6% of U2OS cells, compromising plasma membrane integrity, causing necrosis, affecting cell migration and cloning formation. These findings suggest that CMAP-HAF is a promising therapeutic agent for OS treatment and offers an innovative approach to improve patient outcomes.