Facile synthesis of biodegradable flower-like hydroxyapatite for drug and gene delivery

Controlled synthesis of hierarchical hydroxyapatite materials is a hot research topic because of the excellent biocompatibility and bioactivity of the materials. In this study, flower-like hydroxyapatite spheres (FHAPS) were facile synthesized in one pot using Al(OH)₃ as a structure-directing agent. The prepared FHAPS comprised nanosheets possessing a uniform diameter of approximately 4 µm. Notably, the FHAPS can be degraded in solutions with a pH of 5.5 for 144 h or incubated with cells for 48 h. In addition, the FHAPS have rough surfaces, which exhibit high loading contents for the anticancer drug doxorubicin (DOX, 9.1%) and siRNA (2.0%). Thus, the FHAPS can effectively deliver DOX into drug-resistant breast cancer cells to exert an excellent killing effect compared with free DOX and transfect siRNA into tumor cells to interfere with the expression of the target protein. Taken together, this work successfully prepared FHAPS via a convenient synthesis route that shows high delivery efficiency for anticancer drugs and siRNA.