A novel PHBV/HA microsphere releasing system loaded with alendronate

Microspheres of poly(β-hydroxybutyrate-co-β-hydroxyvalerate) (PHBV) incorporated with hydroxyapatite (HA) and loaded with alendronate (AL), an osteoporosis preventing drugs, were prepared by single emulsion technique. Several methods were used to evaluate this novel drug carrier microsphere system (referred as PHBV/HA–AL). Fourier transform infrared (FTIR) was used to evaluate the enwrapping of HA and the X-ray diffraction (XRD) analysis further confirmed the success. The morphology of PHBV/HA–AL microspheres was observed by scanning electron microscope (SEM), showing rough surface with HA particles enwrapped in the PHBV matrix. The in vitro drug releasing profile of PHBV/HA–AL system was investigated in a 26-day period. There is a sustained releasing pattern after a slight burst release during the first few days. Additionally, rabbit mesenchymal stem cells (MSCs) were used to evaluate the cytotoxicity of the PHBV/HA–AL composites. This controlled release system can well support the proliferation of MSCs. The novel PHBV/HA–AL controlled release system is promising for bone repair therapy.