Development of zoledronic acid functionalized hydroxyapatite loaded polymeric nanoparticles for the treatment of osteoporosis

The present study formulated a hydroxyapatite (HA)-coated lipid nanoparticle loaded with zoledronic acid to treat patients with osteoporosis (OP). HA-coated zoledronic acid loaded lipid bilayer nanoparticles (HZL NPs) were prepared using methods of extrusion and precipitation. Nanosized particles were prepared with the aim of increasing gradual and prolonged drug release and inducing toxicity of osteoblasts. Cellular morphology was investigated by scanning electron microscopy, which revealed clear spherical shaped NPs similar to 200 nm in size that could treat osteopores in the bone. In addition, a typical biphasic release pattern was observed that could be attributed to the presence of drug on the outer surface as well as on the inner core of the NPs. There was sustained release behavior [38.17 +/- 2.12% (pH 7.4) and 64.2 +/- 3.75% (pH 5) at 48 h] of the drug that maintained the drug reservoir effect at the bone site. Furthermore, HZL NPs increased the cytotoxicity of HFOb 1.19 cells and increased the proportion of cells in the early (18.1 +/- 12.4%), late (28.7 +/- 3.7%) and necrotic (67.5 +/- 1.2%) phases of apoptosis. Most importantly, HZL in the lipid nanoparticle exhibited a strong affinity towards HA, further enhancing its efficacy in the treatment of OP.