Enhancing osteoporosis treatment using a targeted, sustained-release drug delivery system based on macrocyclic...

Osteoporosis, a prevalent systemic bone metabolic disorder, primarily affects postmenopausal women and is characterized by increased bone fragility and a heightened risk of fractures. The efficacy of current osteoporosis treatments is often limited by non-specific drug targeting and undesirable off-target skeletal side effects. To address this challenge, we have developed a novel hydroxyapatite-responsive drug delivery system. This system utilizes a self-assembled p-phosphonatocalix[4]arene tetradodecyl ether (PC4A12C), engineered to specifically target and sustain the release of osteoporosis medication at sites of bone remodeling. Our focus centers on icariin (ICA), a drug known for its potent osteogenic properties and minimal adverse effects. In vitro, ICA-loaded PC4A12C (ICA@PC4A12C) demonstrated enhanced proliferation, differentiation, and mineralization in bone marrow mesenchymal stem cells (BMSCs). In vivo, ICA@PC4A12C exhibited superior efficacy in specifically targeting bone tissue, ensuring a controlled and slow release of icariin directly within the bone environment. In an osteoporosis mouse model, treatment with ICA@PC4A12C showed notable enhancement in osteogenic activity and a significant increase in bone density compared to ICA alone. These results demonstrate the potential of PC4A12C as an effective drug carrier in the development of advanced antiosteoporotic drug delivery systems.