Progress in Hydroxyapatite Nanocarriers for Targeted and Enhanced Osteoporosis Treatment: A Comprehensive Review

Osteoporosis (OP) is a metabolic condition primarily affecting older and postmenopausal women. It is characterized by decreased bone mineral density (BMD), reduced strength, and deteriorated bone microarchitecture. This drastically increases the risk of debilitating fragility fractures and chronic discomfort, severely harming quality of life. Current anti-OP medications can slow bone resorption but often fail to target bone tissue directly, resulting in significant systemic toxicity. A promising solution is nanodrug delivery designed to specifically target bones. This approach minimizes adverse effects by precisely transporting therapeutics to the skeletal site. Hydroxyapatite (HAP) is an ideal material for this purpose due to its close resemblance to human bone mineral. HAP-based nanosystems advanced treatment strategy by enhancing bone targeting, improving drug loading capacity, and optimizing release kinetics and biocompatibility. Furthermore, HAP composite scaffolds hold great promise for bone regeneration. Incorporating bioactive molecules and drugs into these composites facilitates the repair of bone defects. This local delivery method provides the necessary biological activity to directly enhance the bone regeneration process. This review explores recent advancements in HAP-based nanosystems for OP, focusing on their therapeutic mechanisms, interactions with bone tissue, clinical applications, underscoring their superior efficacy, and promising future. However, key challenges remain in translating these systems to clinical practice, including large-scale manufacturing, long-term safety evaluation, and the need for well-designed clinical studies to validate their therapeutic potential.