Treatment of osteoporotic bone defects with carboxymethyl chitosan based biomimetic mineralized hydrogel loaded with icaritin.

Osteoporosis, a systemic bone disease marked by reduced bone mass and deteriorated microstructure, stems primarily from an imbalance between bone formation and resorption. Normally, bone remodeling maintains mass via osteoblast-mediated formation and osteoclast-mediated resorption. In osteoporosis, this balance is disrupted, causing low bone density, increased fragility, higher fracture risk, and pathological bone defects. Current treatments focus on inhibiting resorption (e.g., bisphosphonates, RANKL inhibitors) or promoting formation (e.g., PTH analogues). However, long-term anti-resorptive use risks adverse effects like jaw osteonecrosis or atypical fractures, and drug therapy alone poorly addresses bone defects. Consequently, research increasingly explores natural products (e.g., traditional medicine compounds) and biomaterials for bone regeneration, aiming for safer, more effective therapies. This experiment develops a biomimetic mineralized hydrogel for bone defect implantation. Using carboxymethyl chitosan (CMCS) as the matrix, it cross-links alendronic acid (ALN) with the natural product genipin (GNP), aiming to promote bone regeneration in osteoporotic conditions. This compound is designated ICT@CMCS/ALN.