Alendronate-decorated strontium-containing bioactive glass nanoparticles with dual osteogenic and anti-osteoclastic effects for osteoporosis

Bioactive glass (BG) has emerged as a promising material for bone regeneration. In this study, strontium-doped bioactive glass nanoparticles loaded with alendronate (A-SrBG) were fabricated and characterized to evaluate their potential for bone regeneration in osteoporosis. A-SrBG nanoparticles have excellent bioactivity, inducing apatite mineralization and achieving sustained release of bioactive ions in vitro. Moreover, A-SrBG nanoparticles could promote the differentiation of osteoblasts while inhibiting the differentiation of osteoclasts by preventing RANKL-induced activation of the NF-kappa B and mevalonate pathways. A-SrBG nanoparticles could be phagocytosed into the cells and present in the cytoplasm, which could enhance the efficiency of ALN. When implanted in vivo, A-SrBG discs promoted the regeneration of new bone. The results demonstrated that the ability of A-SrBG to dually regulate both osteogenesis and osteoclastogenesis makes it a promising candidate for the reconstruction of bone defects in osteoporosis.