Improvement of Bone Homeostasis Imbalance in Osteoporotic Fractures by Mesoporous Silica Carrying miR-302b

miR-302b and DKK1 are two molecules related to the regulation of bone metabolism. Mesoporous silica is a potential drug carrier. This article aims to study the mechanism of mesoporous silica carrying miR-302b targeting DKK1 regulation to improve bone homeostasis imbalance in osteoporotic fractures. Mesoporous silica nanoparticles were synthesized and characterized. miR-302b was loaded into mesoporous silica to form composite nanoparticles. In vivo rat model experiments were performed to evaluate bone metabolism. X-ray examination and μCT scan were used to detect the bone content and trabecular bone status of rats. Alcian blue/hematoxylin/Orange G staining was used to observe changes in trabecular bone in the tibial metaphysis. Immunohistochemical staining showed the formation of trabecular bone in rats in each group and changes in the number of bone cells. Calcein double labeling experiment showed the bone mineralization speed of mice in each group. Pure and stable mesoporous silica nanoparticles were successfully synthesized and miR-302b was successfully loaded into the nanoparticles. The osteoporotic fracture rat model was successfully created. In vivo experimental results showed that after injecting composite nanoparticles into mice, bone density and bone strength were significantly increased and osteoporotic fractures were improved. Mesoporous silica carries miR-302b to target DKK1 regulation, which can improve bone homeostasis imbalance in osteoporotic fractures. Composite nanoparticles can inhibit the expression of DKK1, promote bone formation, and inhibit bone resorption, thereby improving bone density and bone strength.