Abstract:Objective To investigate local application of Alendronate sodium sustained release microspheres (ASSRM) on osteoporosis and its therapeutic effect. Methods A total of 40 osteoporotic rats were randomly divided into 4 groups: group A in which rats did not receive any intervention, group B in which drugs were systemically administrated, group C in which rats received injection of blank microsphere at left femur, and group D in which drug loaded microsphere group were injected into the left of femur. Femurs were harvested 8 weeks after treatments. Bone density was measured. Bone stress was manifested by maximum load of three-point bending. Results No obvious difference in bone density and stress was observed between group C and A (P > 0.05). Rats in group B and group D experienced increased bone density and stress compared with group A (P < 0.05), while femurs in group D had improved bone density and stress when compared with that in group B (P < 0.05). Inside group D, ASSRM treated femurs exerted significant upregulation of bone density and stress when compared with contralateral right femur (P < 0.05). Conclusion Application of Alendronate sodium sustained release microspheres significantly enhances the local bone mineral density and bone stress in osteoporosis.