Application of Biodegradable PLGA-PEG-PLGA/CPC Composite Bone Cement in the Treatment of Osteoporosis

The aim of this study was to evaluate the biological activity, safety, and effectiveness of poly(lactic acid)–poly(glycolic acid)–poly(ethylene glycol)–calcium phosphate cement (PLGA-PEG-PLGA/CPC). Methods: The PLGA-PEG-PLGA/CPC composite bone cement was used for interaction with MC3T3-E1 mouse osteoblasts in vitro and its compatibility was tested using Cell Counting Kit-8 (CCK-8). Alizarin Red staining and alkaline phosphatase activity were used to detect the osteogenic properties. Twenty healthy female New Zealand rabbits were selected to establish osteoporosis models, which were randomly divided into two groups. The experimental group was treated with 30 wt.% PLGA-PEG-PLGA/CPC, while the control group was treated with polymethyl methacrylate (PMMA) bone cement. Imaging and histomorphology of the vertebral body were analyzed after 12 weeks. The distribution and degradation of bone cement were assessed using micro-computed tomography examination and hematoxylin–eosin (HE) staining. Results: In vitro, CCK-8 revealed significant proliferation of osteoblasts in the PLGA-PEG-PLGA/CPC composite bone cement. Alizarin Red staining showed that the degree of staining increased with time. Quantitative results showed that absorbance was significantly higher in this group than in the CPC group on days 7 and 14. The alkaline phosphatase activity levels on days 7 and 14 were significantly higher in the 30 wt.% PLGA-PEG-PLGA/CPC group than in the CPC group. In vivo, postoperative micro-computed tomography and histomorphology showed that the material was evenly distributed in the vertebral body and a small amount penetrated into the trabecular bone. After 12 weeks, CPC degradation and absorption and the formation of new bone matrix were observed and the formation of a callus was obvious. Conclusion: PLGA-PEG-PLGA/CPC composite bone cement has a positive effect on the treatment of osteoporosis.