Osteoporosis is detrimental to the health of skeletal structure and significantly increases the risks of bone fracture. Moreover, bone regeneration is adversely impaired by increased osteoclastic activities as a result of osteoporosis. In this study, we developed a novel formulation of injectable bone cement based on calcium phosphate silicate cement (CPSC) and leuprolide acetate (LA). Several combinations of LA-CPSC bone cement were characterized and, it is found that LA could increase the setting time and compressive strength of CPSC in a concentration-dependent manner. Moreover, the in vitro results revealed that LA-CPSC was biocompatible and able to encourage the osteoblast proliferation via the mTOR signalling pathway. Furthermore, the LA-CPSC was implanted in the osteoporotic rats to evaluate its effectiveness to repair bone fractures under the osteoporotic conditions. The biomarker study and micro-CT analyses indicated that LA-CPSC could effectively reduce the osteoclast activities and promote the bone regeneration. In conclusion, our study demonstrated that LA-CPSC injectable bone cement should be a viable solution to repair bone fractures under the osteoporotic conditions.

骨质疏松症不利于骨骼结构的健康，并显着增加骨折的风险。此外，骨质疏松症导致的破骨细胞活性增加会不利地损害骨再生。在这项研究中，我们开发了一种基于磷酸钙硅酸盐水泥 (CPSC) 和醋酸亮丙瑞林 (LA) 的新型可注射骨水泥配方。对 LA-CPSC 骨水泥的几种组合进行了表征，发现 LA 可以以浓度依赖性方式增加 CPSC 的凝固时间和抗压强度。此外，体外结果表明，LA-CPSC 具有生物相容性，能够通过 mTOR 信号通路促进成骨细胞增殖。此外，将 LA-CPSC 植入骨质疏松大鼠体内，以评估其在骨质疏松条件下修复骨折的有效性。生物标志物研究和显微CT分析表明，LA-CPSC能有效降低破骨细胞活性，促进骨再生。总之，我们的研究表明，LA-CPSC 可注射骨水泥应该是在骨质疏松条件下修复骨折的可行解决方案。