BiInSn-PMMA composite bone cement with adjustable mechanical properties and reduced thermal damage

Traditional polymethyl methacrylate (PMMA) bone cement faces challenges, including stress shielding due to its high elastic modulus and thermal damage from polymerization exotherm. This study develops a novel BiInSn-PMMA composite bone cement that simultaneously addresses these limitations. The results demonstrate that the mechanical properties of the composite bone cement can be effectively controlled by adjusting the ratio of BiInSn powder, thus meeting the requirements of different bone tissues. The phase change characteristics of BiInSn significantly reduce thermal risk, lowering the peak temperature in surrounding tissues from 57.6 °C to 48.3 °C and shortening the duration above 47 °C from 210 s to 39 s. In addition, the introduction of BiInSn provides the composite bone cement with good radiographic visibility while exhibiting excellent cytocompatibility<i>in vitro</i>. Overall, this BiInSn-PMMA composite bone cement possesses adjustable mechanical properties, low risk of thermal damage, good radiographic visibility, and low cytotoxicity, demonstrating its potential value in bone defect repair.