Enhancing Osteogenesis Differentiation and In Vitro Degradation in Polymer Scaffolds with Spike-like Strontium Carbonate Microrods

Poly-(L-lactic-acid) (PLLA) has shown significant promise in the fields of orthopedics and dentistry. However, its lack of inherent osteogenic activity limits its potential for further application in bone repair and fixation. In this study, we synthesized strontium carbonate (SrCO₃) nanoparticles and incorporated them into PLLA to prepare bioactive composite scaffolds using selective laser sintering technology. The synthesized SrCO₃ particles exhibited a unique microrod morphology with spike-like structures. In vitro degradation experiments demonstrated that SrCO₃ effectively neutralized acidic byproducts and promoted the degradation of PLLA in a dose-dependent manner. Furthermore, in vitro cell culture experiments revealed that composite scaffolds containing 1-2 wt % SrCO₃ significantly enhanced the adhesion, proliferation, and osteogenic differentiation of mouse bone marrow mesenchymal stem cells compared to the PLLA scaffolds. This can be attributed to the sustained release of Sr ions from the composite scaffolds. Overall, our study elucidates the positive effects of incorporating SrCO₃ into the PLLA matrix, highlighting its potential as an alternative to the currently used PLLA implants for promoting degradation and facilitating osteogenesis.