Development of a biodegradable α-TCP/PLA/nMgO composite for enhanced guided bone regeneration.

Creating and maintaining a stable osteogenic space is crucial for successful guided bone regeneration (GBR). This study aimed to develop a customizable composite material with a moderate degradation rate that provides sustained spatial support for GBR. An in situ embedding-reinforced strategy was proposed to develop a composite material consisting of alpha-tricalcium phosphate (α-TCP), polylactic acid (PLA), and nano-magnesium oxide (nMgO). The surface characteristics, thermal stability, strength, and hardness of the composites were tested. Biocompatibility, osteogenesis, and degradation rate were evaluated both in vitro and in vivo. Compared to PLA alone, the α-TCP/PLA/nMgO composite exhibited a fivefold increase in bending strength, surpassing 95.75 MPa, along with an improvement in surface hardness from 22.8 HV1 to 28.73 HV1. In vitro experiments demonstrated that α-TCP/PLA/nMgO exhibited minimal cell cytotoxicity, promoted excellent cell adhesion, and substantial induced osteogenesis in bone marrow mesenchymal stem cells (BMSCs). In vivo experiments in mice confirmed that α-TCP/PLA/nMgO displayed excellent biocompatibility comparable to antigen-extracted xenografts and had a moderate degradation rate that provided sustained spatial support. Importantly, the α-TCP/PLA/nMgO composite can be manufactured into personalized spatial supporting meshes in accordance with individual bone defects using CAD/CAM technology, making it a promising solution for precise guided bone regeneration in scenarios where addition supporting apparatus is needed.