The High Molecular Weight PTMC Enhances PLGA and Incorporates Inorganic Particles Into Composite Microsphere Scaffolds to Promote Bone Defect Repair

To address the issues of collapse-type degradation and poor toughness observed in PLGA-based bone repair scaffolds during degradation, this study blends PLGA with poly (trimethylene carbonate) (PTMC) and fabricates microsphere scaffolds through the emulsion method followed by sintering to form solid microsphere scaffolds. Additionally, to enhance the osteogenic potential of the scaffold, β-tricalcium phosphate (β-TCP) and varying amounts of titanium dioxide (TiO 2 ) are incorporated into the polymer. Performance analysis of the composite microsphere scaffolds reveals that the scaffold exhibits a continuous pore structure with a compressive modulus comparable to that of cancellous bone. After the incorporation of inorganic particles, the compressive modulus exceeded 70 MPa. In vitro degradation experiments confirm that the composite microsphere scaffold prepared by blending PTMC exhibited a degradation rate of 9.1% at week 12 while maintaining stable macroscopic morphology. Moreover, the pH at the final stage of degradation effectively mitigated the issue of acidic degradation associated with PLGA (pH = 6.32). In vitro cell experiments demonstrate that the prepared microsphere scaffolds possess good biocompatibility, and the incorporation of β-TCP and TiO 2 enhances the composite scaffold's osteogenic potential and antibacterial properties. This scaffold holds promise as a novel approach for the treatment of bone defects.