Physicochemical Properties, In Vitro Degradation, and Biocompatibility of Calcium Phosphate Cement Incorporating Poly(lactic-co-glycolic acid) Particles with Different Morphologies: A Comparative Study

[Image: see text] Calcium phosphate cement (CPC) is one of the most promising synthetic biomaterials for bone defect repair, but its low degradation rate and the lack of macropores restrict its repair effect. Poly(lactic-co-glycolic acid) (PLGA) is commonly used as an in situ pore forming agent in CPC, and the morphology of PLGA would affect the properties of CPC. In this study, three kinds of PLGA particles with different morphologies, including dense PLGA microspheres, dense milled PLGA particles with an irregular shape, and porous PLGA microspheres, were respectively incorporated into CPC matrix. The influences of the morphology of PLGA particles on the setting time, porosity, mechanical properties, in vitro degradation, and cytocompatibility of CPC were comparatively investigated. The results showed that the CPC composites containing dense spherical and irregularly shaped PLGA particles showed proper setting time and better compressive strength, but the CPC composite incorporating porous PLGA microspheres significantly prolonged the final setting time and dramatically decreased the compressive strength of CPC. The CPC composite containing irregularly shaped PLGA particles has shown a slightly faster in vitro degradation rate than that containing dense PLGA microspheres. In addition, the CPC composites containing dense PLGA particles were beneficial for cell proliferation. Taken together, the dense PLGA particles are suitable for use as in situ pore forming agents in the CPC matrix, and meanwhile, the dense irregularly shaped PLGA particles are more easily prepared with low cost.