Enhanced mechanical performance and biological evaluation of a PLGA coated β-TCP composite scaffold for load-bearing applications

Porous beta-tricalcium phosphate (beta-TCP) has been used for bone repair and replacement in clinics due to its excellent biocompatibility, osteoconductivity, and biodegradability. However, the application of beta-Tcp has been limited by its brittleness. Here, we demonstrated that an interconnected porous beta-TCP scaffold infiltrated with a thin layer of poly(lactic-co-glycolic acid) (PLGA) polymer showed improved mechanical performance compared to an uncoated beta-TCP scaffold while retaining its excellent interconnectivity and biocompatibility. The infiltration of PLGA significantly increased the compressive strength of beta-TCP scaffolds from 2.90 to 4.19 MPa, bending strength from 1.46 to 2.41 MPa, and toughness from 0.17 to 1.44 MPa, while retaining an interconnected porous structure with a porosity of 80.65%. These remarkable improvements in the mechanical properties of PLGA-coated beta-TCP scaffolds are due to the combination of the systematic coating of struts, interpenetrating structural characteristics, and crack bridging. The in vitro biological evaluation demonstrated that rat bone marrow stromal cells (rBMSCs) adhered well, proliferated, and expressed alkaline phosphatase (ALP) activity on both the PLGA-coated beta-TCP and the beta-TCP. These results suggest a new strategy for fabricating interconnected macroporous scaffolds with significantly enhanced mechanical strength for potential load-bearing bone tissue regeneration. (C) 2011 Elsevier Ltd. All rights reserved.