Porous calcium phosphate ceramics modified with PLGA-bioactive glass

Abstract

Porous calcium phosphate ceramics (mainly hydroxyapatite) with interconnected macropores (~ 1 mm) and micropores (~ 5 um) as well as high porosities (~ 80%) were prepared by firing polyurethane foams that were coated with calcium phosphate cement at 1200 degrees Celsius. In order to improve the mechanical properties such as compressive strength and compressive modulus and maintain the desirable bioactivity (i.e. the ability of apatite layer formation), the open micropores of the struts were infiltrated with poly(lactic-co-glycolic acid) (PLGA) to achieve an interpenetrating bioactive ceramic/ biodegradable polymer composite structure. The PLGA filled struts were further coated with a 58S bioactive glass (33wt%)-PLGA composite coating. The PLGA- bioactive glass modified porous calcium phosphate ceramics proved to be bioactive and exhibited compressive strengths up to 7.7 MPa and compressive moduli up to 3 GPa, which were comparable to those of natural spongy bones. The obtained complex porous bioactive/ biodegradable composites could be used as tissue engineering scaffolds for low-load bearing applications.