Preparation and in vitro degradation study of the porous dual alpha/beta-tricalcium phosphate bioceramics

Abstract

The ideal bone tissue engineering scaffolds are long-cherished with the properties of suitable three-dimensional structure, controlled biodegradability and acceptable biocompatibility. Here, the porous biphasic α/β-tricalcium phosphate (α/β-TCP) bioceramics with different two phase ratios of α-tricalcium phosphate (α-TCP) and β-tricalcium phosphate (β-TCP) were successfully synthesised by heating an amorphous calcium phosphate (ACP) precursor containing pore-forming agent. The crystalline and morphological characterisation revealed that α- and β-TCP phases co-existed in the α/β-TCP bioceramics and they had interconnected pore structures with size between 200 and 500 μm. The degradation behaviours of the biphasic α/β-TCPs were also probed in physiological saline solution under static and dynamic environments for the first time. The results showed that dissolution rate of α/β-TCP bioceramics in dynamic environment was higher than that under static conditions. Compared with monophasic TCP ceramics, these porous α/β-TCP bioceramics displayed a tailored dissolution rate through tuning the proportion of each TCP phases (α and β) in the materials, and the Ca degradation concentration correlated with the circulating flow velocity. Further, the degradation profile of porous α/β-TCPs was well-described by Johnson–Mehl–Avrami (JMA) method. The porous biphasic α/β-TCP bioceramics with controllable degradation performance hold great potential to be applied in bone tissue engineering.