Mechanical behavior and cell response of PCL coated α-TCP foam for cancellous-type bone replacement

The mechanical behavior and cell responses of poly (ε-carpolactone) (PCL) coated α-tricalcium phosphate (α-TCP) foam were studied as an initial step for the fabrication of a cancellous-type artificial bone replacement. The α-TCP foam was obtained from sintering CaCO₃ and CaHPO₄·2H₂O at 1500 °C. It was then coated with PCL and its three dimensional fully-interconnected porous structure was found to be maintained. The coated α-TCP samples exhibited high porosity (80-85%) with large pore size (500-700 μm) that mimic the cancellous bone structure. The PCL content of the coating layer increased from 9.3±0.4 wt% to 19.0±1.3 wt% when coated with 5 wt% to 15 wt% PCL. The compressive strength improved significantly upon PCL coating. The compressive strength of α-TCP foam, 30±10 kPa, increased to 750±20 kPa when coated with 15 wt% of PCL solution. The in vitro biological evaluations indicated that MC3T3-E1 cells adhered and proliferated well on both the α-TCP and the PCL coated α-TCP foams. It was concluded that α-TCP foam upon coating with bioresorable PCL is of good potential to fabricate cancellous-type artificial bone replacement.