Bioactive bone scaffolds manufactured by 3D printing and sacrificial templating of poly(ε-caprolactone) composites as filler for bone tissue engineering

The structures of a bone scaffold play a role in cell attachment and proliferation. In the present work, a poly(epsilon-caprolactone)/hydroxyapatite/simvastatin (PCL/HA/SIM) composite with a three-dimensional (3D) hierarchical porous structure was successfully fabricated by 3D printing a polyvinyl alcohol (PVA) sacrificial template and a subsequent polymer coating step. The SEM images show that an increase in HA content in the composite significantly decreases the diameter of micropores on the composite surface. The compressive strength measurement results of the composite scaffold show that the strength of the composite scaffold is significantly superior to that of the pure PCL scaffold. Nevertheless, the enhancement of strength in the composite scaffold is not monotonous with more content of HA in the composite as the maximum strength happens for 27.3 wt% of HA. Mouse embryonic fibroblasts (3T3) cells were in vitro cultivated in pure PCL and the composites and demonstrated that more HA content facilitates the proliferation of such cells. Furthermore, an addition of 0.2 wt% of simvastatin (SIM) to the PCL/HA composite scaffold to prepare significantly promoted the proliferation and osteogenic gene expression. The present work shows a potential novel strategy to construct bone tissue engineering scaffolds and cure bone defects.