Synthesis of poly(ε-caprolactone)/hydroxyapatite nanocomposites using in-situ co-precipitation

Hybrid poly(ε-caprolactone) (PCL)/hydroxyapatite(HA) nanocomposites with various HA contents (0, 10, 20, 30 wt.%) were synthesized using an in-situ co-precipitation method. All nanocomposites prepared contained elongated HA nanocrystals dispersed uniformly in the PCL matrix without severe agglomeration. The tensile strength decreased from 13.5 ± 0.4 to 10.2 ± 0.3 MPa with increasing the HA content from 0 to 30 wt.%, whereas the elastic modulus increased from 85 ± 4.2 to 183 ± 6.6 MPa. In addition, the ALP activity was increased remarkably due to the presence of bioactive HA nanocrystals within the composites. The nanocomposite containing 30 wt.% HA showed a higher elastic modulus and ALP activity than the conventional PCL/HA composite with an initial HA content of 30 wt.%. This was attributed to the nanoscale hybridization of the HA nanocrystals without significant agglomeration.