Characterization and evaluation of polycaprolactone/hydroxyapatite composite scaffolds with extra surface morphology by cryogenic printing for bone tissue engineering

In this work, the polycaprolactone (PCL) scaffold with specific surface morphology was prepared by cryogenic printing technique. Biocompatible hydroxyapatite (HA) was added to the PCL matrix to enhance the surface properties and bioactivity of the scaffolds. The effects of HA on the mechanical strength and surface morphology were studied systematically. It was found that the extra surface morphology of filament enhanced the exposure of the HA particles, which induced a positive synergistic effect on surface properties. The wettability and bio-mineralization were significantly improved, and the protein adsorption capacity was 4.5 and 3.9 times than the ones of sample with 20%HA and smooth surface, respectively. Rat bone mesenchymal stem cells (rBMSCs) were used as the cell model to evaluate the cellular response to the specific surface of the scaffolds. The results showed that the scaffolds with 20-40% HA and extra surface had better proliferation ratio. The ALP assay also demonstrated that the synergistic effect was beneficial to cell osteogenic differentiation, and the ALP level was significantly higher than that of pure PCL and smooth PCL/HA composite scaffold samples at the 14th day. Therefore, the PCL/HA composite scaffold with extra surface morphology had better potential for bone tissue engineering. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).