Enhanced Cellular Functions on Polycaprolactone Tissue Scaffolds by O2 Plasma Surface Modification

This paper reports a study of using an oxygen-based plasma modification to alter physicochemical properties of three-dimensional (3D) PCL scaffolds and to improve mouse osteoblast cells attachment, proliferation, and osteoblastic differentiation. Different plasma modification times (1, 3, and 5-min) and their effects on surface physicochemical properties were measured by contact angle measurement, surface energy calculation (Owens‐Wendth Method), surface chemistry (XPS), and the surface topography (AFM). The effect of oxygen-based plasma modification on attachment, proliferation, and osteoblastic differentiation were examined by shear flow assay, alamarBlue assay, scanning electron microscopy (SEM), and osteoblastic differentiation markers. Results of the contact angle measurement, total solid surface energy, surface chemistry, and roughness revealed that oxygen-based plasma modification increased surface hydrophilicity, total surface energy, total amount of oxygen containing groups, and the surface roughness. A positive effect of plasma modification on cell proliferation on 3D PCL scaffolds was observed at the osteoblastic differentiation stage which was evaluated by the alkaline phosphatase (ALP) activity, osteocalcin protein secretion, and calcium mineralization. The higher ALP activity and osteocalcin secretion were detected from the cells on 3-min plasma modified PCL surface compared to unmodified samples. The calcium mineralization and SEM micrographs data also showed that there was a higher mineralized matrix deposition on 3-min plasma modified PCL scaffolds compared to unmodified scaffolds. These results suggest that the 3-min plasma modification can accelerate differentiation phase of osteoblast through improving cell‐scaffold interaction.