Plasma treatment of polycaprolactone at medium pressure

Polycaprolactone (PCL) is a biodegradable and biocompatible polymer which has acquired much attention the last few years for its potential use in biomedical applications, like tissue engineering and bone repair. Due to its hydrophobic nature, cell adhesion, proliferation and differentiation are however far less than optimal. To overcome this drawback, the surface properties of PCL need to be improved. In this work, a medium pressure dielectric barrier discharge (DBD) operating in different atmospheres (dry air, argon and helium) is employed to alter the surface properties of PCL Chemical changes on the plasma-treated surfaces are examined using contact angle measurements and XPS analysis. Results show that discharge gas can have a significant influence on the chemical composition of the PCL surfaces: air and argon plasmas introduce oxygen-containing groups, while helium plasmas incorporate both oxygen and nitrogen-containing functionalities. This latter observation can however be explained by the fact that the helium discharge operates in the glow mode. (C) 2011 Elsevier B.V. All rights reserved.