The Effect of Damage of a Plasma-Treated Polyurethane Surface on Bacterial Adhesion

Abstract

Abstract—Elastic polyurethanes are flexible materials used in biomedical products. Plasma treatment is a promising method of surface modification. However, external deformation of the elastic substrate could damage the modified layer and provoke various undesirable consequences. In this work, two elastic polyurethanes with different stiffness have been studied. The materials were treated by plasma immersion implantation of nitrogen ions (with the energy of 1 and 3 keV). As a result, the relief and hydrophobicity of the surfaces changed such that the adhesion of both Gram-positive (Staphylococcus) and Gram-negative (Escherichia coli) bacteria decreased. Cyclic uniaxial deformation damages the treated surfaces: transverse cracks and longitudinal folds are formed. These changes increase bacterial adhesion to values that exceeding that on untreated materials. All features of the modified surfaces correlated both with the properties of original substrate and with the treatment parameters. Bacterial adhesion is affected mainly by the peculiarities of the relief structure.