Influence of RF Power on Wettability, Morphology and Bacterial Adhesion Properties of Oxygen Plasma Treated Silicone Catheter Surfaces

Abstract

Abstract Catheterized patients often develop a secondary infection in their body due to bacterial adhesion and growth taking place on catheter surfaces. Nanoscale surface modification can alter the bacterial adhesion pattern on the catheter surface. In the present work, we have studied the interaction of oxygen plasma with silicone catheter surfaces from the perspective of variance in RF Power to induce physicochemical surface modification to reduce bacterial adhesion. Silicone catheter surfaces have been treated in low-pressure CCP-RF (Capacitively Coupled Radio Frequency) oxygen plasma at different RF powers in the range of 25 - 150 W. Obtained results convey that with an increase in RF power, the population of atomic oxygen species becomes dominant among other species. Morphological features are found to grow more significantly in amplitude as a function of RF power. Substantial oxidation of the silicone surface is observed in the form of a polar component of surface energy. Oxygen plasma-treated catheter surfaces have exhibited a gradual reduction in E-coli bacterial cell adhesion as a function of RF power with a minimum adhesion of £1%. The shelf life of plasma-induced hydrophilicity on the catheter surface has been evaluated under different storage environments like ambient air, water, artificial urine solution, and modified atmosphere packaging. This study concludes that variance in RF power is a major controlling factor for bacterial adhesion on silicone catheter surface due to the evolution of amplitude morphological parameters keeping space morphological parameters nearly unaffected in contrast to earlier reported studies of variance in plasma exposure time[1].