Polystyrene surface modification using excimer laser and radio-frequency plasma: blood compatibility evaluations

Biomaterial surface modification is an efficient method to improve and control blood component-material interactions. In the present study, two different methods (ArF excimer laser irradiation and radio-frequency (RF) plasma treatment) were applied in separate procedures to create a vast range of physicochemical characteristics on the surface of polystyrene (PS) and investigate their effects on blood compatibility of treated surfaces. Atomic force microscopy (AFM) and Fourier transmission infrared analysis were applied to study the morphology and chemical characteristics of treated samples in comparison with those of the untreated PS. Contact angle and surface tension measurements with two different solvents were used to evaluate the wettability and surface energy of the treated PS films. The effect of the physicochemical properties of the PS surface on blood compatibility was investigated using lactate dehydrogenase (LDH) method. AFM studies showed that after laser treatment, some distinctive nanostructures are created on the surface of PS. The data from contact angle measurements demonstrated that ArF excimer laser irradiation and RF plasma treatment created surfaces with a vast range of properties in the wettability point of view. The LDH results revealed that after surface modification by laser irradiation and plasma treatment, blood compatibility of PS films was enhanced. In addition, these results offered that the most blood compatible samples were those which irradiated with 5 pulses of laser and the one treated 4 minutes in oxygen plasma.