Plasma functionalization of carbon nanowalls and its effect on attachment of fibroblast-like cells

The potential of nanostructured carbon materials to mediate the interaction with biological cells is explored herein. Carbon layers with nano-and micro-roughness, consisting of interconnected nanowalls, vertically oriented on a substrate, were synthesized on oxidized silicon by radio-frequency plasma jet assisted chemical vapour deposition. The layers were functionalized by plasmas generated in argon admixed with ammonia or nitrogen. The plasma treatments preserved the surface's nano-micro features, but have incorporated oxygen and nitrogen functional groups in various amounts, and made the hydrophobic surface highly hydrophilic. The attachment and spread of National Collection of Type Culture fibroblast-like cells in contact with the as-deposited and plasma modified nanowall layers were assessed by optical and scanning electron microscopy, and by neutral red analysis. We show that the surface chemistry plays the leading role in cell adherence to the nanostructured surface. The preferential attachment of cells on carboxy-functionalized surfaces, against nitrogen-functionalized surfaces, is noticed.