Effects of Oxygen Plasma Treatment on Parylene C and Parylene N Membrane Biocompatibility for Tissue Barrier Models

ABSTRACT Porous membranes are integral components of in vitro tissue barrier and co-culture models and their interaction with cells and tissues directly affects the performance and credibility of these models. Plasma-treated Parylene C and Parylene N are two biocompatible Parylene variants with perceived potential for use in these models but their biocompatibility and biological interactions at their interface with cells are not well understood. Here, we use a simple approach for benchtop oxygen plasma treatment and investigate the changes in cell spreading and extracellular matrix deposition as well as the changes in material surface properties. Our results support the previous findings on the persistent effects of plasma treatment on Parylene biocompatibility while showing a more pronounced improvement for Parylene C over Parylene N. It is observed that although both increased surface roughness and persistent increases in oxygen species govern the plasma-driven improvement, the changes in oxygen concentration at the interface are the dominant factor. Overall, the results of this study provide a clear picture of potential mechanisms of plasma-induced changes in synthetic polymers which have implications for their use in in vitro model systems and other BioMEMS applications.