Effect of Low Molecular Weight Oxidized Materials on Cell Adhesion of <scp>VUV</scp> ‐Irradiated Cyclo Olefin Polymer

ABSTRACT Many polymeric materials lack cell adhesive properties and require surface modification for cell culture use. Vacuum ultraviolet (VUV), plasma, and corona irradiation are widely used surface modification techniques. These treatments are known to cause oxidation and etching of the polymer surface, resulting in improved cell adhesion. It is also known that low molecular weight oxidized materials (LMWOMs) are formed on the polymer surface during this process. However, the effect of LMWOMs on cells has not been investigated. In this study, using X‐ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), we confirmed that removing LMWOMs from VUV‐treated cyclo‐olefin polymer (COP) surfaces reduces oxidation and increases surface roughness. This enhances fibronectin (FN) adsorption and cell adhesion. Without LMWOM removal, optimal VUV irradiation time is critical; insufficient or excessive exposure decreases FN adsorption and cell adhesion. Conversely, when LMWOMs were removed, overall adsorption improved regardless of irradiation time, with a 25% increase in adsorption observed at the optimal irradiation time. While wettability, surface topography, and functional groups have been discussed as factors that enhance cell adhesion, this study demonstrates that LMWOMs are also an important factor. This finding provides valuable insights into the optimization of polymer surfaces for cell culture use.