Bioactive modification of cyclic olefin copolymer (COC) film surfaces by hyaluronic acid and chitosan for enhanced cell adhesion.

Cyclic olefin copolymer (COC) has recently emerged as an attractive material in biomedical fields for its high purity, excellent stability and chemical resistance, particularly in applications of microfluidic chips, prefilled syringes and bone regeneration. However, the high hydrophobicity of COC has inhibited the adhesion of cells and biological macromolecules, such as proteins, etc., significantly limiting its broader applications. In this study, we propose a new method to modify COC surfaces by sequential coating with polydopamine (PDA) followed by hyaluronic acid (HA) or O-carboxymethyl chitosan (CMC), while comparing the impacts of the positively charged HA and negatively charged CMC on protein adsorption and cell adhesion. FTIR and XPS measurements confirmed the successful modification on COC films, resulting in surfaces with highly increased hydrophilicity, anti-oxidative properties, and improved protein adsorption. Moreover, negatively charged HA, with signal transduction capabilities showed a greater effect in promoting cell adhesion. Thus, we present a straightforward strategy for enhancing the hydrophilicity of COC surfaces, offering new insights into COC modification and potential biomedical applications.