ABSTRAKT

Surfaces of polyimide (PI) sheets were modified using 13.56-MHz radio-frequency discharges to enhance their affinity with fibroblast cells. Physico-chemical analysis of pristine and plasma-treated PI sheets showed different responses against argon (Ar), oxygen (O₂), and nitrogen (N₂) as the plasma process gases. Overall, hydrophilicity of treated PI surfaces was enhanced, and its surface free energy increased from 53 dyn/cm to at least 73 dyn/ cm. Surface roughness values also increased from 1.3 to 40.8 nm, as demonstrated by atomic force microscopy analyses. Infrared spectral analyses showed a decrease of imide functional group peak intensities on plasma exposure, corresponding to chemical surface structural changes. In addition, plasma-treated surfaces significantly increased cell adhesion and proliferation compared to pristine samples. N₂-containing plasma exhibited the greatest increase among the test gases, due to the possible inclusion of N₂-based functional groups that enhance biochemical affinity of fibroblast cells.