Hydrophilic group formation and cell culturing on polystyrene Petri-dish modified by ion-assisted reaction

Polystyrene (PS) Petri-dishes were modified by an ion-assisted reaction (IAR) to improve wettability and to supply a suitable surface for cell culturing. Low energy Ar+ ions with 1000 eV were irradiated on the surface of PS in oxygen gas environment. Water contact angles of PS were not reduced much by ion irradiation without oxygen gas and had a value of 40 degrees. In the case of ion irradiation with flowing oxygen gas, however, the water contact angles were dropped significantly from 73 degrees to 19 degrees. X-ray photoelectron spectroscopy analysis showed that the hydrophilic groups were formed on the surface of PS by a chemical reaction between unstable chains induced by ion irradiation and the oxygen gas. Newly formed hydrophilic groups were identified as -(C-O)-, -(C=O)- and -(C=O)-O- bonds. The influence of the surface modification on growth of the rat pheochromocytoma (PC12) cells was investigated. The IAR-treated PS surfaces showed enhanced attachment and growth in PC12 cell culture test. (C) 2001 Elsevier Science B.V. All rights reserved.