The effect of sterilization procedures on the physiochemical properties and performance of plasma polymer films

Sterilization procedures can alter the desirable characteristics brought by plasma polymerization. Different plasma-deposited functional organic coatings are prepared by plasma co-polymerization of binary gas mixtures constituted of a hydrocarbon (butadiene/ethylene) and a heteroatom containing gas (carbon dioxide/ammonia/hydrogen sulfide). These coatings are then treated by dry heating, autoclaving, ethylene oxide, UV, and gamma-ray irradiation. The physio-chemical properties and performance of the samples are evaluated by profilometry, water contact angle goniometry, XPS, and 1-h adhesion tests with U937 cells before and after sterilization. The results reveal that the changes during these sterilization processes are dependent on the type of plasma polymer and on the sterilization method. We derive recommendations on the suitability of the sterilization methods for the different coatings.