ABSTRACT
The role of low-pressure RF plasma in the inactivation of Escherichia coli O157, Klebsiella pneumoniae, Proteus mirabilis, and Enterobacter sakazakii using N2-O2 and SF6 gases was assessed. 1×10(9) colony-forming units (CFUs) of each bacterial isolate were placed on three polymer foils. The effects of pressure, power, distance from the source, and exposure time to plasma gases were optimized. The best conditions to inactivate the four bacteria were a 91%N2-9%O2 mixture and a 30-minute exposure time. SF6 gas was more efficient for all the tested isolates in as much as the treatment time was reduced to only three minutes. Therefore, low-pressure plasma could be used to sterilize heat and/or moisture-sensitive medical instruments.
ABSTRACT
Polyurethane catheters made of Pellethane 2363-80AE® were treated with a low temperature plasma developed for the decontamination of reusable polymer devices in hospitals. We investigated the modifications of the polymer surface by studying the topographic modifications, the chemical modifications, and their consequences on the wettability and bacterial adhesion. This study showed that plasma treatment modified the topography and grafted oxygen and nitrogen species onto the surface, resulting in an increase in the surface polarity. This effect could be correlated to the number of nitrogen atoms interacting with the surface. Moreover, this study demonstrated the significance of multiscale heterogeneities, and the complexity of industrial medical devices made from polymers. Their surface can be heterogeneous, and they contain additives that can migrate and change the surface composition.
