Behavior of phosphatidylcholine adsorption on CNx coated PTFE films

In order to expand the applicability of PTFE for artificial replacement, the CNx coatings which could influence lipid adsorption are of considerable relevance. The intention of this study is to gain first information about the influence of CNx coating on the phosphatidylcholine (PC) adsorption of PTFE. By means of ion beam assisted deposition (IBAD), the CNx films can have a strongly bond to the PTFE substrates as a wide atomic intermixed zone that is formed at the surface. The characterization of the CN structures under different bombarding conditions was carried out by Raman and SEM as well as XPS measurements. For characterizing the behavior, analysis of PC adsorption was illuminated where Fourier transform infrared spectroscopy of attenuated total internal reflection mode (ATR-FTIR) was used as principal instrument. Results point to an increase of nitrogen content and sp2/sp3 fraction under higher bombarding voltage which seems to play a dominant role for the biological characters and a dramatic restraining of lipid deposition was induced on CNx coated PTFE compared with the uncoated samples.