Water Interacting with Nanostructured Plasma Polymer Films

The use of plasma coatings is highly attractive to enhance biomaterials such as sensors, scaffolds, antibacterial surfaces and others. Recent progress in the understanding of plasma deposition processes on the nanoscale regarding gas phase activation and plasma-surface interaction enables the tailored structuring of ultrathin films providing new (near-)surface properties. To this end, it is discussed how the degree of functionality and crosslinking can be adjusted during film growth. Moreover, the role of water interaction with functional plasma polymer films gained more and more interest. Bilayers composed of two different functional group-containing layers were found to affect protein adsorption depending on the thickness of the covering layer. Similarly, hydrophobic cover layers with varying film density are explored to control water intrusion. Thus, a defined volume of water can be allowed to penetrate a nanoporous base layer. This hydration effect strongly influences protein adsorption of BSA likely due to ferroelectric order of water molecules. In addition, controlled drug release from a Ag reservoir is enabled for long-term antibacterial properties combined with anti-adhesiveness ready for industrial applications.