Stable organic nitroxide radicals have been shown to exhibit similar cell biology signaling properties as the wellknown but short-lived small molecule nitric oxide, such as affecting intracellular redox states and cell proliferation behavior. Biological processes might thus be amenable to biointerfacial regulation via release of stable nitroxide molecules from coatings applied onto biomedical devices. In this study, we utilized the facile and technologically attractive process of plasma polymerization for the deposition of thin layers containing stable nitroxide radicals, using TEMPO (2,2,6,6tetramethylpiperidin-1-yl)oxyl as the "monomer" for creating a thin polymeric film. Coatings (TEMPOpps) produced under various conditions were characterized by ellipsometry, XPS, ToF-SIMS, and EPR as well as in vitro biological effects on bacteria (Staphylococcus epidermidis), fungi (Candida albicans), and human cancer cells (KG1a). TEMPOpps were compared with plasma coatings from three structurally related precursors that lack nitroxide groups. Surface characterization by XPS and ToF-SIMS confirmed the similarity of atomic composition and molecular fragments of the TEMPOpp films to the precursor molecule. Thin (241−312 nm) films were shown by EPR to contain stable nitroxide radicals, with a G-factor of 17 G typical of TEMPO. The plasma conditions modulated the density of radicals included in the films. On TEMPOpp surfaces, the microbial pathogens Staphylococcus epidermidis and Candida albicans exhibited reduced capacity to form biofilm, and fungal cells did not transition to hyphal forms. In addition, for the nonadherent human cancer cell line KG1a, we found that TEMPOpp coatings upregulated the cells' intracellular reactive oxygen species (ROS) but were not cytotoxic. Thus, we demonstrate that TEMPOpp films with nitroxide radicals possess versatile promising biological activities, such as for coating biomedical devices to prevent infections.

Nowadays, it is more important than ever to meet the increasing technical and statutory requirements and to develop new process strategies. In sheet metal forming the low consumption of oil lubrication gets an increasingly important role. The aim in sheet metal forming is to reduce the amounts of lubricants. In the long term, the future sheet metal processing should be able to completely dispense without mineral oil-containing lubricants. Two promising approaches for a dry process design are combined in this paper for the first time and the fundamental feasibility of this new hybrid technology is shown. On the one hand, a novel approach for temporary lubrication of deep-drawing processes with CO2 as a volatile medium is used. On the other hand, it is supported by the application of an additional hard coating system such as a silicon nitride (Si3N4) or tungsten doped a-C:H multilayered (Cr/CrNx/a-C:H:W/a-C:H) coating system to further reduce tool wear and wear debris of the formed sheets made of DC04 (mat. no.: 1.0338). The results show a low coefficient of friction and reduced wear. Especially for the carbon coating system, there is minor tool wear at a higher surface pressure. By means of the graphite constituent, even a smoothening of the roughness peaks can be recorded. The next step would be the implementation of this hybrid technology on a tool for deep drawing a rectangular cup.