Empa researchers have demonstrated how they can adjust process conditions to influence the properties of novel plasma polymer coatings containing silver nanoparticles. Tailor-made films can be generated through a one-step plasma process. The scientists developed these new coatings, which kill bacteria while having no negative effect on human tissue, in the frame of an EU project.
Silver ions are very efficient at killing bacteria, and in contrast to antibiotic drugs they are effective against hundreds of different bacterial strains thanks to different attacking mechanisms. This makes silver ideal as an antibacterial additive for, e.g., implants and wound dressings. The idea that "a little is good, more is better" cannot be adopted to silver in every case, since higher ion concentrations might also damage human cells and tissues. Therefore, surface coatings need to be made with a therapeutically useful range of silver.
One possible solution is offered by the novel nanostructured polymers with integrated silver nanoparticles which a team of Empa scientists led by Enrico Körner and Dirk Hegemann are developing within the frame of an EU Project called EMBEK1 ("polymer-based, multifunctional, bactericidal materials"). In the context of this research work they investigate how varying plasma conditions during deposition influence the film structure and the associated silver ion release that determines the antibacterial effectiveness. The researchers have determined the basics for "designing" tailor-made coatings with desirable properties. The results of this work have recently been published in the scientific journal Plasma Processes and Polymers ("Formation and Distribution of Silver Nanoparticles in a Functional Plasma Polymer Matrix and Related Ag+ Release Properties").