Synthesis of antibacterial composite coating containing nanocapsules in an atmospheric pressure plasma

Antibacterial coating is an important strategy preventing bacterial colonization and biofilm formation. One-step synthesis of nanocapsule-containing antibacterial coatings with controlled release of Ag⁺ ions was achieved in the current work by aerosol-assisted atmospheric pressure plasma deposition. The experimental parameters of deposition including the discharge power, silver nitrate concentration, aerosol flow rate, continuous and pulsed mode of operation were studied in order to analyze their effects on surface morphology and chemical composition of the coating. Formation of nanocapsules embedded in the polymeric coating was observed. A core-shell structure was found for nanocapsule with silver in the core and polymer in the shell. Antibacterial coatings on polyethylene terephthalate film were studied in terms of Ag⁺ ion release, antibacterial properties against Escherichia coli and Staphylococcus aureus, and cytotoxicity with murine fibroblasts. Two-phase release kinetics of Ag⁺ ions was observed as initially a short-term burst release followed by a long-term slow release. It was revealed that high antibacterial efficiency of the coatings deposited on polyethylene terephthalate films can be coupled with low cytotoxicity. These biocompatible antibacterial coatings are very promising in different fields including biological applications.