Single and coupled effects of sterilization (autoclaving and electron beam) and ageing of plasma polymer
multilayer coating on polypropylene mesh are studied. The multilayer system consists in silver nanoparticles
entrapped between two maleic anhydride plasma polymer layers and acts as a mechanosensitive
antibacterial reservoir. Tensile strength generates cracks within the plasma polymer overlayer
which might be used as diffusive channels for Agþ species. Changes in surface and bulk properties
are followed by SEM, TEM, XPS and antibacterial assays. Whilst autoclave treatment influences surface
structure unfavorably, electron beam irradiation with dose of 25 kGy does not induce surface physical or
topographical changes. However, electron beam sterilization induces changes in chemistry of the surface
causing a decrease in O/C elemental concentration ratio. The surface shows better antibacterial efficiency
towards planktonic bacteria after electron beam sterilization and more surprisingly, the combination of
electron beam sterilization and ageing has beneficial effect on final properties of the material under
stretching.