Antibacterial Al-doped ZnO coatings on PLA films

Antimicrobial surfaces can play a key role in many fields, like biomedical applications and food packaging, where it is fundamental to prevent clinical infections, foodborne diseases, or quality loss of food and beverages. Materials used for such kind of applications should be biocompatible or avoid harmful effects on human health. Additionally, since a wide variety of tools and components operating in contact with human tissues or foodstuff are made of plastic-based materials, it is important to investigate antibacterial surfaces applied in conjunction with eco-friendly bio-based plastics. For all these reasons, here we propose the use of novel composites made of nanostructured aluminum-doped zinc oxide antimicrobial coatings on polylactide films. Their surface topography is inspected at sub- and supra-micron length scales, and its influence on wettability and antibacterial activity is investigated, together with FTIR analysis for identification of molecular vibrations. Their strong antimicrobial performance is assessed against four different bacterial strains, and their safety is evaluated on two different human cell lines. The results here presented identify AZO-coated PLA films as very appealing eco-friendly antibacterial systems for food packaging and biomedical applications.