A multidisciplinary approach for the safety and environmental impacts assessments of nano-enabled antimicrobial water filtration membranes

Biofouling and infections are frequent in aquaculture and necessitate extensive use of antibiotics, contributing to environmental contamination and the emergence of resistant pathogens. Nanomaterials, particularly metal oxide nanoparticles, offer a promising alternative to antibiotics due to their intrinsic antimicrobial properties. This study presents a multidisciplinary evaluation of a novel nano-engineered material designed for antimicrobial applications in aquaculture: polysulfone water filtration membranes (WFMs) (obtained with and without the addition of a binding agent, polyvinyl butyral, PVB) embedded with sonochemically synthesized water-based copper oxide nanoparticles (wCuO NPs). The performance, safety and sustainability of the two product designs, compared to those of the pristine material, were assessed through antibacterial tests against Staphylococcus aureus and Escherichia coli, in vivo acute toxicity and behavioural analyses on Danio rerio (zebrafish) embryos and larvae, in vitro skin sensitization evaluation on human keratinocytes, and the life cycle assessment (LCA) methodology. The products' characterization demonstrated variable copper ion release rates influenced by material composition. wCuO NP inclusion significantly improved the antibacterial performance, with different efficacies among membranes. Toxicological assessments on zebrafish treated with membrane leachates revealed low acute toxicity in embryos, moderate developmental delays and no relevant effects on larvae behaviour, while impaired hatching was observed as a common effect for both membrane designs. The in vitro evaluation highlighted the sensitization potential of extracts from the nano-enabled membranes lacking PVB. LCA allowed identifying electricity and NP consumption in the membrane production as the main contributions to the higher environmental impacts associated with the nano-enabling manufacturing process, compared to a conventional one.