Antibacterial characterization of biobased and eco-friendly coatings for textile functionalization: insights from the Donizetti Project.

Functionalization of textile fibers and fabrics improves their performance, increasing durability and longevity, and providing various biological activities, including antibacterial ones. The antimicrobial effect is usually obtained through the application of chemical substances, employing expensive materials with high environmental impacts, as well as thermal treatment. For this reason, in the last decade, the textile industry has focused its attention on safer and more sustainable alternatives, using vegetable-based products, often obtained from residues or by-products from the agri-food industries, which have demonstrated to be a source of bioactive compounds with biocidal activity. In this study, the antibacterial activity of polyphenols (PPs), such as rosmarinic acid (RA) and eugenol (EU), and organic acids (OAs), including lactic acid (LA), ascorbic acid (AA) and tartaric acid (TA) was assessed. Biomolecules were then used as coatings for cotton fabrics and their antimicrobial activity against two bacterial strains, Escherichia coli as Gram-negative and Staphylococcus aureus as Gram-positive was determined by ASTM E2149 standard method, under dynamic contact conditions, for 1 hour. RA, EU and functionalized textiles reached excellent bacterial reduction. LA, AA and TA have biocidal effects against E. coli and S. aureus, with a bacterial reduction ranging from 96.3% to 100%. Cotton fabrics treated with OAs (at the concentration of 10% wt) showed antibacterial activity against E. coli and S. aureus, with bacterial reduction higher than 95.5%. These promising results demonstrated the antimicrobial efficacy of plant-derived compounds both against Gram-negative and Gram-positive microorganisms, representing a safer, sustainable and eco-friendly alternative for textile functionalization, according to circular economy principles, with future applications in industrial, biomedical, environmental and energy fields.