Biofilm consists of cells surrounded by a self-produced extracellular polymeric matrix and its production is a strategy used by microorganisms to survive in the environmental conditions. Through biofilm formation the microorganisms can settle a wide variety of surfaces (such as living tissues, food processing equipment, water supply systems etc.) providing health benefits (e.g. gut microbiota) but also risks since most human microbial infections are related to bacterial biofilms, often showing high tolerance to the antibacterial drugs. To overcome the diffusion of multidrug-resistant pathogens we focused our efforts on the development of new anti-biofilm surfaces by an approach avoiding the biofilm formation without interfering with microbial life, with the aim to reduce the resistant selection. Taking into account our previous researches, concerning the identification of natural compound derivatives (p-aminosalicylic and p-aminocinnamic acids) as non-toxic anti-biofilm agents, we studied their potential application for the functionalization of silica nanoparticles to develop new anti-biofilm coatings. The synthetic process was monitored through FT-IR and Raman spectroscopy supported by XPS and TGA. The obtained nanosystem were used to coat glass coverslips, as model surfaces, that were characterized through SEM, AFM and other physical measurements. The anti-biofilm activity of the new material was tested against P. aeruginosa, as model for Gram negative bacteria, and the promising results will be presented.

Arianna Gelain is an Assistant Professor at the University of Milan, Faculty of Pharmacy. She graduated in Pharmaceutical Chemistry and Technology and obtained a Ph.D. in Medicinal Chemistry at the University of Milan. Her scientific activity concerns the design, synthesis, and related structure-activity relationship studies of novel small molecules as signaling pathway modulators (in particular STAT3 inhibitors) and potential antimicrobial (antitubercular, anti-biofilm, and antimalarial) agents. She is the author and co-author of 60 scientific publications in peer-reviewed and SCOPUS-indexed international journals, one chapter book, and over 60 contributions (oral and poster communications) presented at national and international congresses.