Antimicrobial activity of a nanocomposite film formed by bacterial nanocellulose and titanium dioxide

The development of materials with antimicrobial properties has increased, mainly driven by the pandemic caused by the new coronavirus SARS-CoV-2. Bacterial nanocellulose (CB) is a polysaccharide produced and secreted by certain genera of bacteria that have unique properties (high purity, biodegradability, biocompatibility, among others) for the development of new materials with special characteristics. Titanium dioxide (TiO2) is an inorganic compound industrially produced as a white and odorless powder, that intrinsically presents photo activity, high stability, and antimicrobial activity, this mainly after irradiation of ultraviolet (UV) light irradiation. Aiming to provide antimicrobial properties on nanocellulose films produced by Komagataeibacter sp., TiO2 nanoparticles were incorporated into the surface and pores of nanocellulose film discs. After, antimicrobial activity assays were carried out in a photochemical reactor to evaluate Escherichia call ATCC 8739 susceptibilities when in contact with the CB-TiO2 film discs after 15 minutes, followed by count of colony-forming units (CFU) on agar plate. Results showed an inhibition of E. coli growth of 98.5% when in contact with CB-TiO2 in the presence of UV-A and an inhibition of 68.0% in the absence of UV-A, indicating the potential use of the biocomposite for the creation of materials and surfaces with antimicrobial properties.