title: Nanoparticles and surfaces presenting antifungal, antibacterial and antiviral properties.
abstract: Here, we present new antimicrobial nanoparticles based on silica nanoparticles (SNPs) coated with a quaternary ammonium cationic surfactant, didodecyldimethylammonium bromide (DDAB). Depending on the initial concentration of DDAB, SNPs immobilize between 45 and 275 μg of DDAB per milligram of nanoparticle. For high concentrations of DDAB adsorbed to SNP, a bilayer is formed as confirmed by zeta potential measurements, thermogravimetry, and diffuse reflectance infrared Fourier transform (DRIFT) analyses. Interestingly, these nanoparticles have lower minimal inhibitory concentrations (MIC) against bacteria and fungi than soluble surfactant. The electrostatic interaction of the DDAB with the SNP is strong, since no measurable loss of antimicrobial activity was observed after suspension in aqueous solution for 60 days. We further show that the antimicrobial activity of the nanoparticle does not require the leaching of the surfactant from the surface of the NPs. The SNPs may be immobilized onto surfaces with different chemistry while maintaining their antimicrobial activity, in this case extended to a virucidal activity. The versatility, relative facility in preparation, low cost, and large antimicrobial activity of our platform makes it attractive as a coating for large surfaces.
authors.affiliation: Matera, Núcleo 4, Lote 2, Parque tecnológico de Cantanhede, 3060-197 Cantanhede, Portugal.
authors.forename: D
authors.initials: D
authors.lastname: Botequim
authors.forename: J
authors.initials: J
authors.lastname: Maia
authors.forename: M M F
authors.initials: MM
authors.lastname: Lino
authors.forename: L M F
authors.initials: LM
authors.lastname: Lopes
authors.forename: P N
authors.initials: PN
authors.lastname: Simões
authors.forename: L M
authors.initials: LM
authors.lastname: Ilharco
authors.forename: L
authors.initials: L
authors.lastname: Ferreira
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D053758:Nanoparticles / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry* / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D000998:Antiviral Agents; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; D014867:Water; C046112:didodecyldimethylammonium; D012822:Silicon Dioxide