title: Sonochemically-Produced Metal-Containing Polydopamine Nanoparticles and Their Antibacterial and Antibiofilm Activity.
abstract: A facile one-pot sonochemical synthesis of Cu-, Ag-, and hybrid Cu/Ag-based polydopamine nanoparticles (Cu-, Ag-, and Cu/Ag-PDA-NPs) and the mechanisms by which they exert antibacterial and antibiofilm activities are reported. We showed that the nanoparticles are spherical with a core-shell structure. Whereas Cu is chelated to the shell of Cu-PDA-NPs in oxidation states of +1/+2, the core of Ag-PDA-NPs is filled with elemental Ag°. Sonochemical irradiation of dopamine in the presence of both Cu(2+) and Ag(+) generates hybrid Cu/Ag-PDA-NPs, whose shells are composed of Cu-chelated PDA with Ag° in the core. The redox potential of the metals was found to be the main determinant of the location and oxidation state of the metals. Leaching studies under physiological conditions reveal a relatively fast release of Cu ions from the shell, whereas Ag leaches very slowly from the core. The metal-containing PDA-NPs are highly microbicidal and exhibit potent antibiofilm activity. The combination of both metals in Cu/Ag-PDA-NPs is especially effective against bacteria and robust biofilms, owing to the dual bactericidal mechanisms of the metals. Most importantly, both Ag- and Cu/Ag-PDA-NPs proved to be significantly more antibacterial than commercial Ag-NPs while exhibiting lower toxicity toward NIH 3T3 mouse embryonic fibroblasts. Mechanistically, the metal-containing PDA-NPs generate stable PDA-semiquinone and reactive oxygen species under physiological conditions, which contribute at least partly to the antimicrobial activity. We also demonstrated that simple treatment of surfaces with Ag-PDA-NPs converts them to antibacterial, the activity of which was preserved even after prolonged storage under ambient conditions.
authors.affiliation: Department of Chemistry, Bar-Ilan University , Ramat-Gan, 5290002, Israel.
authors.forename: Gil
authors.initials: G
authors.lastname: Yeroslavsky
authors.affiliation: Department of Chemistry, Bar-Ilan University , Ramat-Gan, 5290002, Israel.
authors.forename: Ronit
authors.initials: R
authors.lastname: Lavi
authors.forename: Abraham
authors.initials: A
authors.lastname: Alishaev
authors.affiliation: Department of Chemistry, Bar-Ilan University , Ramat-Gan, 5290002, Israel.
authors.forename: Shai
authors.initials: S
authors.lastname: Rahimipour
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D018441:Biofilms / Q000187:drug effects*; D003300:Copper / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D051379:Mice; D041681:NIH 3T3 Cells; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D011108:Polymers / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D012834:Silver / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000502:physiology; D013499:Surface Properties; D000069453:Ultrasonic Waves
chemical_list: D000900:Anti-Bacterial Agents; D007211:Indoles; D011108:Polymers; C568283:polydopamine; D012834:Silver; D003300:Copper