title: Interactions of microorganisms with polymer nanocomposite surfaces containing oxidized carbon nanotubes.
abstract: In many environmental scenarios, the fate and impact of polymer nanocomposites (PNCs) that contain carbon nanotubes (CNT/PNCs) will be influenced by their interactions with microorganisms, with implications for antimicrobial properties and the long-term persistence of PNCs. Using oxidized single-wall (O-SWCNTs) and multi-wall CNTs (O-MWCNTs), we explored the influence that CNT loading (mass fraction≤0.1%-10%) and type have on the initial interactions of Pseudomonas aeruginosa with O-CNT/poly(vinyl alcohol) (PVOH) nanocomposites containing well-dispersed O-CNTs. LIVE/DEAD staining revealed that, despite oxidation, the inclusion of O-SWCNTs or O-MWCNTs caused PNC surfaces to exhibit antimicrobial properties. The fraction of living cells deposited on both O-SWCNT and O-MWCNT/PNC surfaces decreased exponentially with increasing CNT loading, with O-SWCNTs being approximately three times more cytotoxic on a % w/w basis. Although not every contact event between attached microorganisms and CNTs led to cell death, the cytotoxicity of the CNT/PNC surfaces scaled with the total contact area that existed between the microorganisms and CNTs. However, because the antimicrobial properties of CNT/PNC surfaces require direct CNT-microbe contact, dead cells were able to shield living cells from the cytotoxic effects of CNTs, allowing biofilm formation to occur on CNT/PNCs exposed to Pseudomonas aeruginosa for longer time periods.
authors: †Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States.
authors: David G
authors: DG
authors: Goodwin
authors: †Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States.
authors: K M
authors: KM
authors: Marsh
authors: ‡Centro de Química, Instituto Venezolano de Investigaciones Cientificas (IVIC), Altos de Pipe, Caracas 1020-A, Miranda, Venezuela.
authors: I B
authors: IB
authors: Sosa
authors: §Department of Geography and Environmental Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States.
authors: J B
authors: JB
authors: Payne
authors: ∥Materials Measurement Science Division, NIST, Gaithersburg, Maryland 20899, United States.
authors: J M
authors: JM
authors: Gorham
authors: §Department of Geography and Environmental Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States.
authors: E J
authors: EJ
authors: Bouwer
authors: †Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States.
authors: D H
authors: DH
authors: Fairbrother
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry; D018441:Biofilms; D004777:Environment; D053761:Nanocomposites; D037742:Nanotubes, Carbon / Q000382:microbiology*; D010084:Oxidation-Reduction; D011550:Pseudomonas aeruginosa / Q000502:physiology*
chemical_list: D000890:Anti-Infective Agents; D037742:Nanotubes, Carbon