Role of size and shape on biofilm eradication for nitric oxide-releasing silica nanoparticles.

Journal Article (Journal Article)

Nitric oxide (NO), a reactive free radical, has proven effective in eradicating bacterial biofilms with reduced risk of fostering antibacterial resistance. Herein, we evaluated the efficacy of NO-releasing silica nanoparticles against Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus biofilms as a function of particle size and shape. Three sizes of NO-releasing silica nanoparticles (i.e., 14, 50, and 150 nm) with identical total NO release (∼0.3 μmol/mg) were utilized to study antibiofilm eradication as a function of size. To observe the role of particle shape on biofilm killing, we varied the aspect ratio of the NO-releasing silica particles from 1 to 8 while maintaining constant particle volume (∼0.02 μm(3)) and NO-release totals (∼0.7 μmol/mg). Nitric oxide-releasing particles with decreased size and increased aspect ratio were more effective against both P. aeruginosa and S. aureus biofilms, with the Gram-negative species exhibiting the greatest susceptibility to NO. To further understand the influence of these nanoparticle properties on NO-mediated antibacterial activity, we visualized intracellular NO concentrations and cell death with confocal microscopy. Smaller NO-releasing particles (14 nm) exhibited better NO delivery and enhanced bacteria killing compared to the larger (50 and 150 nm) particles. Likewise, the rod-like NO-releasing particles proved more effective than spherical particles in delivering NO and inducing greater antibacterial action throughout the biofilm.

Full Text

Duke Authors

Cited Authors

  • Slomberg, DL; Lu, Y; Broadnax, AD; Hunter, RA; Carpenter, AW; Schoenfisch, MH

Published Date

  • October 2013

Published In

Volume / Issue

  • 5 / 19

Start / End Page

  • 9322 - 9329

PubMed ID

  • 24006838

Electronic International Standard Serial Number (EISSN)

  • 1944-8252

International Standard Serial Number (ISSN)

  • 1944-8244

Digital Object Identifier (DOI)

  • 10.1021/am402618w


  • eng