Cytotoxicity of Ultrasmall Gold Nanoparticles on Planktonic and Biofilm Encapsulated Gram‐Positive Staphylococci. Issue 26 (25th February 2015)

• Record Type: Journal Article
• Authors: Boda, Sunil Kumar; Broda, Janine; Schiefer, Frank; Weber‐Heynemann, Josefine; Hoss, Mareike; Simon, Ulrich; Basu, Bikramjit; Jahnen‐Dechent, Willi
• Is Part Of: Small. Volume 11:Issue 26(2015)
• Page Start: 3183
• Page End: 3193
• Publication Date: 2015-02-25
• Subjects: Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201403014
• Languages: English
• ISSNs: 1613-6810

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The emergence of multidrug resistant bacteria, especially biofilm‐associated <italic>Staphylococci</italic>, urgently requires novel antimicrobial agents. The antibacterial activity of ultrasmall gold nanoparticles (AuNPs) is tested against two gram positive: <italic>S. aureus</italic> and <italic>S. epidermidis</italic> and two gram negative: <italic>Escherichia coli</italic> and <italic>Pseudomonas aeruginosa</italic> strains. Ultrasmall AuNPs with core diameters of 0.8 and 1.4 nm and a triphenylphosphine‐monosulfonate shell (Au0.8MS and Au1.4MS) both have minimum inhibitory concentration (MIC) and minimum bactericidal concentration of 25 × 10<sup>−6</sup><sc>m</sc> [Au]. Disc agar diffusion test demonstrates greater bactericidal activity of the Au0.8MS nanoparticles over Au1.4MS. In contrast, thiol‐stabilized AuNPs with a diameter of 1.9 nm (AuroVist) cause no significant toxicity in any of the bacterial strains. Ultrasmall AuNPs cause a near 5 log bacterial growth reduction in the first 5 h of exposure, and incomplete recovery after 21 h. Bacteria show marked membrane blebbing and lysis in biofilm‐associated bacteria treated with ultrasmall AuNP. Importantly, a twofold MIC dosage of Au0.8MS and Au1.4MS each cause around 80%–90% reduction in the viability of <italic>Staphylococci</italic> enveloped in biofilms. Altogether, this study demonstrates potential therapeutic activity of ultrasmall AuNPs as an effective treatment option against staphylococcal infections.</p> </abstract>