Ceragenin mediated selectivity of antimicrobial silver nanoparticles

Mark A. Hoppens, Christopher B. Sylvester, Ammar T. Qureshi, Thomas Scherr, Desiree R. Czapski, Randolph S. Duran, Paul B. Savage, Daniel Hayes

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


The understanding that common broad-spectrum antimicrobials disrupt natural microbial flora important in acquiring nutrients and preventing infection has resulted in a paradigm shift favoring more selective antimicrobials. This work explores silver nanoparticles conjugated with ceragenin, or cationic antimicrobials (CSA-SNPs), as a potential Gram-positive selective antimicrobial. Herein, CSA-SNPs are characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, and high-performance liquid chromatography-electrospray time-of-flight mass spectrometry (HPLC-ESI-TOF-MS). The antimicrobial properties are determined through minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) and time-kill studies. Spatial selectivity of the conjugate nanoparticle was evaluated using confocal imaging, MATLAB statistical analysis, and video monitored interactions between bacteria and CSA-SNPs via laser trapping techniques. Cytotoxicity was also determined by live/dead staining and flow cytometry. Average particle size, as determined through TEM analysis, and hydrodynamic diameter, as determined via DLS, are 63.5 ± 38.8 and 102.23 ± 2.3 nm, respectively. The zeta potential of the SNP before and after CSA attachment is -18.23 and -8.34 mV, respectively. MIC/MBC data suggest that CSA-SNPs are 8 times more effective against Staphylococcus aureus than SNPs alone. Furthermore, MATLAB analysis of confocal imaging found that 70% of CSA-SNPs are within 2 μm of S. aureus, whereas this percentage falls to below 40% with respect to Escherichia coli. These results are bolstered further by laser trapping experiments demonstrating selective adherence of CSA-SNPs conjugates with bacterial strains. Cytotoxicity studies of CSA-SNPs against 3T3 fibroblasts indicate 50% cell viability at 50 ppm.

Original languageEnglish (US)
Pages (from-to)13900-13908
Number of pages9
JournalACS Applied Materials and Interfaces
Issue number16
StatePublished - Aug 27 2014

All Science Journal Classification (ASJC) codes

  • General Materials Science


Dive into the research topics of 'Ceragenin mediated selectivity of antimicrobial silver nanoparticles'. Together they form a unique fingerprint.

Cite this