This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.105.061895v1 90/2/619    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zharov, V. P. Articles by Smeltzer, M. S. Search for Related Content PubMed PubMed Citation Articles by Zharov, V. P. Articles by Smeltzer, M. S.

Photothermal Nanotherapeutics and Nanodiagnostics for Selective Killing of Bacteria Targeted with Gold Nanoparticles

Vladimir P. Zharov ^*, Kelly E. Mercer , Elena N. Galitovskaya ^* and Mark S. Smeltzer 

^* Philips Classic Laser Laboratories, and Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas

Correspondence: Address reprint requests to Vladimir P. Zharov, PhD, Tel.: 501-603-1213; Fax: 501-686-8029; E-mail: zharovvladimirp{at}uams.edu.

We describe a new method for selective laser killing of bacteria targeted with light-absorbing gold nanoparticles conjugated with specific antibodies. The multifunctional photothermal (PT) microscope/spectrometer provides a real-time assessment of this new therapeutic intervention. In this integrated system, strong laser-induced overheating effects accompanied by the bubble-formation phenomena around clustered gold nanoparticles are the main cause of bacterial damage. PT imaging and time-resolved monitoring of the integrated PT responses assessed these effects. Specifically, we used this technology for selective killing of the Gram-positive bacterium Staphylococcus aureus by targeting the bacterial surface using 10-, 20-, and 40-nm gold particles conjugated with anti-protein A antibodies. Labeled bacteria were irradiated with focused laser pulses (420–570 nm, 12 ns, 0.1–5 J/cm², 100 pulses), and laser-induced bacterial damage observed at different laser fluences and nanoparticle sizes was verified by optical transmission, electron microscopy, and conventional viability testing.