title: Photothermal nanotherapeutics and nanodiagnostics for selective killing of bacteria targeted with gold nanoparticles.
abstract: 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/cm(2), 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.
authors.affiliation: Philips Classic Laser Laboratories, and Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. zharovvladimirp@uams.edu
authors.forename: Vladimir P
authors.initials: VP
authors.lastname: Zharov
authors.forename: Kelly E
authors.initials: KE
authors.lastname: Mercer
authors.forename: Elena N
authors.initials: EN
authors.lastname: Galitovskaya
authors.forename: Mark S
authors.initials: MS
authors.lastname: Smeltzer
mesh_terms: D006046:Gold / Q000737:chemistry*; D006358:Hot Temperature; D007834:Lasers; D028022:Low-Level Light Therapy / Q000379:methods*; D008853:Microscopy; D008854:Microscopy, Electron; D046529:Microscopy, Electron, Transmission; D008858:Microscopy, Phase-Contrast; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010789:Phototherapy / Q000379:methods*; D021381:Protein Transport; D013053:Spectrophotometry; D013059:Spectrum Analysis, Raman; D013211:Staphylococcus aureus / Q000378:metabolism / Q000528:radiation effects*; D020349:Surface Plasmon Resonance; D013696:Temperature; D013997:Time Factors
chemical_list: D006046:Gold