Surface plasmon resonance-induced photoactivation of gold nanoparticles as bactericidal agents against methicillin-resistant Staphylococcus aureus

Abstract

Lucian Mocan,1 Ioana Ilie,2 Cristian Matea,1 Flaviu Tabaran,1 Ersjebet Kalman,1 Cornel Iancu,1 Teodora Mocan3 13rd Surgery Clinic, Department of Nanomedicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania; 2Department of Endocrinology, Department of Nanomedicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania; 3Department of Physiology, Department of Nanomedicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania Abstract: Systemic infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and other bacteria are responsible for millions of deaths worldwide, and much of this mortality is due to the rise of antibiotic-resistant organisms as a result of natural selection. Gold nanoparticles synthesized using the standard wet chemical procedure were photoexcited using an 808 nm 2 W laser diode and further administered to MRSA bacteria. Flow cytometry, transmission electron microscopy, contrast phase microscopy, and fluorescence microscopy combined with immunochemical staining were used to examine the interaction of the photoexcited gold nanoparticles with MRSA bacteria. We show here that phonon–phonon interactions following laser photoexcitation of gold nanoparticles exhibit increased MRSA necrotic rates at low concentrations and short incubation times compared with MRSA treated with gold nanoparticles alone. These unique data may represent a step forward in the study of bactericidal effects of various nanomaterials, with applications in biology and medicine. Keywords: MRSA, SPR, multi-drug resistant bacteria, infection, gold nanoparticles, laser