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

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 nano-particles 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.

Antibacterial and Antibiofilm Activities of the Photothermal Therapy Using Gold Nanorods against Seven Different Bacterial Strains

“…Mocan et al reported a MIC for spherical gold nanoparticles against methicillinresistant S. aureus with and without photoactivation of 6.25 and 25 g⋅mL −1 , respectively. These values are higher than those reported in this investigation, probably due to the higher photothermal activity of AuNRs [20]. In endodontics, NaClO is used as the routine disinfectant due to its high effectiveness; Heling obtained a MIC of 1570 g⋅mL −1 for NaClO against S. sobrinus, E. faecalis, and S.…”

Novel Clinical Trial for Treatment of Infected Subcutaneous Fistula in Female Griffon Dog using Gold Nano-Rod Assisted Near-Infrared Plasmonic Photothermal Therapy

“…Superficial tissues had numerous small vessels, while larger blood vessels were visible in the deep tissues In the present study, there were two challenges; the first was to achieve bactericidal effect of PPTT against ESβL Klebsiella pneumoniae and the second was enhancement of fistula healing without evidence of hyperthermia side effects on the tissues. Regarding first one, plasmonic photothermal therapy has been extensively investigated (in vitro) as an alternative technique in the biomedical area like determination of its bactericidal and antibiofilm activities against different strains of oral microorganisms (Castillo-Martínez, et al, 2015) [30], using of covalently primary antibodies linked gold nanorods to selectively destroy the pathogenic Gram-negative bacterium, Pseudomonas aeruginosa after exposure to near-infrared radiation (norman, et al, 2008) [31], using surface plasmonic resonance-induced photo-activation of gold nanoparticles as bactericidal agents against methicillin-resistant Staphylococcus aureus (Mocan, et al, 2014) [32], developing a drug delivery platform where gold nanorods (AunRs) are conjugated to rifampicin (RF), which is released after the uptake into macrophage cells (RAW264.7) [22] and studying the action of bactericidal gold nanoparticles on Escherichia coli (Cui, et al, 2012) [33]. In addition to that, a new antibacterial gold nanorod (GnR) conjugated magnetic nanoparticle (MnP) composite (GnR-MnP) was synthesized successfully for the eradication of antibiotic resistant nosocomial pathogens in water to improve the water quality (Ramasamy, et al, 2014) [34].…”

“…That was described previously as the most effective size in the plasmonic photothermal heat generation against bacterial and cancer cells (MacKey, et al, 2014 and Castillo-Martínez, et al, 2015) [38,30]. The previous in vitro bactericidal studies irradiated 1 mL of GnP solution at various concentrations placed in a glass cuvette with approximately one cm bottom surface for 10 minutes, using an 808 or 810 nm wavelength laser with variable output power (up to 2 W/cm2 diode) which was fixed above the surface, approximately 2 cm2, in a vertical position and this dispersion reached a temperature up to 70°C (Mocan, et al, 2014 and Castillo-Martínez, et al, 2015) [32,30]. These conditions are not logically acceptable among the clinical level as this temperature will lead to tissue burn.…”

Laser thermal ablation of multidrug-resistant bacteria using functionalized gold nanoparticles

“…[15][16][17][18][19][20][21][22] Various types of GNP complexes (protein-coated GNPs, peptide-coated GNPs, GNPs coated with nucleic acids, drugs) are available for delivery to cells and organs.…”

“…2,6,18,[23][24][25][26] This property is significant because it can be exploited to develop nano-photothermal vectors in order to destroy bacteria at a molecular level. The present paper summarizes the latest advancements in the field of nanotargeted laser hyperthermia of MDR bacteria mediated by GNPs (Table 1).…”