Effect of Size-Dependent Photodestructive Efficacy by Gold Nanomaterials with Multiphoton Laser

Abstract

The photostability, photodestructive efficacy, two-photon excitation cross section, and two-photon fluorescence of gold nanoparticles conjugated with a hydrophilic photosensitizer, indocyanine green, via multiphoton laser exhibited an increased size effect in methicillin-resistant Staphylococcus aureus and A549 cancer cells that was dependent on the size of multifunctional gold nanomaterials, but the effect only occurred when nanomaterials within 100 nm in diameter were used. Besides, the enhanced effectiveness of photodestruction, photostability, and contrast probe indicated an additive effect in the therapeutic and imaging efficiency of multifunctional gold nanomaterials. Consequently, the preparation of the multifunctional gold nanomaterials and their use in biomedical applications via multiphoton laser is an alternative and potential therapeutic approach for killing bacteria and for ablating cancer cells.

<p>Two-Photon Photoexcited Photodynamic Therapy with Water-Soluble Fullerenol Serving as the Highly Effective Two-Photon Photosensitizer Against Multidrug-Resistant Bacteria</p>

“…A large cross-section is desirable for monitoring molecular activities in vitro or in vivo through two-photon techniques. 18,19,36 The calculated absolute cross-section of TPE for water-soluble C 60 (OH) 30 was approximately 1187.50 GM (Rhodamine B was selected as the standard reference 9 for determining the cross-section; Figure 3C and Table 3), which was similar to that in other studies. 27,47 After further investigation, lifetime was also measured; sequentially, the effects of radiative and nonradiative decay rates on QY and lifetime were calculated.…”

“…intensity was detected based on the absorbance of XTT at 470 nm, and GSH after interaction with materials, 18,19,[36][37][38][39][40][41][42] and the quantities of 1 O 2 and O 2 .…”

“…Considering that false-positive signals of ROS might have resulted from interactions between materials and ROS reagents (SOSG, t-MVP, XTT, and GSH) 18,19,[36][37][38][39][40][41][42] and might have led to compromised results, another detection method was used to measure and monitor ROS formed by the laser-irradiated material-treated bacteria (Table 1); ROS presented a trend similar to that in Table S2 (Supplementary Information), consistent with the signal of 1 O 2 phosphorescence at 1270 nm emitted from materials ( Figure 3B).…”

Graphene oxide conjugated with polymers: a study of culture condition to determine whether a bacterial growth stimulant or an antimicrobial agent?

“…Superoxide radical anion (O 2 · − ), singlet oxygen ( 1 O 2 ), and hydrogen peroxide (H 2 O 2 ) are three types of ROS that induce DNA damage, the oxidation of fatty acid amino acid, and enzyme inactivation, all of which lead to cell injury. Firstly, the intensity of superoxide radical anion and singlet oxygen were measured by monitoring the absorbance of 2, 3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) [ 7 , 28 ] at 470 nm and the fluorescence intensity from a Singlet Oxygen Sensor Green Reagent [ 16 ] after the bacteria were incubated with GO and GO-based materials in a range of dosages (10–300 μg mL −1 ). When GO-treated-bacteria are incubated with both culture media for 3 h, they do not induce apparent oxidative stress at low concentrations.…”

“…Graphene oxide materials (up to 20 μm wide) were delivered at the doses of 10–300 μg mL −1 . GO-, GO-POAA- and GO-chitosan-treated-bacteria (OD 600 ~ 0.05) were respectively incubated with either nutrient medium or PBS alone for 3 h at 37 °C and then mixed and incubated with 1 mL 0.45 mM XTT for 5 h in the dark [ 7 , 28 ]. XTT interacts with superoxide radical anion and form the XTT-formazan, which is strongly absorbed at a wavelength of 470 nm.…”