Photoinduced Dynamics and Toxicity of a Cancer Drug in Proximity of Inorganic Nanoparticles under Visible Light

Abstract

Drug sensitization with various inorganic nanoparticles (NPs) has proved to be a promising and an emergent concept in the field of nanomedicine. Rose bengal (RB), a notable photosensitizer, triggers the formation of reactive oxygen species under green-light irradiation, and consequently, it induces cytotoxicity and cell death. In the present study, the effect of photoinduced dynamics of RB upon complexation with semiconductor zinc oxide NPs is explored. To accomplish this, we successfully synthesized nanohybrids of RB with ZnO NPs with a particle size of 24 nm and optically characterized them. The uniform size and integrity of the particles were confirmed by high-resolution transmission electron microscopy. UV/Vis absorption and steady-state fluorescence studies reveal the formation of the nanohybrids. ultrafast picosecond-resolved fluorescence studies of RB-ZnO nanohybrids demonstrate an efficient electron transfer from the photoexcited drug to the semiconductor NPs. Picosecond-resolved Förster resonance energy transfer from ZnO NPs to RB unravel the proximity of the drug to the semiconductor at the molecular level. The photoinduced ROS formation was monitored using a dichlorofluorescin oxidation assay, which is a conventional oxidative stress indicator. It is observed that the ROS generation under green light illumination is greater at low concentrations of RB-ZnO nanohybrids compared with free RB. Substantial photodynamic activity of the nanohybrids in bacterial and fungal cell lines validated the in vitro toxicity results. Furthermore, the cytotoxic effect of the nanohybrids in HeLa cells, which was monitored by MTT assay, is also noteworthy.

Biomedical Applications of Photo- and Sono-Activated Rose Bengal: A Review

“…Several photosensitizers have been used for PDT for treating cancer due to their ability to induce ROS formation, which can cause cell death. 45 The efficacy of the substance depends on its physical and chemical characteristics, such as chemical purity, charge, solubility, distinct localization in cancer cells, residence, and accumulation time from drug administration. 45 RB is an anionic substance with low solubility in lipids which negatively affects its capability to cross biological membranes.…”

“…51 Gianotti et al 52 and Uppal et al 53 developed organically modified silica nanoparticles with RB and showed phototoxicity on skin, 52 oral, and breast 53 cancer cells in vitro. Nanoparticles loaded with RB and made of different materials, such as ZnO 45 and PVP+Janus, 54 were studied, demonstrating greater ROS generation and toxicity in vitro and selectiveness for cancer cells, respectively.…”

Novel one pot synthesis and spectroscopic characterization of a folate-Mn3O4 nanohybrid for potential photodynamic therapeutic application

“…Aer detailed photophysical characterization, ROS generation ability of the nanohybrid (FA-Mn 3 O 4 NP) was evaluated in vitro by monitoring the conversion of DCFH, a widely used marker for detection of ROS, to dichlorouorescein (DCF) in aqueous medium. 30 In presence of ROS, non-uorescent DCFH undergoes oxidation to produce orescent DCF (l ex ¼ 488 nm; l em ¼ 520 nm). So, we monitored the uorescence intensity of DCF at 520 nm (l ex ¼ 488 nm) with respect to time (Fig.…”

Citrate Functionalized Mn3O4in Nanotherapy of Hepatic Fibrosis by Oral Administration

“…In vitro ROS generation ability of the NPs and acid treated NPs were evaluated using DCFH-DA following a reported method without any modification [22]. Jobin Yvon Model Fluoromax-3 was used to measure the emission intensity.…”