Near Infrared-Activated Dye-Linked ZnO Nanoparticles Release Reactive Oxygen Species for Potential Use in Photodynamic Therapy

Abstract

Novel dye-linked zinc oxide nanoparticles (NPs) hold potential as photosensitizers for biomedical applications due to their excellent thermal- and photo-stability. The particles produced reactive oxygen species (ROS) upon irradiation with 850 nm near infrared (NIR) light in a concentration- and time-dependent manner. Upon irradiation, ROS detected in vitro in human umbilical vein endothelial cells (HUVEC) and human carcinoma MCF7 cells positively correlated with particle concentration and interestingly, ROS detected in MCF7 was higher than in HUVEC. Preferential cytotoxicity was also exhibited by the NPs as cell killing was higher in MCF7 than in HUVEC. In the absence of irradiation, dye-linked ZnO particles minimally affected the viability of cell (HUVEC) at low concentrations (<30 μg/mL), but viability significantly decreased at higher particle concentrations, suggesting a need for particle surface modification with poly (ethylene glycol) (PEG) for improved biocompatibility. The presence of PEG on particles after dialysis was indicated by an increase in size, an increase in zeta potential towards neutral, and spectroscopy results. Cell viability was improved in the absence of irradiation when cells were exposed to PEG-coated, dye-linked ZnO particles compared to non-surface modified particles. The present study shows that there is potential for biological application of dye-linked ZnO particles in photodynamic therapy.

Interactions of Zinc Oxide Nanostructures with Mammalian Cells: Cytotoxicity and Photocatalytic Toxicity

“…Successful PDT treatment depends on the type of tumors and proper selection of light source. So, near infrared (NIR) light (700–1300 nm) with a deeper penetration depth into human body has attracted considerable attention for therapeutic purposes [ 172 ]. However, prolonged exposure to NIR is also harmful to the adjacent normal tissues due to the heating-induced tissue damage.…”

Influence of Green Synthesized Zinc Oxide Nanoparticles on Molecular Interaction and Comparative Binding of Azure Dye with Chymotrypsin: Novel Nano-Conjugate for Cancer Phototherapy

“…From the maximal inhibitory concentration (IC50), the cytotoxicity was found to be 8.2 µM and 6.0 µM for AzC alone and AzC-ZnONPs respectively. The AzC-ZnONPs nanoconjugate show more toxicity compared to the AzC alone at the higher concentration due to the combined ROS generation which results in the killing of more cancer cells as compared to AzC alone [ 41 ]. These findings imply that AzC-ZnONPs nanoconjugates should be explored more for the exciting prospect of their use as an anticancer agent.…”

Multifunctional ZnO nanostructures: a next generation nanomedicine for cancer therapy, targeted drug delivery, bioimaging, and tissue regeneration

“…They have shown that NIH: OVCAR-ZnO-MTAP conjugates do not show any toxicity in dark but are useful in PDT for deep cancer treatment [164]. Recently, ZnO NPs were conjugated with the NIR-active dyes and upconversion nanomaterials to expand the use of ZnO as photosensitizer with NIR/ X-rays light source for further improvement of PDT for deep-seated tumors [161,[165][166][167][168][169][170]. In 2020, Nagi et al reported NIR-activated dye-linked ZnO NPs for PDT showing excellent thermal-and photo-stability.…”