Intracellular ROS Induction by Ag@ZnO Core–Shell Nanoparticles: Frontiers of Permanent Optically Active Holes in Breast Cancer Theranostic

Abstract

In this study, we investigated whether ZnO coating on Ag nanoparticles (NPs) tunes electron flux and hole figuration at the metal-semiconductor interface under UV radiation. This effect triggers the photoactivity and generation of reactive oxygen species from Ag@ZnO NPs, which results in enhanced cytotoxic effects and apoptotic cell death in human breast cancer cells (MDA-MB231). In this context, upregulation of apoptotic cascade proteins (i.e., Bax/Bcl2 association, p53, cytochrome c, and caspase-3) along with activation of oxidative stress proteins suggested the occurrence of apoptosis by Ag@ZnO NPs in cancer cells through the mitochondrial pathway. Also, preincubation of breast cancer cells with Ag@ZnO NPs in dark conditions muted NP-related toxic effects and consequent apoptotic fate, highlighting biocompatible properties of unexcited Ag@ZnO NPs. Furthermore, the diagnostic efficacy of Ag@ZnO NPs as computed tomography (CT)/optical nanoprobes was investigated. Results confirmed the efficacy of the photoactivated system in obtaining desirable outcomes from CT/optical imaging, which represents novel theranostic NPs for simultaneous imaging and treatment of cancer.

Zn(II) Di‐isobutyldithiocarbamate Complex Enabled Efficient Synthesis of Au/ZnS Nanocomposite Core‐shell in One Pot

“…The nanocomposites consisting of noble metallic and transition metal chalcogenide (TMC) nanomaterials are promising for scientific research due to plasmon‐exciton interaction . Such multifunctional nanomaterials have attracted great interest in last few years due to their distinctive physical as well as chemical properties which lead to admirable performance in electronic, magnetic, photocatalytic, optoelectronic and biological applications over their constituent materials. A wide diversity of metal‐ TMC based hybrid nanostructures such as core‐shell, tetrapod, pentapod, nanoflower, dumbbells etc are reported.…”

Supramolecular Insights into Domino Effects of Ag@ZnO-Induced Oxidative Stress in Melanoma Cancer Cells

“…Synthesis of Ag@ZnO Core-Shell Nanoparticles. Ag@ZnO NPs were synthesized using a wet chemical route as previously described 25 . Briefly, Ag NPs were suspended in 0.06 M zinc acetate/DI solution and stirred for 30 min, then were added to NaOH/ methanol (0.4 M) and stirred at 90 C for 10 min.…”

“…Fluorescent Labelling of the Nanoparticles and uptake study by Confocal Microscopy. In order to assess the cellular uptake of Ag@ZnO NPs, Rhodamine-B isothiocyanate (Rh-B) fluorescent dye (Merck, Germany) was conjugated to NPs following a previously published protocol 25 . Then Rh-B-labelled-NPs (50 µg/ml) were dispersed in water and added to cells (n=1×10 6 ).…”

“…The size of NPs represents one of the determining factors for cellular uptake 30 .Previous reports state that 50-80 nm NPs are mostly taken up by endocytosis route 31 . The Ag@ZnO NPs present a size of around 70 nm in cell culture media and can therefore be readily taken up by endocytosis pathways 25 . While uptake is observed in both healthy and cancerous cells, increased internalization is observed in cancer cells due to their higher metabolism 29 .…”

“…Recently, Therapeutics based on ROS generating NPs, capitalize on inducible ROS generation, has gained increasing attention 24 . Previously, we have shown that core/shell NPs of Ag and ZnO (Ag@ZnO NPs) led to increased ROS generation, upon exposure to UV irradiation, representing a promising candidate for ROS-mediated cancer cell death 25 .…”