Paras Jawaid, Mariame Ali Hassan and Takashi Kondo
Department of Pharmaceutics & Pharmaceutical Technology, University of Sharjah, Sharjah, UAE; Department of Pharmaceutics & Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
Platinum Nanoparticles (Pt-NPs) are known to function as reductive catalysts. They have the ability to scavenge superoxide anion (O2−.) and hydrogen peroxide (H2O2), thus they act as SOD/catalase mimetic. In the context of cancer therapy, cell killing is mostly mediated by intolerable elevation in intracellular reactive oxygen species (ROS) especially following the use of physical modalities such as X-irradiation, hyperthermia and ultrasound (US). Pt-NPs might be meritorious in protecting surrounding tissues from non-selective treatment effects while their presence during treatment might be detrimental in the therapeutic setting. With X-irradiation and hyperthermia, human leukemia U937 cells pretreated with Pt-NPs showed enhanced survival compared to cells treated with either modality alone. On the other hand, with low-intensity pulsed US, cell killing was dramatically enhanced in Pt-NPs -pretreated cells. Here, we show that Pt-NPs may exert differential effects between protection and sensitization depending on their location (extracellular or intracellular) and the nature of the therapeutic modality. The molecular mechanism(s) underlying these effects will be discussed.