Multifunctional Thymoquinone-Capped Iron Oxide Nanoparticles for Combined Chemo-Photothermal Therapy of Cancer

Due to their unique properties, iron oxide nanoparticles (IONPs) have been widely used for various medical applications. Thymoquinone (TQ) is the main constituent of black seed oil extracted fromNigella sativaseeds. TQ works as an anti-inflammatory, neuroprotective, and anti-cancerous agent. This study reports a novel and simple method for the synthesis of thymoquinone-capped iron oxide nanoparticles (TQ-IONPs). The prepared TQ-IONPs were characterized using different physical techniques. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) showed the uniformly size distribution of the formed TQ-IONPs with an average size of about 10 nm. Zeta potential value for the prepared nano-formulation was found to be - 33.4 +/- 1.5 mV indicated the high stability of TQ-IONPs in colloids. Vibrating sample magnetometer (VSM) revealed the superparamagnetic properties of the formed TQ-IONPs. Sulforhodamine-B (SRB) assay has been used to assess the potent photo-thermal effect of prepared TQ-IONPs against highly aggressive MDA-MB-231 breast cancer cell lines when exposed to NIR laser (2 W/cm(2), 808 nm). Cell viability results showed that TQ-IONPs irradiated with laser (combined photo-chemotherapy) drastically improve the therapeutic efficacy of TQ-IONPs in vitro, compared with the chemotherapeutic effect of TQ, or TQ-IONPs. Fluorescence microscopy showed the higher cellular uptake of TQ-IONPs compared with free TQ, which indicated that the loading of TQ on IONPs greatly enhanced the TQ bioavailability. The results represented in this study may open the door to pursue TQ-IONPs as a novel and viable multifunctional nano-formulation that could be used for various diagnostic and therapeutic applications.