Cancer stem cells (CSCs): the blockage of metastatic and stemness properties by metal nanoparticles

Cancer stem cells (CSCs) are comprised of hierarchically-organized subpopulations of cells with distinguished phenotypes and tumorigenic capabilities that concrete to metastasis and cancer recurrence. According to related studies, their presence stands as the main reason of cancer associated fatalities. The fundamental feature of these cells is their ability to provide resistance towards conventional treatments or facilitate escaping routes, which include the overexpression of multifunctional ATP-binding cassette (ABC) efflux transporter gene family, metabolism reprogramming, and activation of survivance pathways . Conventional therapies are mainly capable of annihilating cancer cells, while lacking the ability to remove vital CSCs. The recurrence of tumors can be impeded through the targeting of CSCs by different therapies. Nanoparticles with unique properties have emerged as a promising approach for combating stem cancer cells. Therefore, the exertion of nanoparticles, especially metal nanoparticles - based drug delivery systems in cancer imaging and remedial treatment, can surpass the obstacles of conventional treatments. Therefore, the possibility of achieving nonspecific toxicities through the administration of lower but more accurate targeted doses can be provided by the production of theranostic metal nanoparticles and the incorporation of payload drugs into metal nanoparticles carriers, which requires a particular focus on the significance of biomarker targeting for remedial purposes and the unique contrast-enhancing features of theranostic metal nanoparticles for facilitating image-guided delivery. Despite the benefits of using nanoparticles for treating cancer stem cells, yet it is necessary to surpass the numerous challenges and further conduct comprehensive researches.