Metal/Metal Oxide Nanoparticles for Cancer Therapy

Abstract

Cancer includes a large group of affections that are characterized by an uncontrolled cellular growth and the ability of these cells to spread to distant sites. The uncontrolled cellular growth in cancer cells is attributed to a failure in programmed cell death or apoptosis in which a possible role of oxidative stress has been described. Moreover, oxidative stress is involved in carcinogenesis by influencing intracellular signal transduction and transcription factors directly or indirectly via antioxidants. Metal and metal oxide nanoparticles (NPs) have emerged as innovative tools to address the development of new therapeutic anticancer agents alone or in combination with the classical treatments. The potential use of such NPs against cancer is based on the proapoptotic activity and autophagy, cell growth and metastasis inhibition, and generation of reactive oxygen species as well as radiosensitizing properties described in the studies included in this review. Moreover, we address the different strategies using metal/metal oxide NPs with and without conjugation alone or in combination with radiotherapy or chemotherapy as adjuvants or synergistic agents. NPs obtained from copper, cerium, and zinc were the most studied in various cancer types reported. In many cases, they have been preliminary studies and more research is necessary to increase the knowledge about the therapeutic activity of the metal oxide NPs studied. However, the possibilities that these NPs offer are both extensive and interesting.