Iron Oxide Nanoparticles in Cancer Treatment: Cell Responses and the Potency to Improve Radiosensitivity

Abstract

The main concept of radiosensitization is making the tumor tissue more responsive to ionizing radiation, which leads to an increase in the potency of radiation therapy and allows for decreasing radiation dose and the concomitant side effects. Radiosensitization by metal oxide nanoparticles is widely discussed, but the range of mechanisms studied is not sufficiently codified and often does not reflect the ability of nanocarriers to have a specific impact on cells. This review is focused on the magnetic iron oxide nanoparticles while they occupied a special niche among the prospective radiosensitizers due to unique physicochemical characteristics and reactivity. We collected data about the possible molecular mechanisms underlying the radiosensitizing effects of iron oxide nanoparticles (IONPs) and the main approaches to increase their therapeutic efficacy by variable modifications.

Keywords: cancer treatment; ionizing radiation; iron oxide nanoparticles; iron reactivity; radiosensitization.

Figure 1

The main approaches to the modification of iron oxide nanoparticles. IONPs—iron oxide nanoparticles, mAb—monoclonal antibodies, and HA—hyaluronic acid.

Figure 2

General mechanisms of radiosensitization by iron oxide nanoparticles. A black arrow corresponds to ionizing radiation action, and a red arrow corresponds to IONPs action. The arrows correspond to the ways of radiosensitivity enhancement. IR—ionizing radiation, MPs—microparticles, RIBE—radiation-induced bystander effect, and ROS—reactive oxygen spp.