The role of biocompatible coatings of magnetic nanorods on their thermal response in hyperthermia. Consequences on tumor cell survival

Abstract

There are so many hopes for nanoscience as a tool in the fight against various diseases, notably cancer, that the problem can be approached from many different points of view. In this paper, we focus on two essential aspects. One is the preparation of non-spherical and superparamagnetic magnetic particles, with the right size to be able to exit the blood vessels and be incorporated by cells. The second is their use as agents of hyperthermia. For the first purpose, a two-step method has been followed, in which hematite templates with the desired shape and size are first prepared, and these are subsequently reduced by heat treatment. As a result, nanorods with a length 40 nm and an axis ratio 1:8 are obtained. They are coated with a biocompatible triple layer of polymer. For concentrations up to 300 μg/mL, they are compatible with the MCF7 cancer cell line, and cell uptake is higher than 80 %. Both bare and polymer-coated particles produce heating by magnetic hyperthermia and light irradiation. Finally, cytotoxicity against cancer cells was evaluated, and it was found that photothermia and, above all, magnetic hyperthermia applied to the coated particles are capable of inducing more than 50% cell death.