Superparamagnetic nanodevices as singlet oxygen carriers for cancer therapy

Abstract

Cancer is a pathology composed of a complex tissue society and its incidence has increased over the last years. In this sense, it is necessary to develop and/or improve treatments in order to reduce the amount of patients that come to death. Among the available cancer treatments, radiation therapy is one of the most used. Combined with radiotherapy, magnetic hyperthermia, which heats up the cancer cells with alternated magnetic fields and superparamagnetic nanoparticles, is able to improve the effectiveness of radiotherapy. Photodynamic therapy can also be used in combination with radiotherapy. In this case, a photosensitizer, when exposed to UV visible light, produces reactive oxygen species, such as singlet oxygen, that causes cell damage. However, due to the low penetration of visible light in biological tissues, the photodynamic therapy is limited to superficial tumors. Therefore, the use of superparamagnetic nanodevices as singlet oxygen carriers could overcome this problem, delivering this reactive specie inside deep tumor cells. The objective of this project is to develop nanodevices consisting of a superparamagnetic core and a shell of an aromatic compound for a combination of several cancer therapies. The aromatic shell will trap the singlet oxygen, releasing it in a controlled way during the process of magnetic hyperthermia. When released, the singlet oxygen can directly react with DNA bases damaging them, besides allowing that tumoral cells become more oxygenated, decreasing their radio-resistance, increasing the biological damage to tumoral tissue and, consequently, the efficacy of the radiotherapy treatment. Thus it is evident that these multifunctional nanodevices would allow the combination of radiotherapy with photodynamic therapy and magnetic hyperthermia.