Fluorescence lifetime-based intracellular thermometry for photothermal therapy

Abstract Photo-thermal therapy (PTT) is a rapidly developing approach for cancer treatment, that has greatly benefited from the tremendous advances in the synthesis of plasmonic nanoparticles (NPs), which can be used as light sensitive agents. This approach is based on the local induction of hyperthermia via light irradiation of plasmonic NPs in order to thermally kill cancerous cells. Such an approach ensures a high precision of treatment and the mechanism of action makes it as a valid alternative for treatment of malignant neoplasms with a multi-drug resistance. However, in order to minimize the adverse effects of PTT it is necessary to precisely measure and control the achieved temperatures at the tumor foci during light irradiation. Herein we report a novel technique to monitor intracellular temperatures during PTT based on temperature sensitive fluorescent dye, Rhodamine B. These findings may improve the quality of treatment and reduce unwanted adverse effects.