Iron-dextran as a thermosensitizer in radiofrequency hyperthermia for cancer treatment

Radiofrequency hyperthermia is a recently rediscovered oncotherapy rising in popularity. However, lack of a proper thermosensitizer limits current radiofrequency hyperthermia to be only slightly effective, mostly being used as a subsidiary to a standard oncotherapy. Here, we report that iron-dextran delivers iron ion to cancer cells for cancer-selective accumulation of the iron ion, which functions as a thermosensitizer for radiofrequency hyperthermia. Intravenous injection of iron-dextran to tumor-xenografted mice resulted in selective accumulation of iron ion in the targeted cancer cells. The accumulated iron ion in cancer cells dramatically reacted to radiofrequency wave to result in tumor-selective dielectric temperature increment without harming the surrounding normal tissue. The oncotherapeutic effect of was evaluated using tumor-xenografted mice. The overall anticancer efficacy of radiofrequency hyperthermia after injection of iron-dextran as a thermosensitizer in breast cancer-bearing mice was much better than the efficacy of paclitaxel, a standard chemotherapy drug for cancer. Moreover, hyperthermia using iron-dextran as a thermosensitizer completely eradicated cancer in the tumor xenografted mice. This work suggests that iron-dextran is an ideal thermosensitizer for radiofrequency hyperthermia. We believe that the application of iron-dextran as a thermosensitizer would be a major progress in hyperthermia cancer treatments.