Transferrin as a thermosensitizer in radiofrequency hyperthermia for cancer treatment

Abstract

One of the main characteristics of cancer tissues is poor development of neovascularization that results in a limited blood circulation. Because of this phenomenon, it is harder for cancer tissues to diffuse their elevated heat into other parts of the body. The scientific principle of radiofrequency hyperthermia relies on this quality of cancer tissues which with higher temperature becomes more apparent. Despite the obvious necessity to selectively heat the cancer tissue for radiofrequency hyperthermia, a proper thermosensitizer has not been developed until now. Here, we show that transferrin containing ferric ion could be an ideal thermosensitizer for the increased efficiency of radiofrequency hyperthermia. In our result, the ferric ion-enriched cancer tissues dramatically react with 13.56 MHz radiofrequency wave to cause cancer-selective dielectric temperature increment. The overall anticancer efficacy of a 13.56 MHz radiofrequency hyperthermia using transferrin as a thermosensitizer was much higher than the oncotherapeutic efficacy of paclitaxel, successfully eradicating cancer in a tumor-xenografted mouse experiment.

<p>Molecular Antenna-Sensitized Upconversion Nanoparticle for Temperature Monitored Precision Photothermal Therapy</p>

“…The Rare-earth acetates (CH 3 COO) 3 ) and Hoechst were purchased from Sigma-Aldrich Co., Ltd. All chemicals were of analytical grade. CCK-8 was obtained from Dojindo China Co. Ltd. RPMI 1640 cell culture medium, fetal bovine serum, penicillin, and streptomycin were obtained from Gibco Invitrogen.…”

“…All aqueous solutions were prepared using ultrapure water, which was obtained through an Advanced-iv-08 water purification system (Chengdu, China). 3 •4H 2 O (with and without) were added and stirred for another 30 min. Subsequently, 10 mL of ethanol containing 10 mmol of NaF was added to the above solution and stirred for another 30 mins.…”

“…EMT-6 cells (1×10 7 cells/mL, 100 μL) were inoculated subcutaneously into the back of a nude mouse. Once the volume approached 100 mm 3 , the mouse was anaesthetized with pentobarbital sodium (i.p., 60 mg/kg) and intravenously injected with 100 μL of the NPs (10 mg/mL). Twelve hours later, the mouse was treated with an 808 nm laser in situ (0.8 W/cm 2 ) for 10 mins.…”

“…Many thermal sources are used for this method, such as microwave, radiofrequency and nearinfrared light. [1][2][3] As a local therapeutic modality, photothermal therapy (PTT) utilizes photoabsorbers to generate heat from near-infrared light absorption, leading to the thermal ablation of cancer cells. 4 During PTT, chromophores contained in healthy tissue within the light path can also absorb energy, reducing the effectiveness of heat deposition within tumor cells and increasing nonspecific injury to adjacent healthy tissue.…”

Aspects of Photodynamic Inactivation of Bacteria

“…Another approach involved using gold nanoparticles, which were heated by an electric field using 13.56 MHz radiofrequency, and effectively destroyed human pancreatic cancer cells in vitro [49]. The same frequency was used in other studies to activate fullerene [50] and transferrin [51] and to eradicate cancer tumors in vitro and in vivo. A possible mechanism of radiosensitization, according to Tamarov et al [48] and Chung et al [51], may be thermal activation of sensitizers by hyperthermia, caused by dissipation of electromagnetic energy, which leads to thermal damage of cancer cells.…”