Highly reliable, targeted photothermal cancer therapy combined with thermal dosimetry using a near-infrared absorbent

Abstract

Photothermal therapy (PTT) using a photo-absorbent in the near-infrared (NIR) region is an effective methodology for local cancer treatment. Before PTT using a NIR absorbent is executed, the operator generally determines the two parameters of fluence rate and irradiation time. However, even if the irradiation parameters are unchanged, the therapeutic effect of PTT is often different for individual tumors. Hence, we examined the therapeutic effect of PTT using a NIR absorbent (ICG lactosome) while changing two parameters (fluence rate and irradiation time) in various combinations. As a result, there was no robust correlation between those parameters and the therapeutic effect. Compared to those parameters, we found that a more reliable determinant was maintenance of the tumor temperature above 43 °C during NIR irradiation. To reconfirm the significance of the determinant, we developed a new system that can regulate the temperature at the NIR irradiation site at a constant level. By using the new system, we verified the treatment outcomes for tumors in which the NIR absorbent had accumulated. All of the tumors that had been kept at 43 °C during NIR irradiation were cured, while none of the tumors that had been kept at a temperature below 41 °C were cured. In conclusion, PTT using a NIR absorbent with thermal dosimetry is a highly reliable treatment for cancer.

Proof-of-Concept Study of Multifunctional Hybrid Nanoparticle System Combined with NIR Laser Irradiation for the Treatment of Melanoma

“…Of notice, the gold dose used herein was lower than that reported before involving radiation enhancement [62,63]. The radiation dose and time of exposure were selected by taking in consideration irradiation parameters previously reported for photothermal therapy applications [51,52], and exposure limits imposed by law [53,54]. The radiation dose applied was about seven times higher than the exposure limit for a NIR source with the same wavelength.…”

“…Slices were examined under an Olympus BX51 microscope (Olympus Corporation, Tokyo, Japan), im- The NIR laser (JDSU L4-2495-003 coupled to a source Laserpak ARO-485-08-05) used in these experiments had a wavelength of 811 nm and 2.5 W/cm 2 irradiance at the target. The time of exposure was chosen based on our previous in vitro results [50] and considered exposure times and irradiation doses found in the literature [51,52] as well as the exposure limits in guidelines for the use of NIR radiation [53,54].…”

A Novel 89Zr-labeled DDS Device Utilizing Human IgG Variant (scFv): “Lactosome” Nanoparticle-Based Theranostics for PET Imaging and Targeted Therapy

“…Hence, the design of simpler Lactosome through intelligible approaches is essential for future clinical evaluation and application. Up to now, pharmaceutical companies were investigating the possibilities of commercializing photodynamic therapy and photoacoustic diagnosing using the ICG-Lactosome [ 180 , 181 ], while the AB-type Lactosome is currently under consideration by licensing it to an overseas pharmaceutical manufacturer at a non-clinical level.…”

Targeted Cancer Therapy Using Nanoparticles and Antibody Fragments

“…However, tumor targeting is not an easy job! Scientists are targeting tumors in three different mechanisms; (a) Where nanoparticles were pre-exposed with leaky vasculature of tumor cells and encountered with the reticuloendothelial system (RES) or enhanced permeability and retention (EPR) effects [14]. However, (b) active targeting is more advantageous, as inactive targeting, uncontrolled cell proliferative targeting of tumors, and pH and temperature-dependent targeting is possible.…”