Treatment of rat model tumor with combined photodynamic/photothermal therapy
The aim of the study was to develop a combined technology of photodynamic therapy (PDT) and plasmonic photothermal therapy (PTT) in rats with transplanted cholangiocarcinoma of the PC-1 line. Indocyanine green was used as a photosensitizer in PDT, which was dissolved in polyethylene glycol (PEG) and administered intratumorally to rats. For PTT, gold nanorods (GNR) functionalized with PEG were injected intratumorally at a concentration of 400 μg/ml. An hour after the injections, the tumor was irradiated percutaneously with an 808 nm diode infrared laser at a power density of 2.3 W/cm2 for 15 min. The withdrawal of animals and sampling of tumor tissues for histological examination was performed 72 hours and 21 days after combination therapy.
During the combined therapy, there was a pronounced rise in the temperature of local heating of the tumor up to 60±4.1ºС. After 72 hours, pronounced necrotic changes were observed in the tumor tissue, necrosis fields occupied up to 80% of the area. Preserved tumor cells were found only on the periphery of the tumor; they showed a decrease in the expression of the proliferation marker and an increase in the expression of the apoptosis marker. After 3 weeks, a significant inhibition of tumor growth was noted.
The proposed combination therapy technology causes pronounced damage to tumor tissue in rats with transplanted cholangiocarcinoma.
The work was supported by RSF grant 23-14-00287.
Vadim D. Genin
Saratov State University, Saratov, Russia; Tomsk State University, Tomsk, Russia
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