Investigation of Combined Photodynamic and Plasmonic Photothermal Therapy in a Murine Model of Colorectal Carcinoma
Alla B. Bucharskaya1,2*, Vadim D,Genin2, Nikita A. Navolokin1,2, Vladimir A. Bogatyrev3, Natalya A. Shushunova N.A.1,2, Olga I.Guslyakova2, Boris N. Khlebtsov3, Nikolay G. Khlebtsov3, Elina A. Genina2, Valery V. Tuchin2.
1Saratov State Medical University, Saratov, Russia;
2Saratov State University, Saratov, Russia
3 Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov, Russia
Abstract
The aim of the study was to evaluate the effectiveness of combined photodynamic therapy (PDT) and plasmonic photothermal therapy (PPT) in mice with transplanted colorectal cancer.
Materials and methods. Balb/c mice were intramuscularly injected with 20 µl of CT-26 colorectal cancer cell suspension, and when the tumor volume reached 50 mm3, therapy was performed. For PPT therapy, gold nanorods(GNRs), coated with chitosan and citrus pectin were used; they were administered intratumorally in a volume of 20 µl. For PDT, indocyanine green diluted in polyethylene glycol (1:100) was used; it was administered intratumorally to mice in a volume of 20 µl. For combination therapy, and indocyanine green were administered simultaneously to mice at half doses. After 30 minutes, the tumor was irradiated transcutaneously with a diode IR laser with a wavelength of 808 nm and a power density of 2.3 W/cm2 for 5 minutes. The tumor heating temperature was measured using an IRYSYS 4010 (UK) thermal imager. The animals were euthanized, and tumor tissue was collected for histological examination 21 days after therapy.
Results. During the combined therapy, an increase in the tumor heating temperature to 60.5±3 °C was observed; after the therapy, a burn surface appeared on the skin over the tumor tissue. After 21 days, a significant inhibition of tumor growth and pronounced pathomorphosis were noted in the group of mice receiving combined therapy. Conclusions. The proposed technology of combined PDT and PPT therapy induces pronounced pathomorphosis of tumor tissue in mice with transplanted colorectal cancer.
Speaker
Alla Bucharskaya
Saratov State Medical University
Russia
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