Study of the effect of photodynamic therapy on the optical properties of mouse tumor models
Inessa V. Markova1,2, Daria V. Pominova1,2, Alexey S. Skobeltsin1,2, Igor D. Romanishkin1, Anastasia V. Ryabova1,2; 1Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia; 2Institute of Engineering Physics for Biomedicine, National Research Nuclear University MEPhI, Moscow, Russia
Abstract
Photodynamic therapy (PDT) is a promising and minimally invasive method of cancer treatment. The PDT effectiveness strongly depends on the depth of penetration of excitatory radiation, which is determined by the optical properties of the tumor. In addition, these properties may be altered during PDT due to the destruction of tumor cells, the tumor microenvironment, edema formation and damage to the extracellular matrix. On the one hand, these injuries are the target of PDT as they may further enhance the penetration of chemotherapy agents into the tumor. However, alterations in optical characteristics can affect the efficacy of the PDT session.
This work examines changes in the optical properties (scattering and absorption coefficients, autofluorescence) of tumor tissues in transplanted mouse models after PDT with chlorin e6 photosensitizer (10 mg/kg). The irradiation was carried out using a laser source at 660 nm (power density 100 mW/cm2, light dose 50 J/cm2). Diffusely scattered light spectra were recorded using fiber spectrometer Lesa-01-Biospec (BIOSPEC, Russia) in the visible range and DWARF-star (StellarNet, USA) in the short-wavelength infrared range. Fluorescence was measured using a Lesa-01-Biospec fiber spectrometer and a video fluorescence camera (BIOSPEC, Russia). The lifetimes of tumor autofluorescence and photosensitizer fluorescence were also studied with a system of Hamamatsu streak camera and streak scope (C9300 and C10627-13).
Therefore, the changes in the scattering, absorption and fluorescence properties of the tumor during PDT were analyzed. The results can be used to optimize the PDT procedure parameters.
The study was supported by the RSF (grant No. 25-12-00436).
Speaker
Inessa Markova
Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia; 2Institute of Engineering Physics for Biomedicine, National Research Nuclear University MEPhI, Moscow, Russia
Russia
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