Diffuse Optical Spectroscopy Monitoring of Experimental Tumor Oxygenation after Red and Blue Light Photodynamic Therapy

Autor: Anna Orlova, Yulia Perevalova, Ksenia Pavlova, Natalia Orlinskaya, Aleksandr Khilov, Daria Kurakina, Maria Shakhova, Mikhail Kleshnin, Ekaterina Sergeeva, Ilya Turchin, Mikhail Kirillin
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Photonics, Vol 9, Iss 1, p 19 (2021)
Druh dokumentu: article
ISSN: 2304-6732
DOI: 10.3390/photonics9010019
Popis: Photodynamic therapy (PDT) is an effective technique for cancer treatment based on photoactivation of photosensitizer accumulated in pathological tissues resulting in singlet oxygen production. Employment of red (660 nm) or blue (405 nm) light differing in typical penetration depth within the tissue for PDT performance provides wide opportunities for improving PDT protocols. Oxygenation dynamics in the treated area can be monitored using diffuse optical spectroscopy (DOS) which allows evaluating tumor response to treatment. In this study, we report on monitoring oxygenation dynamics in experimental tumors after PDT treatment with chlorin-based photosensitizers using red or blue light. The untreated and red light PDT groups demonstrate a gradual decrease in tumor oxygen saturation during the 7-day observation period, however, the reason is different: in the untreated group, the effect is explained by the excessive tumor growth, while in the PDT group, the effect is caused by the blood flow arrest preventing delivery of oxygenated blood to the tumor. The blue light PDT procedure, on the contrary, demonstrates the preservation of the blood oxygen saturation in the tumor during the entire observation period due to superficial action of the blue-light PDT and weaker tumor growth inhibition. Irradiation-only regimes show a primarily insignificant decrease in tumor oxygen saturation owing to partial inhibition of tumor growth. The DOS observations are interpreted based on histology analysis.
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