Antitumor efficiency of photodynamic therapy of Ehrlich carcinoma mice with the photosensitizer photoran E6

Today, photodynamic therapy (PDT) is one of the most promising methods for the complete eradication of a number of superficial solid malignant neoplasms. In this work, we studied the effectiveness of PDT on Ehrlich carcinoma of mice with the injections of a new photosensitizer (PS) Photoran E6. To determine the optimal drug-light interval, from the time of PS injection to laser irradiation, we studied the distribution kinetics of Photoran E6 in tumors and healthy tissues surrounding them. In assessing the response of the inhibitory effect of Ehrlich carcinoma to PDT, the following indicators were used: inhibition of tumor growth (ITG, %), complete regression (CR, %), absolute growth rates of tumors (K) in mice with continued growth of neoplasia, and an increase in life expectancy (ILE, %) of individuals in the experimental groups compared with the control, according to the criterion of curing animals: the absence of signs of tumor recurrence within 90 days after therapy. The therapeutic potential of PDT for tumor cell devitalization was determined by histological examination of the areas of exposure to laser radiation at 21d after treatment. The results showed that Photoran E6 has a high antitumor activity for PDT of solid Ehrlich carcinoma. Conducting PDT in the optimal time after the injection of PS with certain parameters of laser exposure allows to achieve the maximum inhibitory effect on malignant neoplasms. A pathomorphological study in the areas of photodynamic exposure of the surviving tumor cells was not found.