Anti-Tumor Efficacy of Photodynamic Therapy of Solid Tumors in Laboratory Animals with Guanidine and Biguanidine Derivatives of Chlorine e6.

We evaluated antitumor efficacy of photodynamic therapy of murine Ehrlich carcinoma and rat sarcoma M-1 with new photosensitizers 13-N-(4-aminobutyl)amydo chlorine e6 (1), 13-(5-guanidylbutanamido)-chlorine e6 (2), and 13-(5-biguanidylbutanamido)-chlorine e6 (3). The inhibiting effect of the photodynamic therapy was evaluated by the following parameters: tumor growth inhibition, complete regression of the tumors, and absolute growth rate of the tumor nodes in animals with the continued neoplasia growth. The criterion of cure was the absence of tumors up to 90 days after the therapy.

On the Pathomorphological Pattern of the Efficiency of Photodynamic Therapy of Murine Melanoma B16 Using a New Photosensitizer Based on Chlorin e Conjugate with a Prostate-Specific Membrane Antigen.

Photodynamic therapy (PDT) is an effective treatment for a number of solid malignancies. In this work, the antitumor efficacy of photodynamic therapy for murine B16 melanoma with intravenous administration of a new photosensitizer (PS) based on the chlorin e conjugate with a prostate-specific membrane antigen (PSMA) was studied in vivo. We have previously published the data obtained in the first part of the study: the dynamics of PS accumulation in the tumor and surrounding tissues and the antitumor efficacy of the photodynamic therapy, which was evaluated by the regression parameters and morphological characteristics of the tumors-including by the complete regression of the tumors, the absolute growth rate of the tumors among the mice with continued tumor growth, and an increase in life expectancy compared to the control.

Photodynamic Therapy of Melanoma B16 with Chlorin E6 Conjugated with a PSMA-Ligand.

The efficacy of a new photosensitizer of chlorin E6 conjugated with a prostate-specific membrane antigen (PSMA) in photodynamic therapy of murine melanoma B16 was studied in in vivo experiments. The dynamics of photosensitizer accumulation in the tumor and surrounding tissues was evaluated and antitumor efficacy of photodynamic therapy was assessed by parameters of regression and morphological characteristics of experimental transplanted melanoma B16. The inhibitory effect of photodynamic therapy on melanoma was evaluated by complete regression of the tumor, absolute tumor growth coefficient in animals with continuation of tumor growth, and the increase in life span in comparison with the control; the criterion of cure was the absence of signs of tumor recurrence in mice within 90 days after therapy.

Photodynamic Therapy of Sarcoma M-1 in Rats with Photosensitizer Photoran E6.

We studied the effectiveness of photodynamic therapy with the photosensitizer Photoran E6 on the model of rat sarcoma M-1 positive for mutant p53 gene. Experiments showed that Photoran E6 exhibits high antitumor activity in photodynamic therapy of solid tumor of the connective tissue. Photodynamic therapy carried out during the optimal period after injections of Photoran E6 with the determined parameters of laser exposure allows achieving the maximum inhibitory effect on sarcoma M-1: 100% cured animals.

A method for improving the efficiency of therapy for melanoma.

A method for photodynamic therapy was developed in experiments on the model of melanoma B16. The photosensitizer is injected by two doses, while laser exposure is carried out during coincidence of its maximum accumulation phases in tumor vessels and cells. This method increased the percentage of animals with complete regression of the tumor, decreased the coefficient of absolute tumor increase in animals with progressive tumor growth, increased survival of mice, and significantly decreased melanoma metastasizing to the lungs in comparison with untreated animals and even with the standard photodynamic therapy.