Substantiation and Prospects of the Application of Chlorine Photosensitizer Photolysis Products for Antimicrobial Therapy in Clinical Practice

Purpose: To find out prospects for the application of photoactivated chlorine derivatives E6 in the clinical practice after analyzing sensitivity of various microorganisms to them. Material and methods: A device for photosensitizer irradiation was manufactured by LLC “New Surgical Technologies” (Moscow, Russia) in compliance with the authors’ technical task. The device includes a power supply unit and 12 ring-shaped LEDs with l~405 nm; nominal power 450 mW, power density of 420-480 mW/cm2. Three tubes with photosensitizer (FS) Radachlorin (manufactured by LLC RADA-PHARMA, Moscow, Russia, registration number LS-001868) in both undiluted and diluted forms in physiological solution in ratio 1:10 and 1:20 were placed in LEDs ring; irradiation lasted for 15 minutes. Then 10 and 50 ml of FS were put on Petri dishes with seeded bacterial colonies immediately after irradiation and 24 hours later. Controls were not irradiated with FS. In total, 20 species of microorganisms isolated from 27 hospitalized patients with various infectious diseases were tested. Results: In experiments, the bactericidal effect of photoactivated Radachlorin at microorganism cultures depending on its concentration and amount was shown. It was also found that photoactivated Radachlorin is active against most Gram-positive microorganisms and is not active against Gram-negative cultures in tested concentrations and amounts. Besides, the defined sensitivity differed significantly for some strains of microorganisms of the same species which needs further research. FS dark effect was also revealed. It was also found that Radachlorin photolysis products can retain their activity for, at least, 24 hours. Conclusion: The obtained results confirm possible antimicrobial and antimycotic effects of photoactivated FS when being applied to infected patients what gives grounds to continue research in this direction in order to determine optimal parameters of photoactivation and selection of the most effective photosensitizers depending on their sensitivity to various microorganisms.