Preliminary studies of new photosensitizer for photodynamic treatment of melanoma based on nanostructural forms of Bacteriochlorin p N-alkoxycycloimide alkoxyoxyme methyl ester
G.A. Meerovich, I.G. Meerovich, M.A. Grin, V.I. Pozdeyev, A.G. Tsiprovskij, N.A. Oborotova, V.B. Loschenov, A. Yu. Baryshnikov, A.F. Mironov
A.M. Prokhorov General Physics Institute of RAS, RU
Keywords: photodynamic therapy, bacteriochlorin, nanostructural forms
Abstract:This work is devoted to investigation of Bacteriochlorin p N-alkoxycycloimide alkoxyoxyme methyl ester which possesses its absorption band at 795-800 nm. We have estimated the applicability of PDT with this photosensitizer to treat melanoma. We have developed nanostructural forms of the substance – micellar dispersions on a base of 4% aqueous solution of Cremophor EL and Emuxol-268 and PEG-liposomal dispersion. Main vesicle size for Cremophor and Emuxol based micellar dispersions and PEG-liposomal dispersion was in a range of 12-15 nm, 180 260 nm and 130-180 nm, respectively. Dynamics of photosensitizer accumulation in tumor in comparison to normal tissue was estimated on F1 mice bearing Ehrlich tumor intramuscularly from optical absorption spectra of sensitized biological tissue. Photosensitizer was selectively accumulated in tumor with selectivity index up to 8-12:1 by 4-5 hours after administration. PDT was performed on BDF1 mice bearing B16 melanoma. Photosensitizer was intravenously administered 7 days after inoculation of tumor at doses up to 1 mg/kg. Sensitized tumors were irradiated laser with maximum at 797 nm 2-4 hours after injection of photosensitizer with power density up to 200 mW/cm2 for 20 minutes. Inhibition of tumor growth achieved 91%, increase of animal lifespan exceeded 60%, complete recovery was achieved for 35% of animals.