New Near-Infrared Photosensitizers Based On Bacteriochlorin P Derivatives: Preliminary Results Of In Vivo Investigations

This work is devoted to investigation of several new photosensitizers on a base of bacteriochlorin p macrocycle. Investigations of photosensitizers in vivo and experimental PDT were performed on F, mice bearing Erlich tumor and BDF1 mice bearing B16 melanoma. Spectra of fluorescence and absorption of tissue were studied in vivo using fiber-optic spectroanalyzer LESA. All investigated photosensitizers possess intensive absorption in a range of 730-800 nm, where the intrinsic absorption of the biological tissue has its minimum. Dynamics and selectivity of sensitizer accumulation in tumor and normal tissue were estimated from spectra of absorption or fluorescence of sensitized tissue in vivo. The investigation has shown that the optimum time range to start PDT irradiation of tumor is 10-30 min after administration. All photosensitizers clear from the normal tissue in less than 24 hours. Photodynamic efficiency was estimated by comparison of the tumor volume growth in control and treated animal groups. All studied photosensitizers have shown high photodynamic efficiency of relatively large tumors, index of tumor growth inhibition exceeded 70%. Bacteriochlorin p N-methoxycycloimide oxyme methyl ester was also shown to be efficient for PDT of B 16 melanoma, causing tumor growth inhibition more than 90%.