Effect of amphiphilic polymers on the photodynamic activity of rose bengal in vitro and in vivo conditions

Abstract

It has been shown that amphiphilic polymers (AP) (Pluronic F108 and polyvinylpyrrolidone) increase the activity of rose bengal (RB) in the photogeneration of 1O2 in vitro and in vivo conditions. In particular, in the presence of AP, the intensity of luminescence of 1O2 generated by exited RB increased. Perhaps RB forms loosely bound complexes with AP, which promotes disaggregation of the dye. According to x-ray diffraction data, the degree of crystallinity of pluronic decreases during crystallization from joint solutions with RB and a large period in the packing of its crystallites is disrupted. This may indicate the localization of the dye in the intercrystalline amorphous regions of pluronic due to complexation RB + F108. In vitro experiments showed that the phototoxicity of the dye against A549 lung carcinoma cells increases in the presence of F108 and PVP. Under photodynamic exposure to model wounds in rats using the RB + F108 complex as a PS, there was an increase in reparative processes in the wounds, while pluronic F108 weakened the negative impact of RB on microvessels and prevented the development of a local hemorrhagic reaction. Thus, the photosensitizing systems based on RB + AP complexes are promising for treating local foci of oncological and non-oncological nature using PDT.