Amphiphilic polymers in photodynamic therapy

It is shown that some amphiphilic polymers (AP), including, polyvinylpyrrolidone (PVP), which exhibit no their own photochemical activity, can increase the activity of porphyrin photosensitizers (PPS), the most effective and nontoxic types of dyes for photodynamic action on tumor cells. It is also shown that, under the model conditions of tryptophan photooxidation, addition of amphiphilic polymers increases the activity of carborane-substituted tetra(fluorophenyl)porphyrins, Photoditazine, and dimegin. According to NMR and fluorescence spectroscopy data, this phenomenon, known as polymer effect, is probably associated with the formation of AP-PPS complexes, a factor that prevents the aggregation of PPS, normally occurring in aqueous solutions, thereby enhancing the photosensitizing activity of PPS.