Photosensitizing dyes are used in fluorescence diagnostics and photodynamic therapy (PDT). These usually hematoporphyrin derivatives (HpD) accumulate preferentially within neoplastic tissues. HpD is a mixture of ether and ester linked porphyrins. Its partially purified form is known under the commercial name of photofrin II (PII). PII emission spectra were studied in a hydrophilic (PBS) and a lipophilic (PC liposomes) environment. Red shift was observed in their emission maxima from 615 nm in buffer solution to 635 nm in lipid. Identical red shift was obtained when the intracellular fluorescence of two cancer cell lines, MCF 7 and Jurkat, incubated with PII was investigated. Thus, intramembrane localization of PII may be suggested. As determined from the total fluorescence intensity, the uptake of PII was only slightly higher for Jurkat than for MCF 7 cells. Nevertheless the kinetics of the uptake was found to be different for both cell lines.
The effect of UV radiation on absorption, fluorescence spectra and dynamics of phototransformation of five different humic acids (HA) of natural and synthetic origin were investigated. Two types of synthetic HA were prepared: one containing only C, H and O atoms, and another with content of C, H, O and N atoms. Natural HA were also diversified with respect to their origin. We used UV-C radiation (predominantly the wavelength of 254 nm) to provide a wide spectrum of photochemical mechanisms.