In vitro and in vivo investigations on the photodynamic activity of core-modified expanded porphyrin--ammonium salt of 5,10,15,20-tetrakis-(meso-p-sulfonato phenyl)-25,27,29-trithia sapphyrin.

The core modification of expanded porphyrins has been proved to have better photochemical properties, which are favorable for photodynamic therapy (PDT) applications. In this context, this study was aimed to investigate the in vitro and in vivo photodynamic activity of one such core-modified expanded porphyrin, namely, ammonium salt of 5,10,15,20-tetrakis-(meso-p-sulfonato phenyl)-25,27,29-trithia sapphyrin. For the in vitro studies, human erythrocytes were used as a membrane semimodel system to investigate the partitioning ability and drug-uptake characteristics.

Porphyrins in photodynamic therapy - a search for ideal photosensitizers.

The utility of light as a therapeutic agent can be traced back over thousands of years when it was used in Ancient Egypt, India and China to treat a variety of skin diseases like psoriasis, vitiligo, rickets, cancer and psychosis. The isolation of porphyrins and their inherent tumor localizing properties coupled with its ability to generate reactive singlet oxygen when activated by light of particular wavelength which in turn results in cytotoxicity led to the emergence of a new modality namely, photodynamic therapy (PDT) as a therapeutic tool. The higher degree of selectivity offered by this modality and fewer side effects when compared to chemotherapy and radiotherapy has prompted the researchers around the globe to generate new photosensitizers.