Photoinduced interaction of thionine with phospholipid and cholesterol in artificial membranes

The photoinduced interaction of thionine dye with phosphatidylcholine (PC) (and its components, e.g. lysoPC, phosphorylcholine and choline) and oxidized cholesterol was studied in artificial membranes using spectrophotometric and photoelectrochemical methods. The results show that the dye (electron acceptor) in its singlet excited state forms 1:1 electron donor-acceptor (EDA) complexes with the lipids (electron donor). The electrode kinetics of the photoinduced redox reactions in the cell were also studied to confirm the mechanism of photoinduced interaction between the dye and the lipid.