Ishii K1, Takayanagi A, Shimizu S, Abe H, Sogawa K, Kobayashi N.
Free Radic Biol Med. 2005 Apr 1;38(7):920-7.In this paper, we have investigated the ability to sensitize the phototoxicity toward HeLa cells in vitro, of tetra-tert-butylphthalocyaninatosilicon (SiPc) covalently linked to one or two 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) radicals (R1c or R2c), which are shown as photosensitizers efficiently producing singlet oxygen (1Delta(g)). Addition of R1c or R2c encapsulated in liposomes to cultures, followed by irradiation with a 680-nm dye laser, resulted in a highly significant phototoxicity toward HeLa cells, in contrast to negligible phototoxicity observed with (dihydroxy)SiPc (R0). Read More