BIOMEDICAL APPLICATIONS OF LANTHANIDE(III) TEXAPHYRINS LUTETIUM(III) TEXAPHYRINS AS POTENTIAL PHOTODYNAMIC THERAPY PHOTOSENSITIZERS

The texaphyrins are a novel class of pentadentate, porphyrin-like arom atic macrocyclic ligands that form kinetically stable complexes with e ssentially all cations of the trivalent lanthanide series. This abilit y, combined with certain features inherent to the texaphyrin skeleton, gives rise to species that are of potential interest in a range of me dical applications including diagnosis and therapy. In this paper, the biomedical utility of one particular metallotexaphyrin derivative, na mely the lutetium(III) complex PCI-0123 (1), is highlighted. This Syst em generates singlet oxygen in 11% quantum yield in water (20%-30% in organic solvents) and is an effective sensitizer for photodynamic canc er therapy as judged from animal model studies, It is currently in Pha se I human clinical trials.