Cellular Uptake and Photo-Cytotoxicity of a Gadolinium(III)-DOTA-Naphthalimide Complex "Clicked" to a Lipidated Tat Peptide

William O'Malley, Riccardo Rubbiani, Margaret Aulsebrook, Michael Grace, Leone Spiccia, Kellie Tuck, Gilles Gasser, Bim Graham
2016
A new bifunctional macrocyclic chelator featuring a conjugatable alkynyl-naphthalimide fluorophore pendant group has been prepared and its Gd(III) complex coupled to a cell-penetrating lipidated azido-Tat peptide derivative using Cu(I)-catalysed "click" chemistry. The resulting fluorescent conjugate is able to enter CAL-33 tongue squamous carcinoma cells, as revealed by confocal microscopy, producing a very modest anti-proliferative effect (IC50 = 93 µM). Due to the photo-reactivity of the
more » ... ctivity of the naphthalimide moiety, however, the conjugate's cytotoxicity is significantly enhanced (IC50 = 16 µM) upon brief low-power UV-A irradiation.
doi:10.5167/uzh-134636 fatcat:6ojwv74omrdptat3vgh7sjpvfa