Tumor cell uptake and selectivity of gadolinium(III)-phosphonium complexes: The role of delocalisation at the phosphonium centre

The synthesis of bifunctional Gd(III)-phosphonium complexes possessing a varying degree of delocalisation at the phosphonium centre is reported. Cellular uptake studies indicate that a reduced delocalisation at the phosphonium centre can lead to an enhanced Gd uptake into normal cells, resulting in a decrease in the overall tumor cell selectivity.42