Highly stable and inert complexation of Indium(III) by reinforced cyclam dipicolinate and a bifunctional derivative for bead encoding in mass cytometry
Grenier, L., Beyler, M., Platas-Iglesias, C. et al.H2cb-te2pa, a cross-bridged cyclam functionalized by two picolinate arms, was used for the formation of an incredible inert In(III) chelate. The inertness of the complex was evaluated by UV-Vis experiments in several competitive media and was highlighted by comparison with [In(dota)]- and [In(dtpa)]2- currently used in biological applications. For the first time a bifunctional analogue of H2cb-te2pa was prepared by C-functionalization to keep its coordination properties intact. However, this strategy leads to the formation of two diastereoisomers, before and after complexation, as evidenced and studied by NMR experiments and DFT calculations. Kinetic studies proved nevertheless that both isomers of the complex are equally inert; they were therefore used without distinction for their covalent grafting on polystyrene beads. The so-called metal-encoded beads were tested for Imaging Mass Cytometry. The detection of 115In allows the generation of images with high quality, proving the great potential of the bifunctional [In(cb-te2pa)]+ derivatives for single-cell analysis by mass cytometry.
Grenier, L., Beyler, M., Platas-Iglesias, C. et al. "Highly stable and inert complexation of Indium(III) by reinforced cyclam dipicolinate and a bifunctional derivative for bead encoding in mass cytometry" Chemistry (2019): doi: 10.1002/chem.201903969