In vitro and in vivo trackable titanocene-based complexes using optical imaging or SPECT.

A novel Ti/111In-heterometallic radiotheranostic along with non-radioactive Ti/In, Ti/Lu, and Ti/Y analogues has been reported, thanks to the design of a challenging synthesis of the first titanocene-DOTA ligand. The corresponding titanocene-BODIPY complex was developed for in vitro tracking by optical imaging. The different complexes were characterized and their antiproliferative properties were evaluated on three cancer cell lines (A2780, B16F1, and PC3). As a proof of concept, initial studies in healthy mice were performed with a Ti/111In derivative to obtain information about its uptake, its biodistribution, and its excretion. Confocal microscopy experiments were performed with fluorescent complexes to track it in vitro.