Dendritic poly-chelator frameworks for multimeric bioconjugationElectronic supplementary information (ESI) available: Description of syntheses, in vitro evaluation and PET imaging, and additional radiolabelling data. See DOI: 10.1039/c6cc10169k

Starting from multifunctional triazacyclononane-triphosphinate chelator cores, dendritic molecules with the ability to bind metal ions within their framework were synthesized. A cooperative interaction of the chelator cages resulted in a markedly increased affinity towards 67/68 Ga III . A hexameric PSMA inhibitor conjugate with high affinity (IC 50 = 1.2 nM) and favorable in vivo PET imaging properties demonstrated practical applicability. The novel scaffolds are useful for synthesis of structurally well-defined multimodal imaging probes or theranostics. Dendrimers built of chelators show unparalleled Ga(III) complexation efficiency and allow for synthesis of highly symmetrical bifunctional poly-bioconjugates via Click-Chemistry.