Aquatic self-assembly of sixteen subunits into a 39-kDa dendrimer.

We have developed the 8-(m-acetylphenyl)-2'-deoxyguanosine (mAG) scaffold for the self-assembly of supramolecules in water and for the synthesis of self-assembled dendrimers (SADs) in organic media. Previously, reported mAG assemblies showed promising characteristics for the construction of SADs. Yet, none of these SADs had large enough dendrons to reach a fractal geometry characteristic of high-generation dendrimers. Here we present the synthesis as well as the molecular and supramolecular characterization of a fourth-generation hydrophilic self-assembled hexadecameric dendrimer [mAGD(4)(OH)(16)](16)·3KI (3(16)) with a size and shape akin to those of globular proteins. The diameter of 3(16) (5.0 nm) was measured by pulsed field gradient NMR and dynamic light scattering experiments, which enabled the construction of a computer-generated molecular model. This SAD represents an attractive platform for biomedical applications due to its water solubility, discreteness, well-defined structure, thermal stability (T(m) = 68 °C), and functional core.