Dendrimer-encapsulated rhenium cluster complexes

The extreme versatility of dendrimers makes them attractive for drug delivery applications. In this perspective, binding of potential drug molecules non-covalently at the interior of dendritic hosts seems to be the most appropriated strategy. We have established glycodendrimers with dense maltose shell which may be utilized to encapsulate nanometer sized guest molecules. ^[1] This is of particular interest since it has been shown that polynuclear cluster compounds have antitumoral as well as antiviral properties. ^[2]

The encapsulation and release of an anionic rhenium cluster complex [Re₆S₈(OH)₆]^{4- [3]} in biocompatible maltose-decorated dendrimers (generation 4 and 5) have been studied in detail applying different physico-chemical methods, e.g. UV/vis, time-resolved laser-induced fluorescence spectroscopy, laser induced liquid bead ion desorption mass spectrometry and dynamic light scattering measurements. On average, 4 – 5 cluster anions can be captured in the interior of sugar-coated dendrimers, and a slow release of cluster complexes was observed under physiological conditions.

The encapsulation and release properties of maltose-decorated nanocarriers imply the possibility for the development of the next generation dendritic hosts with targeting moieties.

Literature:

[1] B. Klajnert et al., Chem. Eur. J. 2008, 14, 7030. [2] J. T. Rhule et al., Chem. Rev. 1998, 98, 327. [3] K. A. Brylev et al., Inorg. Chem. 2007, 46, 7414.