Supramolecular chemistry of anionic boron clusters and its applications in biology

It has been almost 50 years since the term “supramolecular chemistry” was coined to describe chemistry beyond the molecule. Since its beginning, supramolecular chemistry has often been intertwined with biology; noncovalent interactions of biomolecules have been described long before this term was even created. Here, we want to show that supramolecular chemistry and biology can (and should) intertwine more with a slightly forgotten branch of chemistry – the chemistry of boron clusters. The revived interest in boron cluster chemistry is connected with major discoveries in their physicochemical and biological properties. Due to various interaction possibilities, boron clusters can form host–guest complexes with classic hosts such as cyclodextrins and with other biomolecules such as proteins. Boron clusters can also diffuse across biological membranes and be used as membrane carriers for other molecules that normally cannot cross membranes. The properties and chemistry of boron clusters can also be exploited in the synthesis of various nanoparticles (closomers, gold, and polymeric nanoparticles). This article outlines the current and potential usages of boron clusters’ supramolecular properties in biological applications.