Encapsulated or Not Encapsulated? Ammonium Salts Can Be Encapsulated in Hexameric Capsules of Pyrogallol[4]arene.

Tetraalkylammonium salts were found, contrary to literature reports, to be encapsulated into hexameric capsules of pyrogallol[4]arene in benzene solution. The guest affinity depended on the length of the alkyl chain, the counteranion, the solvent used, the ammonium concentration, and most importantly, the pyrogallol[4]arene to ammonium salt ratio. At high ammonium salt to pyrogallol[4]arene ratios no encapsulation was observed, presumably since the high salt destabilized the formed hexamers.

Alginate-coated magnetic nanoparticles for noninvasive MRI of extracellular calcium.

Nanoparticles (NPs) have great potential to increase the diagnostic capacity of many imaging modalities. MRI is currently regarded as the method of choice for the imaging of deep tissues, and metal ions, such as calcium ions (Ca(2+)), are essential ingredients for life. Despite the tremendous importance of Ca(2+) for the well-being of living systems, the noninvasive determination of the changes in Ca(2+) levels in general, and extracellular Ca(2+) levels in particular, in deep tissues remains a challenge.

Magnetic nanoparticles-based diagnostics and theranostics.

In recent years, enormous efforts have been made to translate nanotechnology innovations into medical practice. The main focuses were diagnosis and therapy with recent emphasis on multi-modal imaging. Since in many instance the sites for imaging and therapy are the same it became apparent that targeted magnetic nanoparticles (MNPs), which can be imaged, can also be used as a platform for theranostics applications.