Macromolecules, Dendrimers, and Nanomaterials in Magnetic Resonance Imaging: The Interplay between Size, Function, and Pharmacokinetics

Macromolecules, dendrimers, and nanomaterials in Magnetic Resonance Imaging (MRI) which is interplay between sizes, function, and pharmacokinetics has been reported. The signal-to-noise ratios in MRI depend on the density of protons present in the region of interest and the degree of polarization of the nuclear spin states. Chelating agents do reduce the number of coordinated water molecules in comparison to the case of free metal ion. A meta-analysis of the controlled studies examining gadolinium agents and the development of NSF suggests a causal relationship. New macromolecular constructs have been added to the arsenal of already well-studied macromolecular and supramolecular platforms. Attempts to push rotational correlation times to their theoretical maximum by increasing molecular weight are all too often compromised either by nonoptimal water residency times, poor solubility in water, or lack of realistic usefulness in the actual intended or hypothesized application.