MORPHOLOGICAL AND NANOMECHANICAL INVESTIGATIONS OF MAGNEVIST NANO-ENCAPSULATED DENDRIMERS BY ATOMIC FORCE MICROSCOPY

Abstract

Objectives: This research aims at investigating the effect of nano-encapsulating the MagnevistTM, a magnetic resonance imaging agent, within generation four, 1, 4- diaminobutane core polyamidoamine dendrimers on their molecular morphology and their nano-mechanical properties in liquid.Methods: Atomic force microscopy was applied in its imaging and force measuring modes to investigate, on the molecular scale, the morphological and nano-mechanical changes in generation four, 1, 4-diaminobutane core polyamidoamine dendrimers due to the nano-encapsulation of Magnevist in liquid.Results: The weight gain of dendrimers indicates the loading of ~ 30 Magnevist molecules. This has increased the rigidity of the dendrimer molecules, compared to unloaded dendrimers. Atomic force microscopy showed individual well-defined nano-spherical particles with nanoscopic dimensions of (40±13 nm in diameter and 4.38±0.54 nm in height). In contrast, imaging of non encapsulated dendrimers revealed loose aggregates of 15±3.5 nm in diameter and 0.9±0.2 nm in height.Conclusions: The atomic force microscopy, in liquid, was successfully applied to differentiate between Magnevist nano-encapsulated and non-encapsulated dendrimers, in their morphology and in their nano-mechanical properties. The results confirm the nano-encapsulation of Magnevist within generation four, 1,4-diaminobutane core polyamidoamine dendrimers. This loading increased the rigidity of the nanoencapsulated dendrimer, packed ~ 9 Magnevist-G 4 molecules together and may probably enhance the magnetic resonance images and increase their duration of time in the bloodstream when compared with Magnevist alone. Thus elongating the imaging sessions without the need for additional contrast agent doses.