PlumX Metrics
Embed PlumX Metrics

Developing High Field MRI Contrast Agents by Tuning the Rotational Dynamics: Bisaqua GdAAZTA-based Dendrimers

Israel Journal of Chemistry, ISSN: 1869-5868, Vol: 57, Issue: 9, Page: 887-895
2017
  • 14
    Citations
  • 0
    Usage
  • 10
    Captures
  • 0
    Mentions
  • 0
    Social Media
Metric Options:   Counts1 Year3 Year

Metrics Details

  • Citations
    14
    • Citation Indexes
      14
  • Captures
    10

Article Description

Monomeric and dimeric AAZTA-based bifunctional chelators (AAZTA=6-amino-6-methylperhydro-1,4-diazepine tetraacetic acid) were attached to different generations (G0, G1 and G2) of ethylenediamine-cored PAMAM dendrimers (PAMAM=polyamidoamine) to obtain a series of six dendrimeric systems with 4 to 32 chelates at the periphery. These Gd-loaded dendrimers have molecular weight ranging from 3.5 to 25 kDa, thus allowing a systematic investigation on the changes in relaxivity (r) with the variation of the rotational dynamics following the increase in molecular size. Variable-temperature O NMR (on the dimeric building block GdL2) and H Nuclear Magnetic Relaxation Dispersion measurements at different temperatures indicate that the water exchange lifetime (τ∼90 ns) of the two inner sphere water molecules does not represent a limiting factor to the relaxivity of the systems. The r values at 1.5 T (60 MHz) and 298 K increases from 10.2 mM s for the monomer GdL1 to 31.4 mM s for the dendrimer GdG2-32 (+308 %). However, the relaxivity (per Gd) does not show a linear dependence on the molecular mass, but rather the enhancement tends to attenuate markedly for larger systems. This effect has been attributed to the growing decrease in correlation between local rotational motions and global molecular tumbling.

Bibliographic Details

Provide Feedback

Have ideas for a new metric? Would you like to see something else here?Let us know