MEMRI and tumors: a method for the evaluation of the contribution of Mn(II) ions in the extracellular compartment

Eliana Gianolio, Francesca Arena, Enza Di Gregorio, Roberto Pagliarin, Martina Delbianco, Gabriella Baio, Silvio Aime*

*Corresponding author for this work

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The purpose of the work was to set-up a simple method to evaluate the contribution of Mn2+ ions in the intra- and extracellular tumor compartments in a MEMRI experiment. This task has been tackled by silencing the relaxation enhancement arising from Mn2+ ions in the extracellular space. In vitro relaxometric measurements allowed assessment of the sequestering activity of DO2A (1,4,7,10-tetraazacyclododecane-1,7-diacetic acid) towards Mn2+ ions, as the addition of Ca-DO2A to a solution of MnCl2 causes a drop of relaxivity upon the formation of the highly stable and low-relaxivity Mn-DO2A. It has been proved that the sequestering ability of DO2A towards Mn2+ ions is also fully effective in the presence of serum albumin. Moreover, it has been shown that Mn-DO2A does not enter cell membranes, nor does the presence of Ca-DO2A in the extracellular space prompt migration of Mn ions from the intracellular compartment. On this basis the in vivo, instantaneous, drop in SE% (percent signal enhancement) in T-1-weighted images is taken as evidence of the sequestration of extracellular Mn2+ ions upon addition of Ca-DO2A. By applying the method to B16F10 tumor bearing mice, T-1 decrease is readily detected in the tumor region, whereas a negligible change in SE% is observed in kidneys, liver and muscle. The relaxometric MRI results have been validated by ICP-MS measurements. Copyright (c) 2015 John Wiley & Sons, Ltd.

Original languageEnglish
Pages (from-to)1104-1110
Number of pages7
JournalNMR in Biomedicine
Volume28
Issue number9
Early online date14 Jul 2015
DOIs
Publication statusPublished - Sep 2015

Keywords

  • MEMRI
  • cellular and molecular cancer imaging
  • molecular and cellular probes
  • DO2A
  • calcium receptors
  • relaxivity
  • volume fraction
  • manganese(II) complexes
  • breast-cancer
  • relaxometry
  • PH

Cite this

Gianolio, E., Arena, F., Di Gregorio, E., Pagliarin, R., Delbianco, M., Baio, G., & Aime, S. (2015). MEMRI and tumors: a method for the evaluation of the contribution of Mn(II) ions in the extracellular compartment. NMR in Biomedicine, 28(9), 1104-1110. https://doi.org/10.1002/nbm.3349