Magnetic and Relaxation Properties of Multifunctional Polymer-Based Nanostructured Bioferrofluids as MRI Contrast Agents
authors Amiri, H; Bustamante, R; Millan, A; Silva, NJO; Pinol, R; Gabilondo, L; Palacio, F; Arosio, P; Corti, M; Lascialfari, A
nationality International
author keywords MRI; contrast agents; ferrofluids; relaxometry; multifunctional magnetic nanoparticles
abstract A series of maghemite/polymer composite ferrofluids with variable magnetic core size, which show a good efficiency as MRI contrast agents, are presented. These ferrofluids are biocompatible and can be proposed as possible platforms for multifunctional biomedical applications, as they contain anchoring groups for biofunctionalization, can incorporate fluorescent dyes, and have shown low cellular toxicity. The magnetic properties of the ferrofluids have been determined by means of magnetization and ac susceptibility measurements as a function of temperature and frequency. The NMR dispersion profiles show that the low frequency behavior of the longitudinal relaxivity r(1) is well described by the heuristic model of H-1 nuclear relaxation induced by superparamagnetic nanoparticles proposed by Roch and co-workers. The contrast efficiency parameter, i.e., the nuclear transverse relaxivity r(2), for samples with d > 10 nm assumes values comparable with or better than the ones of commercial samples, the best results obtained in particles with the biggest magnetic core, d 5 15 nm. The contrast efficiency results are confirmed by in vitro MRI experiments at nu = 8.5 MHz, thus allowing us to propose a set of optimal microstructural parameters for multifunctional ferrofluids to be used in MRI medical diagnosis. Magn Reson Med 66:1715-1721, 2011. (C) 2011 Wiley Periodicals, Inc.
issn 0740-3194
year published 2011
volume 66
issue 6
beginning page 1715
ending page 1721
digital object identifier (doi) 10.1002/mrm.22959
web of science category Radiology, Nuclear Medicine & Medical Imaging
subject category Radiology, Nuclear Medicine & Medical Imaging
unique article identifier WOS:000297285000026
  ciceco authors
  impact metrics
journal analysis (jcr 2019):
journal impact factor 3.635
5 year journal impact factor 3.75
category normalized journal impact factor percentile 80.075
dimensions (citation analysis):
altmetrics (social interaction):