Premium
Intracellular and extracellular T 1 and T 2 relaxivities of magneto‐optical nanoparticles at experimental high fields
Author(s) -
Klug Gert,
Kampf Thomas,
Bloemer Steffen,
Bremicker Johannes,
Ziener Christian H.,
Heymer Andrea,
Gbureck Uwe,
Rommel Eberhard,
Nöth Ulrich,
Schenk Wolfdieter A.,
Jakob Peter M.,
Bauer Wolfgang R.
Publication year - 2010
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.22557
Subject(s) - internalization , extracellular , rhodamine , nanoparticle , analytical chemistry (journal) , chemistry , intracellular , rhodamine b , inductively coupled plasma mass spectrometry , nuclear chemistry , nuclear magnetic resonance , mass spectrometry , materials science , nanotechnology , chromatography , physics , biochemistry , cell , quantum mechanics , photocatalysis , fluorescence , catalysis
This study reports the T 1 and T 2 relaxation rates of rhodamine‐labeled anionic magnetic nanoparticles determined at 7, 11.7, and 17.6 T both in solution and after cellular internalization. Therefore cells were incubated with rhodamine‐labeled anionic magnetic nanoparticles and were prepared at decreasing concentrations. Additionally, rhodamine‐labeled anionic magnetic nanoparticles in solution were used for extracellular measurements. T 1 and T 2 were determined at 7, 11.7, and 17.6 T. T 1 times were determined with an inversion‐recovery snapshot‐flash sequence. T 2 times were obtained from a multispin‐echo sequence. Inductively coupled plasma‐mass spectrometry was used to determine the iron content in all samples, and r 1 and r 2 were subsequently calculated. The results were then compared with cells labeled with AMI‐25 and VSOP C‐200. In solution, the r 1 and r 2 of rhodamine‐labeled anionic magnetic nanoparticles were 4.78/379 (7 T), 3.28/389 (11.7 T), and 2.00/354 (17.6 T). In cells, the r 1 and r 2 were 0.21/56 (7 T), 0.19/37 (11.7 T), and 0.1/23 (17.6 T). This corresponded to an 11‐ to 23‐fold decrease in r 1 and an 8‐ to 15‐fold decrease in r 2 . A decrease in r 1 was observed for AMI‐25 and VSOP C‐200. AMI‐25 and VSOP exhibited a 2‐ to 8‐fold decrease in r 2 . In conclusion, cellular internalization of iron oxide nanoparticles strongly decreased their T 1 and T 2 potency. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.