Open AccessUniform mesoporous silica coated iron oxide nanoparticles as a highly efficient, nontoxic MRI T 2 contrast agent with tunable proton relaxivities
Author(s) -
Ye Fei,
Laurent Sophie,
Fornara Andrea,
Astolfi Laura,
Qin Jian,
Roch Alain,
Martini Alessandro,
Toprak Muhammet S.,
Muller Robert N.,
Muhammed Mamoun
Publication year - 2012
Publication title -
contrast media & molecular imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.714
H-Index - 50
eISSN - 1555-4317
pISSN - 1555-4309
DOI - 10.1002/cmmi.1473
Subject(s) - coating , biocompatibility , nanoparticle , mesoporous material , materials science , superparamagnetism , relaxometry , mri contrast agent , mesoporous silica , dispersity , nuclear magnetic resonance , chemical engineering , nanotechnology , magnetic resonance imaging , chemistry , magnetization , organic chemistry , polymer chemistry , catalysis , metallurgy , magnetic field , radiology , physics , quantum mechanics , engineering , medicine , spin echo
Monodisperse mesoporous silica (mSiO 2 ) coated superparamagnetic iron oxide (Fe 3 O 4 @mSiO 2 ) nanoparticles (NPs) have been developed as a potential magnetic resonance imaging (MRI) T 2 contrast agent. To evaluate the effect of surface coating on MRI contrast efficiency, we examined the proton relaxivities of Fe 3 O 4 @mSiO 2 NPs with different coating thicknesses. It was found that the mSiO 2 coating has a significant impact on the efficiency of Fe 3 O 4 NPs for MRI contrast enhancement. The efficiency increases with the thickness of mSiO 2 coating and is much higher than that of the commercial contrast agents. Nuclear magnetic resonance (NMR) relaxometry of Fe 3 O 4 @mSiO 2 further revealed that mSiO 2 coating is partially permeable to water molecules and therefore induces the decrease of longitudinal relaxivity, r 1 . Biocompatibility evaluation of various sized (ca. 35–95 nm) Fe 3 O 4 @mSiO 2 NPs was tested on OC‐k3 cells and the result showed that these particles have no negative impact on cell viability. The enhanced MRI efficiency of Fe 3 O 4 @mSiO 2 highlights these core–shell particles as highly efficient T 2 contrast agents with high biocompatibility. Copyright © 2012 John Wiley & Sons, Ltd.