Premium
Enhanced Relaxometric Properties of MRI “Positive” Contrast Agents Confined in Three‐Dimensional Cubic Mesoporous Silica Nanoparticles
Author(s) -
GuilletNicolas Rémy,
Bridot JeanLuc,
Seo Yongbeom,
Fortin MarcAndré,
Kleitz Freddy
Publication year - 2011
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201101766
Subject(s) - materials science , mesoporous silica , paramagnetism , nanoparticle , mesoporous material , porosity , mri contrast agent , context (archaeology) , particle (ecology) , nuclear magnetic resonance , magnetic resonance imaging , nanotechnology , chemistry , organic chemistry , medicine , paleontology , physics , oceanography , radiology , quantum mechanics , geology , composite material , biology , catalysis
Mesoporous silica nanoparticles (MSNs) are of growing interest for the development of novel probes enabling efficient tracking of cells in vivo using magnetic resonance imaging (MRI). The incorporation of Gd 3+ paramagnetic ions into highly porous MSNs is a powerful strategy to synthesize “positive” MRI contrast agents for more quantitative T 1 ‐weighted MR imaging. Within this context, different strategies have been reported to integrate Gd chelates to 2D pore network MSNs. As an alternative, we report on the modulation of the pore network topology through the preparation of a 3D pore network hybrid GdSi x O y MSN system. In this study, 2D GdSi x O y ‐MSNs with similar porosity and particle size were also prepared and the relaxometric performances of both materials, directly compared. Both syntheses lead to water‐dispersible MSNs suspensions (particle size < 200 nm), which were stable for at least 48h. 3D GdSi x O y ‐MSNs provided a significant increase in 1 H longitudinal relaxivity (18.5 s −1 mM −1 ; 4.6 times higher than Gd‐DTPA) and low r 2 /r 1 ratios (1.56) compatible with the requirements of “positive” contrast agents for MRI. These results demonstrate the superiority of a 3D pore network to host paramagnetic atoms for MRI signal enhancement using T 1 ‐weighted imaging. Such an approach minimizes the total amount of paramagnetic element per particle.