Geometrical confinement of gadolinium-based contrast agents in nanoporous particles enhances T1 contrast.
Magnetic resonance imaging contrast agents are currently designed by modifying their structural and physiochemical properties to improve relaxivity and to enhance image contrast. Here, we show a general method for increasing relaxivity by confining contrast agents inside the nanoporous structure of silicon particles. Magnevist, gadofullerenes and gadonanotubes were loaded inside the pores of quasi-hemispherical and discoidal particles. For all combinations of nanoconstructs, a boost in longitudinal proton relaxivity r(1) was observed: Magnevist, r(1) ≈ 14 mM(-1) s(-1)/Gd(3+) ion (∼ 8.15 × 10(+7) mM(-1) s(-1)/construct); gadofullerenes, r(1) ≈ 200 mM(-1) s(-1)/Gd(3+) ion (∼ 7 × 10(+9) mM(-1) s(-1)/construct); gadonanotubes, r(1) ≈ 150 mM(-1) s(-1)/Gd(3+) ion (∼ 2 × 10(+9) mM(-1) s(-1)/construct). These relaxivity values are about 4 to 50 times larger than those of clinically available gadolinium-based agents (∼ 4 mM(-1) s(-1)/Gd(3+) ion). The enhancement in contrast is attributed to the geometrical confinement of the agents, which influences the paramagnetic behaviour of the Gd(3+) ions. Thus, nanoscale confinement offers a new and general strategy for enhancing the contrast of gadolinium-based contrast agents.
Department of Chemistry, Smalley Institute for Nanoscale Science and Technology, Center for Biological and Environmental Nanotechnology, Rice University, Houston, Texas 77251-1892, USA.
Jeyarama S
JS
Ananta
Biana
B
Godin
Richa
R
Sethi
Loick
L
Moriggi
Xuewu
X
Liu
Rita E
RE
Serda
Ramkumar
R
Krishnamurthy
Raja
R
Muthupillai
Robert D
RD
Bolskar
Lothar
L
Helm
Mauro
M
Ferrari
Lon J
LJ
Wilson
Paolo
P
Decuzzi
D003287:Contrast Media / Q000737:chemistry*; D005682:Gadolinium / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D053758:Nanoparticles / Q000737:chemistry*; D058608:Nanopores / Q000648:ultrastructure*; D010316:Particle Size
D003287:Contrast Media; D005682:Gadolinium