TY - JOUR
T1 - Gd-DTPA-dopamine-bisphytanyl amphiphile : synthesis, characterisation and relaxation parameters of the nanoassemblies and their potential as MRI contrast agents
AU - Gupta, Abhishek
AU - Willis, Scott A.
AU - Waddington, Lynne J.
AU - Stait-Gardner, Tim
AU - Campo, Liliana de
AU - Hwang, Dennis W.
AU - Kirby, Nigel
AU - Price, William S.
AU - Moghaddam, Minoo J.
N1 - Publisher Copyright:
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2015/9/1
Y1 - 2015/9/1
N2 - Here, a new amphiphilic magnetic resonance imaging (MRI) contrast agent, a GdIII-chelated diethylenetriaminepentaacetic acid conjugated to two branched alkyl chains via a dopamine spacer, Gd-DTPA-dopamine-bisphytanyl (Gd-DTPA-Dop-Phy), which is readily capable of self-assembling into liposomal nanoassemblies upon dispersion in an aqueous solution, is reported. In vitro relaxivities of the dispersions were found to be much higher than Magnevist, a commercially available contrast agent, at 0.47 T but comparable at 9.40 T. Analysis of variable temperature 17O NMR transverse relaxation measurements revealed the water exchange of the nanoassemblies to be faster than that previously reported for paramagnetic liposomes. Molecular reorientation dynamics were probed by 1H NMRD profiles using a classical inner and outer sphere relaxation model and a Lipari-Szabo "model-free" approach. High payloads of GdIII ions in the liposomal nanoassemblies made solely from the Gd-DTPA-Dop-Phy amphiphiles, in combination with slow molecular reorientation and fast water exchange makes this novel amphiphile a suitable candidate to be investigated as an advanced MRI contrast agent. Heads up: Liposomal nanoassemblies, made solely from the novel paramagnetic amphiphile with two branched chains (Gd-DTPA-Dop-Phy), have high potential as advanced magnetic resonance imaging (MRI) contrast agents due to the high payloads of GdIII ions they offer, along with their slow molecular reorientation and fast water exchange.
AB - Here, a new amphiphilic magnetic resonance imaging (MRI) contrast agent, a GdIII-chelated diethylenetriaminepentaacetic acid conjugated to two branched alkyl chains via a dopamine spacer, Gd-DTPA-dopamine-bisphytanyl (Gd-DTPA-Dop-Phy), which is readily capable of self-assembling into liposomal nanoassemblies upon dispersion in an aqueous solution, is reported. In vitro relaxivities of the dispersions were found to be much higher than Magnevist, a commercially available contrast agent, at 0.47 T but comparable at 9.40 T. Analysis of variable temperature 17O NMR transverse relaxation measurements revealed the water exchange of the nanoassemblies to be faster than that previously reported for paramagnetic liposomes. Molecular reorientation dynamics were probed by 1H NMRD profiles using a classical inner and outer sphere relaxation model and a Lipari-Szabo "model-free" approach. High payloads of GdIII ions in the liposomal nanoassemblies made solely from the Gd-DTPA-Dop-Phy amphiphiles, in combination with slow molecular reorientation and fast water exchange makes this novel amphiphile a suitable candidate to be investigated as an advanced MRI contrast agent. Heads up: Liposomal nanoassemblies, made solely from the novel paramagnetic amphiphile with two branched chains (Gd-DTPA-Dop-Phy), have high potential as advanced magnetic resonance imaging (MRI) contrast agents due to the high payloads of GdIII ions they offer, along with their slow molecular reorientation and fast water exchange.
KW - contrast media (diagnostic imaging)
KW - magnetic resonance imaging
KW - nuclear magnetic resonance spectroscopy
UR - http://handle.uws.edu.au:8081/1959.7/uws:32202
U2 - 10.1002/chem.201501905
DO - 10.1002/chem.201501905
M3 - Article
SN - 0947-6539
VL - 21
SP - 13950
EP - 13960
JO - Chemistry: A European Journal
JF - Chemistry: A European Journal
IS - 40
ER -