Targeted PARACEST nanoparticle contrast agent for the detection of fibrin.
A lipid-encapsulated perfluorocarbon nanoparticle molecular imaging contrast agent that utilizes a paramagnetic chemical exchange saturation transfer (PARACEST) chelate is presented. PARACEST agents are ideally suited for molecular imaging applications because one can switch the contrast on and off at will simply by adjusting the pulse sequence parameters. This obviates the need for pre- and postinjection images to define contrast agent binding. Spectroscopy (4.7T) of PARACEST nanoparticles revealed a bound water peak at 52 ppm, in agreement with results from the water-soluble chelate. Imaging of control nanoparticles showed no appreciable contrast, while PARACEST nanoparticles produced >10% signal enhancement. PARACEST nanoparticles were targeted to clots via antifibrin antibodies and produced a contrast-to-noise ratio (CNR) of 10 at the clot surface.
Winter
Patrick M
PM
Department of Medicine, Cardiovascular Division, Washington University, St. Louis, Missouri 63108, USA. patrick@cvu.wustl.edu
Cai
Kejia
K
Chen
Junjie
J
Adair
Christopher R
CR
Kiefer
Garry E
GE
Athey
Phillip S
PS
Gaffney
Patrick J
PJ
Buff
Carolyn E
CE
Robertson
J David
JD
Caruthers
Shelton D
SD
Wickline
Samuel A
SA
Lanza
Gregory M
GM
D003287:Contrast Media / Q000032:analysis / Q000737:chemistry*; D005337:Fibrin / Q000032:analysis* / Q000737:chemistry*; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size
D003287:Contrast Media; D005337:Fibrin