Targeted Contrast Agents

Laurent et a/. have designed a new contrast agent to target inflammation. 

1 Intracellular Contrast Agent. Allen and Meade describe a Gd(III)-based MR contrast agent conj ungated to poly arginine that is able to permeate cell membranes. 

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Targeted contrast agents are specific and directed to a specific molecular or cellular target with an appropriate targeting ligand molecule. Recombinant high density lipoprotein (HDL)-like nanoparticles, a specific contrast agent for MRI of atherosclerotic plaques, has been reported [86] (Fig. 25). 

In the context of the development of new contrast agents for medical diagnostic imaging, the nanoparticulate carriers have indeed drawn special attention. These systems allow for an efficient site-specific delivery of targeted contrast agents and, due to their size, provide some relaxivity enhancement with respect to the isolated paramagnetic molecules. 

A.M. Morawski, G.A. Lanza, S.A. Wickline, Targeted contrast agents for magnetic resonance imaging and ultrasound, Curr. Opin. Biotechnol. 16 (2005) 89-92. 

Gupta H, Weissleder R (1996) Targeted contrast agents in MR imaging. Magn Reson Imaging Chn N Am 4 171-184... 

The main botdeneck of molecular imaging for clinical apphcations is the availability of approved targeted contrast agents. Currently, the greatest number of targeted... 

D. Artemov, Molecular magnetic resonance imaging with targeted contrast agents, J. Cell. Biochem. 90 (3) (2003) 518-524. 

Sharma, P. Brown, S. Walter, G. Santra, S. Moudgil, B., Nanoparticles for bioimaging. Advances in Colloid and Interface Science 2006, 123, 471-485. Morawski, A. M. Lanza, G. A. Wickline, S. A., Targeted contrast agents for magnetic resonance imaging and ultrasound. Current Opinion in Biotechnology 2005, 16, (1), 89-92. 

Research is being done to improve the enhancement of the contrast agents used with MRI. Specifically, research involves targeted contrast agents that will bind only to desired tissue at the molecular and cellular level. Visualizing changes at a cellular level would make it possible to detect and diagnose disease sooner and provide opportunities for more focused treatment. 

Wang, Z. J., Boddington, S., Wendland, M. et al. 2008. MR imaging of ovarian tumors using folate-receptor-targeted contrast agents. Pediatr Radiol. 38 529-537. 

D. Artemov, Z.M. Bhujwalla and J.W.M. Bulte, Magnetic Resonance Imaging of Cell Surface Receptors Using Targeted Contrast Agents , p. 485... 

Lauffer RB, Parmelee DJ, Dunham SU, Ouellet HS, Dolan RP, Witte S, McMurty TJ, Walovitch RC. 1998. MS-325 Albumin-targeted contrast agent for MR angiography. Radiology 207 529-538. 

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