Optical contrast agents

A possible way to improve differentiation between normal and diseased tissues is the use of non-specific contrast agents which achieve contrast enhancement based on morphological and physiological properties of tumour tissue. Contrast agents for X-ray, CT and MRI are preferentially taken up by tumour tissue shortly after intravenous injection due to increased tumour vasculature, leaky endothelial structures and enlarged extracellular volumes [34], a phenomenon that is in principle exploitable for optical contrast agents. 

Table 1 summarizes different modalities, detection principles and clinical indications which are currently at the level of experimental evaluation or in clinical use and employ exogenously administered optical contrast agents. 

Hellebust, A., Richards-Kortum, R. Advances in molecular imaging targeted optical contrast agents for cancer diagnostics. Nanomedicine 7(3), 429445 (2012)... 

Yang, X.M., et al. Photoacoustic tomography of a rat cerebral cortex in vivo with au nanocages as an optical contrast agent. Nano Letters 7(12), 3798-3802 (2007)... 

G. Ku and L. V. Wang, Deeply penetrating photoacoustic tomography in biological tissues enhanced with an optical contrast agent, Ontics letters. 30(5), 507-509 (2005). 

The advent of near-infrared fluorescence (NIRF) molecular imaging, coupled with optical contrast agents or fluorescent probes, has enhanced the sensitivity of in vivo... 

Ghosn B, van de Ven AL, Tam J, Gillenwater A, Sokolov KV, Richards-Kortum R, Roy K (2010) Efficient mucosal delivery of optical contrast agents using imidazole-modified chitosan. J Biomed Opt 15(1) 015003... 

Kumar, S., Aaron, J. and Sokolov, K. (2008) Directional conjugation of antibodies to nanopartides for synthesis of multiplexed optical contrast agents for both delivery and targeting moieties. Nature Protocols, 3, 314-20. 

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