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Nanomedicine (Lond). 2010 Jul;5(5):715-26. doi: 10.2217/nnm.10.38.

Targeting of alpha(nu)beta(3)-integrins expressed on tumor tissue and neovasculature using fluorescent small molecules and nanoparticles.

Author information

1
Department of Radiology, Washington University School of Medicine, 4525 Scott Avenue, St. Louis, MO 63110, USA.

Abstract

AIM:

Receptor-specific small molecules and nanoparticles are widely used in molecular imaging of tumors. Although some studies have described the relative strengths and weaknesses of the two approaches, reports of a direct comparison and analysis of the two strategies are lacking. Herein, we compared the tumor-targeting characteristics of a small near-infrared fluorescent compound (cypate-peptide conjugate) and relatively large perfluorocarbon-based nanoparticles (250 nm diameter) for imaging alpha(nu)beta(3)-integrin receptor expression in tumors.

MATERIALS & METHODS:

Near-infrared fluorescent small molecules and nanoparticles were administered to living mice bearing subcutaneous or intradermal syngeneic tumors and imaged with whole-body and high-resolution optical imaging systems.

RESULTS:

The nanoparticles, designed for vascular constraint, remained within the tumor vasculature while the small integrin-avid ligands diffused into the tissue to target integrin expression on tumor and endothelial cells. Targeted small-molecule and nanoparticle contrast agents preferentially accumulated in tumor tissue with tumor-to-muscle ratios of 8 and 7, respectively, compared with 3 for nontargeted nanoparticles.

CONCLUSION:

Fluorescent small molecular probes demonstrate greater overall early tumor contrast and rapid visualization of tumors, but the vascular-constrained nanoparticles are more selective for detecting cancer-induced angiogenesis. A combination of both imaging agents provides a strategy to image and quantify integrin expression in tumor tissue and tumor-induced neovascular systems.

PMID:
20662643
PMCID:
PMC2914325
DOI:
10.2217/nnm.10.38
[Indexed for MEDLINE]
Free PMC Article

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