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

Autor: Akers WJ; Department of Radiology, Washington University School of Medicine, 4525 Scott Avenue, St. Louis, MO 63110, USA., Zhang Z, Berezin M, Ye Y, Agee A, Guo K, Fuhrhop RW, Wickline SA, Lanza GM, Achilefu S
Jazyk: angličtina
Zdroj: Nanomedicine (London, England) [Nanomedicine (Lond)] 2010 Jul; Vol. 5 (5), pp. 715-26.
DOI: 10.2217/nnm.10.38
Abstrakt: 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.
Databáze: MEDLINE