Molecular magnetic resonance probe targeting VEGF165: preparation and in vitro and in vivo evaluation

摘要

A new method for imaging the tumor human vascular endothelial growth factor 165 (VEGF 165) is presented. A magnetic resonance imaging (MRI) probe was prepared by crosslinking ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles to the aptamer for tumor vascular endothelial growth factor 165 (VEGF165a??aptamer). The molecular probe was evaluated for its in vitro and in vivo activities toward VEGF165. Enzymea??linked immunosorbent assay showed that the VEGF165a??aptamera??USPIO nanoparticles conjugate specifically binds to VEGF165 in vitro. A cell proliferation test showed that VEGF165a??aptamera??USPIO seems to block the proliferation of human umbilical vein endothelial cells induced by free VEGF165, suggesting that VEGF165 is an effective target of this molecular probe. In xenograft mice carrying liver cancer that expresses VEGF165, T2a??weighted imaging of the tumor displayed marked negative enhancement 3a??h after the intravenous administration of VEGF165a??aptamera??USPIO. The enhancement disappeared 6a??h after administration of the probe. These results suggest the targeted imaging effect of VEGF165a??aptamera??USPIO probe in vivo for VEGF165a??expressing tumors. This is the first report of a targeted MRI molecular probe based on USPIO and VEGF165a??aptamer. Copyright ?? 2014 John Wiley & Sons, Ltd.