Development and evaluation of a novel VEGFR2-targeted nanoscale ultrasound contrast agents

Recent literatures have reported that the targeted nanoscale ultrasound contrast agents are becoming more and more important in medical application, like ultrasound imaging, detection of perfusion, drug delivery and molecular imaging and so on. In this study, we fabricated an uniform nanoscale bubbles (257 nm with the polydispersity index of 0.458) by incorporation of antibody targeted to vascular endothelial growth factor receptor 2 (VEGFR2) into the nanobubbles membrane by using avidin-biotin interaction. Some fundamental characterizations such as nanobubble suspension, surface morphology, particle size distribution and zeta potential were investigated. The concentration and time-intensity curves (TICs) were obtained with a self-made ultrasound experimental setup in vitro evaluation. In addition, in order to evaluate the contrast enhancement ability and the potential tumor-targeted ability in vivo, normal Wistar rats and nude female BALB/c mice were intravascular administration of the nanobubbles via tail vein injection, respectively. Significant contrast enhancement of ultrasound imaging within liver and tumor were visualized. These experiments demonstrated that the targeted nanobubbles is efficient in ultrasound molecular imaging by enhancement of the contrast effect and have potential capacity for targeted tumor diagnosis and therapy in the future.