A Novel Nanobubble Contrast Agent: Preparation And Eveluation

Ultrasound Contrast Agents (UCAs) are intravenous agents used to enhance theultrasound imaging effect in tumor diagnosis. Current clinical UCAs are microbubbleswith size between1~4μm. Due to the micrometer, microbubble UCAs are limited tointravascular imaging. Recently, more and more nano-scale UCAs have showed uniqueadvantages with sub-micrometer size with EPR effects and thus have great potential as anovel tumor diagnostic contrast agent.In this thesis, a novel nanobubble contrast agent is synthesized. The physiochemicalproperties are characterized and used to optimize the synthetic condition. Including:(1) Various components for nanobubbles have been tested and optimized as well asthe preparation condition. It was found that the formula:2%HES,0.1%Tween60,0.375%Ascorbyl Palmitate,0.005%low molecular weight chitosan and0.005%Hexadecanediol produced nanobubbles between300~800nm.(2) Stable nanobubbles were produced with modifier BS(PEG)5, which significantlyincrease the half life of the nanobubbles, as well as ultrasound imaging ability in vitro.(3) A dual Fluorescence-Ultrasound nanobubbles contrast agent was prepared withnear-infrared fluorescence dye cyanine5.5.(4) The prepared nanobubbles solution exhibited ultrasonic contrast enhancementbetter than that of microbubbles.