Objective    To develop a novel nanoscale ultrasonic contrast agent

perfluorocarbon lipid nanoparticles and to investigate its basic characteristics and capability to enhance ultrasound images when aggregated.     Methods    Perfluorocarbon lipid nanoparticles were prepared by lecithin and liquid perfluorocarbon with a high pressure homogen. The physico-chemical properties of the nanoparticles were detected. Strepavidin was added to the preparation procedure to produce biotinylated perfluorocarbon lipid nanoparticles. Blank nanoparticles with or without biotinylation served as control. The 4 kinds of nanoparticles were used for ultrasound imaging. The aggregation

contrast effect of these agents were studied

and the average gray scale value of the captured ultrasound images were analyzed by the DFY software.     Results    These nanoparticles were uniform and stable

and with a mean size of (171.9±91.0) nm. There was no visible ultrasound signals scattered with the nanoparticles before adding strepavidin

while obviously ultrasound echo signals were observed in those biotinylated nanoparticles

with significant difference between the ultrasound images before/after biotinylation.     Conclusion    A steady perfluorocarbon lipid nanoparticles are prepared

and can aggregate together in the existence of strepavidin and enhance the ultrasound image. The aggregated nanoparticles might be regarded as a ultrasound contrast agent.