Effect of the surfactant pluronic on the stability of lipid-stabilized perfluorocarbon nanobubbles

摘要

Microbubble (MB) contrast agents are widely used in diagnostic and therapeutic ultrasound (US) applications. However, due to their 1-10 μm size range, MBs have limited use in cancer detection and treatment. To expand contrast enhanced US capabilities, we have developed sub-micron contrast agents, nanobubbles (NB), via the addition of Pluronic, a nonionic triblock copolymer surfactant, to the phospholipid shell stabilizing perfluoropropane (C3F8) gas (Fig 1A). NBs, with diameter of ~200nm, can take advantage of the EPR effect, extravasate the leaky tumor vasculature and accumulate in tumors. Prior work has shown that bubble echogenicity and stability are, in part, dependent on the surface tension of the stabilizing shell. In this study, we evaluate the effect of Pluronic on surface tension of the lipid films and how its presence in the NB shell affects echogenicity and signal decay at clinically-relevant imaging frequencies.