本实验制备了同时包裹气体和Fe3O4纳米颗粒的复乳微气泡。采用复乳的制备方法，该微气泡结构首先是聚乳酸（PLA）和疏水的Fe3O4纳米颗粒溶解后形成油相，在同时通入N2的情况下超声声振形成W/O层的初乳微气泡，然后将上述初乳微气泡转移至1％聚乙烯醇（PVA）溶液中形成（W/O）/W的复乳。该复乳微气泡进行体外超声显影对比实验，结果表明，同时包裹气体合Fe3O4纳米颗粒的微气泡具有最强的超声显影效果。
In this study, we synthesized multilayer emulsion microbubbles structure containing SPIO Fe3O4 nanoparticles in the oil layer and a N2 gas core. The diameter of microbubble can be controlled by the reaction conditions, resulting in particles with diameters of approximately 2μm～8μm. The microstructure may be useful to enhance the sensitivity of ultrasound imaging. The utilization of Fe3O4/ PLA /N2 multiple emulsion stable microbubbles will be applicable to intravascular ultrasound imaging. Combining SPIO Fe3O4 nanoparticles with ultrasound imaging technique may be more attractive in ultrasound molecular imaging and also may provide a dramatic increase in resolution over conventional clinical diagnostic ultrasound scanners.
Fig.1. Schematic diagram of multiple emulsion microbubble design
F. Yang et al., Multiple emulsion microbubbles for ultrasound imaging, Mater. Lett. (2007), doi:10.1016/j.matlet.2007.04.111
