Contrast agents are widely used to enhance the image quality in clinical imaging using e.g. ultrasound. The contrast agents used for ultrasound imaging are mainly microbubbles (MBs) with a soft or hard shell encapsulating a core of gas. In the present study, MBs with a hard shell of polyvinyl alcohol (PVA), and a core of air were analysed in a capillary electrophoretic system using a UV area imaging detector. The detector was operating at 3 wavelengths; 214 nm, 255 nm and 525 nm, and the highest absorbance for individual PVA-MBs were obtained at 214 nm. Two detection windows and a vertical loop capillary position enabled tracking of the PVA-MBs both in an upward and a downward flow direction, where PVA-MBs had different flow distributions and slightly higher average flow velocity upwards, attributed to temperature differences in the capillary that was part within the instrument and part outside. The tracking also allowed counting and quantification of the PVA-MBs. Separation of PVA-MBs from proteins present in human blood plasma was achieved, with multi-wavelength imaging showing best contrast at 525 nm. The PVA-MBs absolute values of negative zeta potential and anionic mobility when injected from plasma in the pH 12 background electrolyte are higher than those obtained for MBs injected from buffer, consistent with their increased negative charge due to a protein corona coating of the PVA-MBs.

中文翻译：

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紫外区域成像检测器通过毛细管电泳分析聚乙烯醇微气泡的实现。

造影剂被广泛用于增强使用例如超声的临床成像中的图像质量。用于超声成像的造影剂主要是微气泡（MBs），具有包裹气体核的软壳或硬壳。在本研究中，使用紫外面积成像检测器在毛细管电泳系统中分析了具有聚乙烯醇（PVA）硬壳和空气核的MB。探测器工作在3个波长下。分别为214 nm，255 nm和525 nm，并且在214 nm处获得了单个PVA-MB的最高吸光度。两个检测窗口和一个垂直的环形毛细管位置使得能够在向上和向下流动方向上跟踪PVA-MB，其中PVA-MB具有不同的流量分布，并且向上的平均流速稍高，归因于仪器内部和外部的毛细管温度差异。跟踪还允许对PVA-MB进行计数和量化。实现了PVA-MBs与人血浆中蛋白质的分离，多波长成像显示在525 nm处具有最佳对比度。在pH 12背景电解质中从血浆中注入时，负Zeta电位和阴离子迁移率的PVA-MBs绝对值高于从缓冲液中注入的MBs所获得的绝对值，这与由于PVA- MB。多波长成像显示在525 nm处具有最佳对比度。在pH 12背景电解质中从血浆中注入时，负Zeta电位和阴离子迁移率的PVA-MBs绝对值高于从缓冲液中注入的MBs所获得的绝对值，这与由于PVA- MB。多波长成像显示在525 nm处具有最佳对比度。在pH 12背景电解质中从血浆中注入时，负Zeta电位和阴离子迁移率的PVA-MBs绝对值高于从缓冲液中注入的MBs所获得的绝对值，这与由于PVA- MB。