Fig. 2
Characterization of microbubbles (MBs). (A) Synthesis of MBVEGFR2. (B) Observation of morphology and structure of MBVEGFR2 by scanning electron microscopy (SEM) images: MBCon versus MBVEGFR2; scale = 1 μm. (C) Observation by transmission electron microscopy (TEM) images: MBCon versus MBVEGFR2; scale = 2.5 μm. (D) Observation of MBVEGFR2 by fluorescence microscopy (400 ×; scale bar, 20 μm). The lipid shells of microbubbles were stained with red fluorescent dye DiI. FITC-labeled secondary antibodies were used to trace VEGFR2. (E) Flow cytometry analysis of peptide-linking rate of MBCon and MBVEGFR2. (F) Size distribution by the intensity of MBCon and MBVEGFR2. (G) Box-and-whisker plot of mean diameters of MBCon and MBVEGFR2. (H) Box-and-whisker plot of mean zeta potentials of MBCon and MBVEGFR2. (I) Detailed display about mean diameters, zeta potentials, bubble concentrations and peptide linking rate of MBCon and MBVEGFR2. (J) The stability and imaging ability of MBCon and MBVEGFR2 at 4℃ were determined by micro ultrasound system using an agarose mold. (ns = nonsignificant)