Fig 1.
Morphologic characterization and size distribution of RGD-MBs.
(a) Representative microscopic image of RGD-MBs (bar = 10 μm). (b) Typical size distribution of RGD-MBs.
Fig 2.
Binding specificity of RGD-MBs.
Static binding assay on bEnd.3 cells or αvβ3-negative MCF-7 cells was performed with and without pre incubation with anti-alpha(v) antibodies (×200). (a) Non-targeted control MBs (1×108 particles/mL). (b) 1×106, (c) 1×107, (d) 1×108, and (e) 1×109 particles/mL RGD-MBs. (f) RGD-MBs (1×108 particles/mL) incubated with αvβ3-negative MCF-7 cells. (g-i) RGD-MBs (1×108 particles/mL) with (g)1 ug/ml, (h) 5 ug/ml, and (i) 25 ug/ml anti-alpha(v) antibodies. (j) Quantitative analysis of the number of attached bubbles per field; (k) Quantitative analysis of the number of attached bubbles per cell. (* P < 0.05, ** P < 0.01).
Table 1.
Adhesion of different types of microbubbles to bEnd.3 cells or αvβ3-negative MCF-7 cells with and without pre incubation with anti-alpha(v) antibodies.
Fig 3.
Transverse color-coded ultrasonography after intravenous administration of RGD-MBs obtained at three different tumor stages of subcutaneous Hep-2 tumor xenografts.
(a) Small tumor (50–150 mm3). (b) Medium tumor (151–250 mm3). (c) Large tumor (> 250 mm3). Green represents targeted ultrasound signals from adherent RGD-MBs. (d) Quantitative analysis revealed ultrasound imaging signal intensity was highest in the small tumor group (** P < 0.01).
Fig 4.
Immunofluorescence staining for αν integrin expression on Hep-2 tumor slices.
(a) Small tumor. (b) Medium tumor. (c) Large tumor. Green represents tumor blood vessels; blue represents nuclei stained with DAPI staining (bar = 100 μm).