OBJECTIVETo observe the cell binding characteristics of SonoVue microbubbles targeting choriocarcinoma cells and provide evidence for clinical ultrasonic localization of the tumor utilizing the microbubbles.

METHODSThe targeted microbubbles were prepared by conjugating anti-HCG antibody with the SonoVue microbubbles and added in choriocarcinoma cells or endometrial stromal cells to compare the cell binding rate of the agents under optical microscope and with flow cytometry.

RESULTSFlow cytometry demonstrated a binding rate of 77.6% between the SonoVue microbubbles and anti-HCG antibody. Light microscopy showed that the total rosette formation rate of the choriocarcinoma cells exposed to the targeted microbubble bearing anti-HCG antibody reached (87.8-/+6.3)%, significantly higher than that of the endometrial stromal cells [(9.4-/+1.7)%, P<0.05]. The binding rate of the targeted microbubbles with the choriocarcinoma cells before and after PBS washing were (85.4-/+4.7)% and (83.1-/+3.8)% (P>0.05), respectively, suggesting strong stability of the binding. The binding rate was 81.0% according to the results of flow cytometry.

CONCLUSIONThe targeted microbubbles as a contrast agent can efficiently bind to the choriocarcinoma cells in vitro with a stability sufficient to resist the blood flow.