Abstract:

Objective To prepare the poly(lactic-co-glycolic acid)(PLGA) dual-targeted ultrasound contrast agent carrying anti-human epidermal growth factor receptor 2 (anti-HER2) and anti-vascular endothelial growth factor receptor 2 (anti-VEGFR2) antibodies and observe the targeting ability and the effect of ultrasound imaging in vitro. Methods The PLGA nanoparticles (NPs) were prepared by a modified double emulsious-solvent evaporation technique and the general characteristics of PLGA NPs were analyzed by the transmission electron microscope and laser particle size analyzer. The anti-HER2 and anti-VEGFR2 antibodies were conjugated to PLGA NPs by the carbodiimide method to prepare the dual-targeted polymer nanoparticle ultrasound contrast agent carrying both anti-HER2 and anti-VEGFR2 antibodies. The targeting ability in vitro was assessed by the laser scanning confocal microscope (LSCM) and the rate of combination with target cells was detected by flow cytometer. The effect of imaging in vitro was observed by the high frequency ultrasonography. Results The PLGA NPs were round with smooth surface, good dispersion, and hollow structure. The average particle size was (152.00±58.08) nm. The results of targeting tests in vitro showed that the PLGA dual-targeted NPs carrying anti-HER2 and anti-VEGFR2 antibodies were firmly attached to the surface of human breast cancer cells SKBR3 and endothelial cells of angiosarcoma SVEN1 ras (SVR). The results of ultrasonic imaging tests in vitro indicated that the PLGA dual-targeted nanoparticle ultrasound contrast agent presented uniform and fine dotted dense high echo with no attenuated echo in the rear area.  Conclusion The PLGA dual-targeted nanoparticle polymer ultrasound contrast agent carrying both anti-HER2 and anti-VEGFR2 antibodies is successfully prepared. This contrast agent can specifically bind to SKBR3 cells with high expression of HER2 and SVR cells with high expression of VEGFR2 in vitro. The effect of ultrasound imaging in vitro is satisfactory.

Key words: poly(lactic-co-glycolic acid), targeted ultrasound contrast agent, human epidermal growth factor receptor 2, vascular endothelial growth factor receptor 2