预定位技术用于超声分子成像的体外实验

目的 探讨预定位技术提高超声造影剂靶向肿瘤细胞的能力。方法 采用两步法预定位技术靶向SKOV-3卵巢癌细胞：第一步加入生物素化的CEA抗体，第二步加入结合链霉亲和素的造影剂。结果 制备的结合链霉亲和素的PLGA造影剂平均粒径为（346.20±74.49）nm。链霉亲和素与造影剂的连接效率为（95.02±0.62）%。预定位靶向组细胞结合的造影剂明显多于其余各组。结论 预定位技术能提高造影剂的靶向性，可提高超声分子成像的敏感性。

Study on pretargeting technology for ultrasound molecular imaging in vitro

Objective To evaluate pretargeting technology for improving the ability of targeting tumor cells. Methods Poly (lactic-co-glycolic acid) nanoparticles (NPs) were prepared by double-emulsion method. Streptavidin was covalently bound to the surface of NPs through a carbodiimide reaction. A pretargeting approaches had been studied, first step was added in biotinylated antibodies, and second step was added in streptavidin coated poly (lactic-co-glycolic acid) nanoparticles (SA-NPs). The targeting efficacy of SA-NPs toward SKOV3 cells were determined by laser scanning confocal microscope and flow cytometry. Results The mean size of SA-NPs was (346.20±74.49) nm. The effective binding between NPs and streptavidin was (95.02±0.62)%. In pretargeting group, the number of nanoparticles conjugated to SKOV-3 cells was significantly more than the other group. Conclusion These results indicate that the efficacy of NPs targeting to tumor cells can be increased by this pretargeting method.