载组织型纤溶酶原激活物及精-甘-天-丝氨酸四肽超声微泡造影剂的实验研究  

The Preparation of Ultrasound Microbubbles Carrying Tissue Plasminogen Activator and Arg-Gly-Asp-Ser

作　　者：华兴[1] 高云华[1] 李馨[1] 刘平[1] 谭开彬[1] 刘政[1] 

机构地区：[1]解放军第三军医大学新桥医院超声科,重庆市400037

出　　处：《中国超声医学杂志》2009年第11期1009-1011,共3页Chinese Journal of Ultrasound in Medicine

基　　金：国家自然科学基金(No.30500478)

摘　　要：目的制备一种同时携带组织型纤溶酶原激活物（Tissue plasminogen activator，tPA）与精-甘-天-丝氨酸四肽（RGDS）靶向配体的新型脂质超声微泡造影剂。方法以冷冻干燥法制备包载tPA的脂质超声微泡造影剂并应用共价键桥连剂法结合RGDS配体。光镜及荧光显微镜观察其形态；测量其粒径、表面电位、pH值；以ELISA法测定tPA包封率；流式细胞仪检测RGDS携带率；琼脂糖纤维蛋白平板法检测其纤溶活性；以该造影剂对正常家兔肝脏进行静脉声学造影，绘制时间-强度曲线，检测其成像功能。结果微泡膜上同时携带tPA和RGDS，浓度（7～9）×10^9／ml，粒径（2．08±0．93）μm，表面电位-51．3，pH值5．58，tPA包封率（81．12±12．44）％，RGDS携带率（94．49±6．19）％。微泡在超声辐照条件下显示溶栓活性。声学造影后，该造影剂能明显增强实验兔肝实质回声。结论以冷冻干燥法和共价键桥连剂结合法能成功制备同时包载tPA并携带RGDS的脂质超声微泡造影剂，将为血栓的靶向释药促溶治疗提供一条新的可行之路。Objective To prepare a new kind of ultrasound microbubbles contrast agent carrying tissue plasminogen activator （tPA） and Arg-Gly-Asp-Ser （RGDS） peptide simultaneously. Methods The microbubbles carrying tPA were prepared by lyopyilization, with which RGDS was conjugated by covalent bond thereafter. The microbubbles were examined with microscopy. The diameter, surface potential and pH value were detected. The encapsulation efficiency of tPA was measured by enzyme linked immunosorbent assay （ELISA） . The conjugation rate of RGDS was measured by flow cytometer. The fibrolysis activity of the microbubbles was detected by agarose fibrin plate process. And its echo-enhancing function was evaluated by time intensity curve （TIC） after the contrast of rabbit liver. Results The microbubbles carried tPA and RGDS simultaneously, with the concentration of （7-9） × 10^9/ml, the diameter of （2.08±0.93） t,m, the surface potential of -51.3, the pH of 5.58, the encapsulation efficiency of （81.12±2.44） % and the RGDS conjugation rate of （94.49± 6.19）%. The mierobubbles presented fibrolysis under the exposure of ultrasound. The echos of rabbit livers were enhanced markedly after the ultrasound contrast with the microbubbles. Conclusions The microbubbles carrying tPA and RGDS can be prepared by lyopyilization and covalent bond, which will bring out a new way for the targeting drug-released thrombolysis therapy.

关 键 词：组织型纤溶酶原激活物 精甘-天-丝氨酸四肽 超声波 造影剂 

分 类 号：R943[医药卫生—药剂学]