靶向血栓MR分子探针的构建及初步鉴定  

Construction and Evaluation of MR Molecular Probes for Targeting Thrombus

作　　者：张瑜[1] 郭大静[1] 周君[1] 郑元义[2] 王志刚[2] 赵建农[1] 

机构地区：[1]重庆医科大学附属第二医院放射科,400010 [2]重庆医科大学附属第二医院超声影像研究所,400010

出　　处：《临床放射学杂志》2012年第8期1178-1182,共5页Journal of Clinical Radiology

基　　金：国家自然科学基金面上项目(编号:81171332);重点项目(编号:81130025);重庆市自然科学基金资助项目(编号:2008BB5233)

摘　　要：目的构建一种靶向血栓MR分子探针并对其相关特性进行鉴定。方法采用双乳化法,以端羧基聚乳酸/羟基乙酸(PLGA-COOH)为载体包裹MR对比剂钆喷酸葡胺(Gd-DTPA)制备Gd-PLGA微球,再采用碳二亚胺法共价结合血小板膜上GPⅡb/Ⅲa受体拮抗剂精氨酸-甘氨酸-天冬氨酸-丝氨酸(Arg-Gly-Asp-Ser,RGDS)短肽片段,构建靶向血栓MR分子探针。观察其理化性质、体外靶向特异性,于1.5 T MRI测量并计算MR纵向弛豫率。结果采用本方法成功构建了靶向血栓MR分子探针,其形态规则,大小较均一,平均粒径为2.04μm,RGDS携带率达89.69%,Gd-DTPA包封率为39.53%;体外寻靶实验显示其对离体血栓具有较强的靶向性及稳定性;在1.5 TMR成像仪上能实现显像,同时随着Gd-DTPA浓度的增加,纵向弛豫率增加。结论成功构建靶向血栓MR分子探针,有望为分子水平诊断血栓提供新技术、新方法。Objective To construct a thrombus-targeted MR molecular probe and to evaluate its related characteristics.Methods Double emulsion solvent evaporation technique was used to encapsulate magnetic resonance contrast agent Gd DTPA in PLGA particles taking PLGA-COOH as the carrier.RGDS peptides were further immobilized by carbodiimide method on the surface of Gd PLGA particles to construct the thrombus-targeted MR molecular probe.The characteristics of the probes were tested and the ability to target thrombus was assessed by in vitro experiment.The longitudinal relaxation rate was measured and calculated by 1.5 T MR scanner.Results The thrombus-targeted MR molecular probe was successfully constructed.The probe had a mean diameter of 2.04 μm.The rate of carrying RGDS peptides was 89.69%.The encapsulation rate of Gd DTPA was 39.53%.In the in vitro experiment,the MR probe had successfully conjuncted to the thrombus.It can be imaged at 1.5 T MR scanner,and at the same time as Gd-DTPA concentration increased,the longitudinal relaxation rate increased.Conclusion The thrombus-targeted MR molecular probeis successfully constructed by this method.It could be helpful to provide a new method to diagnose thrombosis at the molecular level.

关 键 词：聚乳酸/羟基乙酸 RGDS肽 磁共振 血栓 分子探针 

分 类 号：R445.2[医药卫生—影像医学与核医学]