RGD靶向微泡造影剂的制备及其黏附效能  

Preparation of RGD-targeted Microbubble Contrast Agent and Its Adhesion Efficacy

作　　者：徐秀霞[1] 宋竹清 徐健蓉[1] 胡巧[3] 

机构地区：[1]西南科技大学生命科学与工程学院,四川绵阳621010 [2]北京大学深圳医院,广东深圳518036 [3]广西壮族自治区人民医院超声科,广西南宁530021

出　　处：《中国医学影像学杂志》2015年第2期87-90,共4页Chinese Journal of Medical Imaging

基　　金：国家自然科学基金项目(81260223)

摘　　要：目的制备一种新型的RGD超声微泡造影剂,探讨其在体外与小鼠血管内皮细胞(b End.3)靶向黏附效果,为肿瘤血管新生超声分子成像奠定基础。材料与方法以"生物素-亲和素"体系制备出RGD靶向微泡造影剂,分为10μg/ml RGD肽封闭组和30μg/ml RGD肽封闭组,未携带RGD肽微泡造影剂作为空白对照。粒径分析仪、普通光镜下进行表征或检测。体外培养小鼠血管内皮细胞,采用多肽封闭静态黏附实验验证靶向性和黏附效率;应用平行板流动腔芯片,设置不同流体剪切力,观察RGD靶向微泡造影剂在血管内皮细胞表面的动态黏附效果。结果测得的RGD靶向微泡粒径为(4.09±0.07)μm。单个细胞表面黏附的微泡个数RGD肽封闭组与RGD-MBs组比较,10μg/ml RGD肽封闭组为(2.98±0.35)个(P<0.05),30μg/ml RGD肽封闭组为(1.78±0.23)个(P<0.001)。10μg/ml和30μg/ml RGD肽封闭实验表明,黏附在单个细胞表面的微泡数量分别降低54.64%和67.00%。在剪切应力1.5 dyne/cm2下,RGD靶向微泡在细胞表面黏附率随着剪切应力增大而增加(P<0.05)。当剪切应力为1.5 dyne/cm2时,RGD靶向微泡在细胞表面黏附率为(48.72±4.26)个,继续增大剪切应力,黏附率降低(P<0.05)。结论 RGD靶向微泡造影剂能特异性地黏附血管内皮细胞,有望作为超声分子探针检测评价整合素ανβ3在肿瘤血管新生中的表达,用于肿瘤的早期诊断及预后检测。PurposeTo develop a novel RGD microbubbles （RGD-MBs） and to evaluate the targeted binding effect with endothelial cells in vitro.Materials and MethodsThe RGD peptide was coated onto the microbubbles through biotin-avidin linkage including 10 μg/ml and 30 μg/ml groups. The microbubbles not carrying RGD peptide were obtained as negative control. Blocking studies were performed with pre-incubation of the cells with RGD peptide for 2 hours. The microbubbleswere characterized by Accusizer 780 and optical microscope. The binding specificity of RGD-MBs withανβ3-expressing mouse endothelial cells was determined with competitive inhibition experiments in vitro. The attachment study was performed using parallel plate flow chamber to investigate the dynamic adhesion on endothelial cells at various shear stresses.ResultsThe RGD-MBs had an average diameter of （4.09±0.07） μm. The binding RGD-MBs per cell were 2.98±0.35 for 10 μg/ml RGD and 1.78±0.23 for 30 μg/ml RGD. RGD-MBs binding to mouse endothelial cells decreased 54.64% and 67.00% in the presence of RGD peptide at a concentration of 10 μg/ml and 30 μg/ml respectively. When the shear stress was under 1.5 dyne/cm2, the accumulation rate was increased with the increase of shear stress （P〈0.05）. Accumulation rate reached the maximum （48.72±4.26） RGD-MBs/min at wall share stress of 1.5 dyne/cm2, and decreased as sheer stress 〉1.5 dyne/cm2 （P〈0.05）. Conclusion The RGD-MBs can specifically bind to endothelial cells, indicating its usefulness as ultrasonic molecular probe in monitoring integrinανβ3 expression during tumor angiogenesis, and is potentially valuable for in tumor early-staging and prognosis.

关 键 词：超声检查 造影剂 微泡 RGD肽 内皮细胞 新生血管化 病理性 整合素ΑΝΒ3 体外研究 小鼠 

分 类 号：R445.1[医药卫生—影像医学与核医学]