University of Torino, Department of Molecular Biotechnology and Health Sciences, via Nizza 52, Torino, Italy.
University of Torino, Department of Molecular Biotechnology and Health Sciences, via Nizza 52, Torino, Italy.
Adv Drug Deliv Rev. 2017 Sep 15;119:61-72. doi: 10.1016/j.addr.2017.08.004. Epub 2017 Aug 9.
Magnetic Resonance Imaging (MRI) enables to provide anatomical, functional and molecular information of pathological angiogenesis when used with properly tailored imaging probes. Functional studies have been the domain of Dynamic Contrast Enhancement (DCE) -MRI protocols from which it is possible to extract quantitative estimations on key parameters such as the volumes of vascular and extracellular compartments and the rates of the bidirectional exchange of the imaging reporters across the endothelial barrier. Whereas paramagnetic Gd-complexes able to reversibly bind to serum albumin act better than the clinically used small-sized, hydrophilic species, new findings suggest that an accurate assessment of the vascular volume is possible by analyzing images acquired upon the i.v. administration of Gd-labelled Red Blood Cells (RBCs). As far as it concerns molecular MRI, among the many available biomarkers, αβ integrins are the most investigated ones. The low expression of these targets makes mandatory the use of nano-sized systems endowed with the proper signal enhancing capabilities. A number of targeted nano-particles have been investigated including micelles, liposomes, iron oxides and perfluorocarbon containing systems. Finally, a growing attention is devoted to the design and testing of "theranostic" agents based on the exploitation of MRI to monitor drug delivery processes and therapeutic outcome.
磁共振成像（MRI）能够提供病理血管生成的解剖学、功能和分子信息，当与适当的成像探针结合使用时。功能研究一直是动态对比增强（DCE）-MRI 协议的领域，从中可以提取有关血管和细胞外腔体积以及成像示踪剂在血管内皮屏障两侧双向交换速率等关键参数的定量估计。虽然能够可逆地与血清白蛋白结合的顺磁 Gd 配合物比临床上使用的小尺寸、亲水性物质效果更好，但新的发现表明，通过分析静脉内给予 Gd 标记的红细胞（RBC）后获得的图像，可以对血管体积进行准确评估。就分子 MRI 而言，在许多可用的生物标志物中，αβ 整合素是研究最多的。这些靶标的低表达使得必须使用具有适当信号增强能力的纳米尺寸系统。已经研究了许多靶向纳米颗粒，包括胶束、脂质体、氧化铁和含全氟碳的系统。最后，人们越来越关注基于 MRI 监测药物输送过程和治疗效果的“治疗诊断”试剂的设计和测试。
