超声微血管成像技术联合载miR-126纳米囊泡早期评估及修复动脉粥样硬化的实验研究

The stability of plaque in atherosclerosis (AS) is closely related to the proliferation degree of new vessels. Many studies focus on the treatment and therapeutic effect assessment of AS. However, there is no ideal method to monitor the neovascularization in plaques yet, and the first-line drug on restraining the growth of new blood vessels in the patients is not effective enough. Targeted microbubbles, which are not only the molecular probes of ultrasound, but also effective carriers of drug or gene , are expected to solve the problems. This project is based on the principle of targeted contrast-enhanced ultrasound and local drugs released by ultrasonic cavitation. Based on successful preparation of nanodroplets (ACS Appl Mater Interfaces. 2015), poly miR-126 nanodroplets are built to study AS plaque both in vitro and in vivo animal models of early targeted imaging and treatment. By using the high-resolution technique of micro-flow imaging, the project is focused on solving: 1) noninvasive quantitative evaluation of the neovascularization in plaques using targeted contrast-enhanced ultrasound and micro-flow imaging; 2) Through synergy of ultrasonic irradiation and targeted microbubbles, miR-126 is released and transfected in target position in the AS plaque to inhibit the new vessel generation. And micro-flow imaging is used to monitor the effect, which attains early diagnosis and treatment and the integration of curative with effect monitoring.

动脉粥样硬化（AS）斑块的稳定性与斑块内新生血管的增生程度密切相关，其治疗及疗效评价是AS研究热点。但目前尚无敏感监测斑块内新生血管的有效方法，且常用药物对患者斑块内新生血管的抑制作用不明显。靶向微泡作为超声分子探针，可携带药物或基因，有望用于解决上述问题。本项目基于靶向超声造影及局部空化微泡释药的原理，在前期成功制备纳米囊泡的基础上（ACS Appl Mater Interfaces 2015），构建负载miR-126的靶向纳米微泡，从体外及体内多层面研究新生血管早期靶向显影及治疗，并利用高分辨率显示微细血管的微血管成像技术（Radiology 2015），重点解决：1）靶向超声造影联合微血管成像早期定量评估斑块内新生血管；2）通过超声辐照与靶向微泡协同作用，实现miR-126的靶向定位释放并促进其转染，抑制新生血管生成；并利用微血管成像进行疗效监测，实现早期诊断和治疗、疗效监测一体化。

动脉粥样硬化（AS）斑块的稳定性与斑块内新生血管的增生程度密切相关，其治疗及疗效评价是AS研究热点。本研究按照计划顺利完成，针对靶向功能显影新生血管及局部靶向miR-126抑制新生血管生成的问题，项目构建了负载miR-126的靶向纳米微泡，对微泡进行了基本特性表征、转染效能、细胞毒性、细胞粘附实验测定；在ApoE基因缺陷小鼠动脉粥样硬化斑块模型上，验证其靶向造影能力，并评估对斑块新生血管的影响。