四肢显微血管吻合术后吻合口血栓形成的可视化研究

四肢显微血管吻合术后吻合口血栓形成常影响组织供血甚至引起肢体坏死，严重时引起肾功衰危及生命。课题组前期首次构建了靶向静脉血栓的光声纳米探针，通过光声成像实现了静脉血栓的早期诊断(ACS Nano 2017)；还分别构建了近红外二窗(NIR-II)探针CQS1000和CQ-4T/HSA，实时监测了循环系统相关的生理病理状态及过程(AFM 2017; AFM 2019)。本项目拟构建首个靶向动脉血栓的NIR-II探针TTQ-Tn6，该探针通过响应新鲜血小板凝块中特有的蛋白二硫键异构酶(PDI)活性，从而靶向动脉血栓关键成分纤维蛋白。在体外对探针进行化学表征、鉴定及体内外生物特性评价等，不断优化探针设计；建立小鼠股动脉血栓模型，应用该探针“点亮”动脉血栓，借助近红外二区成像技术，实现吻合口血栓形成的可视化，为血栓的精准阳性显影诊断、新鲜与陈旧血栓鉴别及动态监测手术取栓或药物溶栓效果提供技术支撑。

Anastomotic site thrombosis after microsurgical vascular anastomosis in extremities usually affects tissue blood supply and even causes limb necrosis. In severe cases, renal failure can be life-threatening. The research group have constructed a photoacoustic nanoprobe targeting venous thrombosis firstly, and achieved the early molecular diagnosis (ACS Nano 2017). Near-infrared second window (NIR-II) probes CQS1000 and CQ-4T/HSA were respectively formulated for real-time monitoring of circulatory system-related physiological and pathological states and processes (AFM 2017; AFM 2019). This project firstly intends to construct a NIR-II probe TTQ-Tn6 which targets arterial thrombus. The probe responds to the enzymatic activity of protein disulfide isomerase (PDI), which is specific in fresh platelets clots, thus targets the fibrin, a key ingredient in arterial thrombosis. To optimize the probe design, in vitro chemical characterization and identification associated with in vitro and in vivo biological characteristics evaluation will respectively be conducted. Mouse femoral arterial thrombosis models will be established, in which the arterial thrombus will be "lighted up" by the probe, and the visualization of anastomotic site thrombosis will be realized by NIR-II imaging, providing technical support for accurate positive imaging diagnosis of thrombosis, identification of fresh and old thrombus, and dynamic monitoring the effect of surgical thrombectomy or thrombolysis.