载硫化氢仿生纳泡靶向治疗心肌缺血再灌注损伤的实验研究

It has been proved that the therapeutic gas hydrogen sulfide (H2S) can reduce myocardial ischemia-reperfusion injury (MI/R) through antioxidation, protection of mitochondrial function, inhibition of cardiomyocyte apoptosis and so on. However, how to targetedly deliver H2S to the injured myocardium is the key to avoid its toxicity but obtain its efficacy. Previous studies of our group have found that a large number of platelets aggregated in the area of myocardial injury during early reperfusion. And this phenomenon may be related to the function of platelet membrane. Based on the above, this project proposed to prepare a biomimetic functionalized ultrasonic nanobubble composed of platelet membrane and hydrogen sulfide core to treat MI/R under ultrasound imaging and guiding. The main research contents include: ①Establish a reliable method to prepare biomimetic functional nanobubble, which load sufficient H2S and possess targeting ability like platelet aggregation; ②Detect the targeting ability of nanobubble in vitro and verify its efficacy on hypoxia- Oxygen cardiomyocytes; ③Prepar MI/R in rats, evaluate the efficacy in vivo, and study its therapeutic mechanism and biological toxicity. The implementation of this project will provide a new targeting strategy for therapeutic gas treatment of MI/R.

研究表明，硫化氢（H2S）气体可通过抗氧化、保护线粒体功能、抑制心肌细胞凋亡等途径，显著减少心肌缺血再灌注损伤（MI/R）。然而，如何有效的将H2S靶向传输到损伤心肌局部，是发挥其疗效同时降低毒副作用的关键。本研究前期预试验结果发现，在MI/R发生早期，大量血小板向损伤心肌区靶向聚集，且这种靶向作用可能与血小板膜功能有关。基于此，本项目提出：利用生物仿生技术制备血小板膜包裹、载H2S的仿生功能化超声纳泡，在超声成像监测下介导纳泡破裂，靶向释放H2S以治疗MI/R。主要研究内容包括：①建立仿生功能化纳泡的制备方法，使之搭载足量H2S，并具备血小板的靶向聚集功能；②体外实验检测纳泡的靶向能力，并验证其对缺氧-复氧心肌细胞的保护作用；③制备大鼠MI/R模型，评价纳泡体内疗效，并研究其治疗机制及生物毒性。本项目的实施可为气体治疗心肌缺血再灌注损伤提供新的靶向策略。

心肌缺血再灌注损伤（MI/R）是缺血心肌恢复血流灌注时一种常见的并发症。MI/R会促使心肌细胞进一步死亡，加重心肌梗死，引起更严重的心功能障碍。如何早期诊断MI/R并及时有效干预，对降低心肌损伤和改善患者预后至关重要。.利用MI/R早期血小板在损伤心肌靶向聚集的特性，本项目创新性提出基于血小板膜仿生功能化靶向微泡超声早期检测MI/R的诊断方法，以及基于仿生纳米载体联合硫化氢的靶向治疗方法。主要研究成果包括：①成功制备血小板膜仿生PLGA微泡和载硫化氢前体药二烯丙基三硫化物（DATS）的血小板膜仿生纳米粒，并探明其粒径分布、表面电荷、靶向性、超声成像及载药能力等性质。②建立基于血小板膜仿生PLGA微泡的超声靶向成像方法，超声成像结果与组织病理结果一致，从而实现MI/R的早期无创检测。③实现血小板膜仿生纳米粒靶向递送DATS，靶向释放硫化氢，显著减少心肌ROS产生，保护心功能，显著降低了MI/R程度。相关研究成果发表学术论文13篇，其中SCI收录10篇。IF >10，2篇；IF >5，8篇；单篇最高IF：15.881。获批实用新型专利3项，申请发明专利1项。.本项目利用血小板膜仿生靶向超声造影剂和纳米药物载体，成功实现MI/R早期超声靶向造影成像，和H2S体内靶向递送，显著增强MI/R疗效。本项目为MI/R早期诊断与气体治疗提供新的思路和方法。