Department of Neurosurgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China; Zhejiang Provincial Key Laboratory of Aging and Neurological Disorder Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
Department of Rehabilitation, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200000, China.
Biochem Biophys Res Commun. 2019 Aug 20;516(2):565-570. doi: 10.1016/j.bbrc.2019.06.079. Epub 2019 Jun 22.
Nanoparticle-based thrombolysis is a potential new treatment for stroke. The aim of this study was to investigate the efficacy of targeted thrombolysis using recombinant tissue plasminogen activator (rtPA). The rtPA was covalently bound to magnetic nanoparticles (MNP) and maintained at the target site using an external magnet. Polyacrylic acid (PAA)-coated MNP were synthesized and rtPA was then bound to the resultant PAA-MNP via carbodiimide-mediated amide bonds. For the in vitro tests, blood clots were formed in plastic centrifuge tubes with anti-coagulated plasma, thrombin and calcium chloride. For the in vivo tests, mice with ferric chloride-induced distal middle cerebral artery occlusion were treated with phosphate-buffered saline (PBS), MNP, rtPA, or MNP-rtPA (n = 6 mice per group). The binding efficacy was 80.7 ± 1.5 μg rtPA bound to 1 mg PAA-MNP. In the in vitro tests, the mean lysis percentage dramatically increased from 1.28% in the MNP group without rotation to 77.40% in the rtPA + MNP group with rotating magnetic field. The lysis efficiency of MNP-rtPA was 27.3 ± 1.3%, and it increased to 42.8 ± 2.8% with magnetic field rotation. The mean sizes of the infarct areas of the PBS, MNP, rtPA, and MNP-rtPA mouse groups were 20.09 ± 6.07, 18.28 ± 2.69, 8.65 ± 3.63 and 4.40 ± 2.46 mm, respectively. Thus, targeted MNP-rtPA accelerated thrombolysis and reduced the infarct area in a mouse model of cerebral embolism. This approach may serve as a feasible and effective treatment for embolic cerebral ischemia.
基于纳米颗粒的溶栓治疗是一种治疗中风的新方法。本研究旨在探讨使用重组组织纤溶酶原激活物（rtPA）靶向溶栓的疗效。rtPA 通过碳二亚胺介导的酰胺键共价结合到磁性纳米颗粒（MNP）上，并通过外部磁铁将其保持在靶位。合成了聚丙烯酸（PAA）包覆的 MNP，然后通过碳二亚胺介导的酰胺键将 rtPA 结合到所得的 PAA-MNP 上。在体外试验中，将抗凝血浆、凝血酶和氯化钙在塑料离心管中形成血栓。在体内试验中，用氯化铁诱导的大脑中动脉远端闭塞的小鼠用磷酸盐缓冲盐水（PBS）、MNP、rtPA 或 MNP-rtPA（每组 6 只小鼠）进行治疗。结合效力为 1 毫克 PAA-MNP 结合 80.7 ± 1.5μg rtPA。在体外试验中，在没有旋转的 MNP 组中，平均溶解百分比从 1.28%急剧增加到具有旋转磁场的 rtPA+MNP 组的 77.40%。MNP-rtPA 的溶解效率为 27.3 ± 1.3%，在磁场旋转时增加到 42.8 ± 2.8%。PBS、MNP、rtPA 和 MNP-rtPA 小鼠组的平均梗死面积分别为 20.09 ± 6.07、18.28 ± 2.69、8.65 ± 3.63 和 4.40 ± 2.46mm。因此，靶向 MNP-rtPA 加速了溶栓并减少了栓塞性脑缺血小鼠模型中的梗死面积。这种方法可能成为治疗栓塞性脑缺血的一种可行有效的方法。
