tPA nanoconjugate for stroke therapy

用于中风治疗的 tPA 纳米缀合物

基本信息

批准号：
10025188
负责人：
VINOD D LABHASETWAR
金额：
$ 41.35万
依托单位：
CLEVELAND CLINIC LERNER COM-CWRU
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-30 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10025188
关键词：
Acute Alteplase Animals Binding Blood Blood - brain barrier anatomy Blood Vessels Brain Brain hemorrhage Carotid Arteries Cause of Death Cerebrovascular Circulation Characteristics Clinical Coagulation Process Cytolysis Data Development Dose Edema Elderly Encapsulated Environment Event Extravasation FDA approved Fibrinolytic Agents Formulation Goals Half-Life Hemorrhage In Vitro Infarction Inflammation Inflammatory Injections Intravenous Ischemia Ischemic Stroke Kidney Lung Mediating Mediator of activation protein Memory Mitochondria Modeling Morbidity - disease rate Motor Movement Nanoconjugate Natural regeneration Neurologic Neurons Organ Oxidative Stress Phase Play Process Rattus Reactive Oxygen Species Recovery Recovery of Function Reperfusion Injury Reperfusion Therapy Risk Role Sequential Treatment Signal Transduction Slice Stroke Superoxide Dismutase Survival Rate Symptoms Tail Temperature Testing Therapeutic Agents Thrombectomy Thromboembolism Thrombus Time Translations Veins angiogenesis antioxidant enzyme base blood-brain barrier disruption brain repair brain tissue catalase cost design disability effective therapy enzyme activity heart damage improved in vivo intravenous administration intravenous injection ischemic injury migration nano nanoparticle neurogenesis neurological recovery neuron apoptosis neuroprotection neurotoxic neurotoxicity neurovascular novel post stroke prevent protective effect repaired response socioeconomics stem cells stroke model stroke patient stroke therapy thromboembolic stroke thrombolysis

项目摘要

Stroke is a leading cause of death, long-term disability, and socioeconomic costs, highlighting the urgent need for more effective treatments. Intravenous administration of tissue plasminogen activator (tPA) is the only FDA-approved therapy to re-establish cerebral blood flow. But because of increased risk of hemorrhage beyond 4.5 hr post stroke, few stroke patients (<5%) benefit from t-PA. Further, t-PA disrupts the blood-brain barrier integrity (BBB) and is neurotoxic, aggravates reperfusion injury. Reactive oxygen species (ROS), generated soon after ischemia and during reperfusion and thereafter, are considered the main mediators of ischemia/ischemia reperfusion injury. To support this notion, in our previous studies, we showed that sequential treatment with t-PA first, followed by delivery of the antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) encapsulated in nanoparticles (nano-SOD/CAT), both administered via carotid artery 3 hr post ischemia in a thromboembolic rat stroke model, significantly reduced reperfusion injury than did tPA alone. This sequential treatment neutralized elevated ROS levels, inhibited vascular leakage/prevented edema formation, reduced inflammation, and protected neuronal cells from apoptosis. Most important, we found out that the sequential treatment stimulated migration of neuronal and circulating progenitor cells into the infarcted brain, whereas tPA alone inhibited that movement. Based on these promising results, we designed a novel dual-action tPA nanoconjugate – tPA conjugated to nano-SOD/CAT – to achieve neuro and vascular protection from reperfusion injury while retaining the thrombolytic effects of tPA. Our preliminary data show that the tPA nanoconjugate a) has markedly better thrombolytic effects than tPA alone (at 1/4 of the dose of tPA, the conjugate yielded the same degree of thrombolysis), b) causes no tPA-associated neurotoxicity, and c) when given via intravenous (tail vein) injection at 6 hr post stroke, effectively reduces infarct volume, resulting in improved neurological recovery over time and increased survival (~85%), significantly more so than in rats given tPA alone (~20%). We hypothesize that our tPA nanoconjugate, with its sustained neuroprotective effects from oxidative stress and significantly better thrombolytic effects than t-PA alone, could overcome the limitations of tPA alone in minimizing reperfusion injury and achieving neurological/functional recovery, even if treatment is delayed. Ou goal is to investigate and develop our tPA nanoconjugate as a safe and effective treatment for stroke. Specific aims are: AIM 1: To analyze the neuroprotective/thrombolytic effects of the tPA nanoconjugate. AIM 2: To evaluate the extent of neurological recovery and motor functions over time. AIM 3: To confirm the brain repair mechanisms following ischemic/reperfusion injury. An effective treatment could benefit more stroke patients than can be treated with tPA alone because of the extended window of treatment and reduced risk of hemorrhagic complications. Such a therapy could significantly diminish the extent of post-stroke disability.

中风是死亡、长期残疾和社会经济成本的主要原因，凸显了迫切需要更有效的治疗方法：静脉注射组织纤溶酶原激活剂（tPA）。 FDA 批准的唯一一种重建脑血流的疗法，但由于风险增加。中风后 4.5 小时以上发生出血，很少有中风患者 (<5%) 从 t-PA 中受益。此外，t-PA 会扰乱中风。血脑屏障完整性（BBB）并且具有神经毒性，加重活性氧损伤。（ROS），在缺血后不久和再灌注期间及其后产生，被认为是主要的为了支持这一观点，在我们之前的研究中，我们展示了缺血/缺血再灌注损伤的介质。首先用 t-PA 进行序贯治疗，然后输送抗氧化酶、超氧化物歧化酶 (SOD) 和过氧化氢酶 (CAT) 封装在纳米粒子 (nano-SOD/CAT) 中，均通过颈动脉给药在血栓栓塞大鼠中风模型中缺血后 3 小时，再灌注损伤显着减少单独使用 tPA 可以中和升高的 ROS 水平，抑制/预防血管渗漏。最重要的是，我们可以减少水肿形成、减少炎症并保护神经细胞免于凋亡。发现序贯治疗刺激神经和循环祖细胞迁移到基于这些有希望的结果，我们设计了一种新型的双作用 tPA 纳米缀合物（tPA 与纳米 SOD/CAT 缀合），以实现神经和血管免受再灌注损伤的保护，同时保留 tPA 的溶栓作用。我们的初步数据表明，tPA 纳米缀合物 a) 比单独的 tPA 具有明显更好的溶栓效果（tPA 剂量的 1/4，结合物产生相同程度的溶栓作用），b）不会引起与 tPA 相关的神经毒性，c）在中风后 6 小时通过静脉（尾静脉）注射时，可有效减少梗塞体积，从而随着时间的推移改善神经功能恢复并增加存活率 (~85%)，明显高于单独给予 tPA 的大鼠 (~20%)，我们发现我们的 tPA 纳米缀合物具有针对氧化应激的持续神经保护作用，并且显着更好。溶栓效果优于单独使用t-PA，可以克服单独使用tPA的局限性即使治疗被延迟，也能最大限度地减少再灌注损伤并实现神经/功能恢复。我们的目标是研究和开发我们的 tPA 纳米复合物作为一种安全有效的中风治疗方法。目标是：目标 1：分析 tPA 纳米缀合物的神经保护/溶栓作用。目标 2：评估随着时间的推移神经功能恢复和运动功能的程度。目的 3：确认大脑修复。缺血/再灌注损伤后的机制有效的治疗可以使更多的中风患者受益。由于治疗窗口延长并降低了风险，因此与单独使用 tPA 治疗相比这种治疗可以显着减轻中风后残疾的程度。