Next-generation nanomedicine for acute ischemic stroke

摘要/项目摘要 急性缺血性中风即将迎来一场革命。随着机械血栓切除术在 最严重的血栓都能被移除虽然血栓切除术改善了结局，但大多数治疗 患者仍然有严重的缺陷，这在很大程度上是由于缺血-再灌注损伤引起的继发性损伤。 为了解决这个问题，许多神经保护药物进行了试验，但都失败了，主要是由于药物输送不良 危险的大脑。因此，需要一种新的技术来提供神经保护药物， 脑灌注不足为了迎接这一挑战，宾夕法尼亚大学的NanoMuse将建立在我们的基础上， 最近的两个突破：首先，我们发现纳米尺度的药物载体（纳米载体），结合到 内皮标记物VCAM可以使药物在大脑中的浓度比在没有内皮标记物的情况下递送高30倍。 纳米载体，并且比最好的现有纳米载体好> 6倍。在金标准中风模型的瞬态 在小鼠大脑中动脉闭塞（tMCAO）中，负载皮质类固醇的VCAM-纳米载体 地塞米松改善了死亡率，并使梗死体积减少了32%（超过了 进行临床研究）。第二，我们发现，先前的纳米载体遭受激活的纳米颗粒。 补体蛋白级联，其限制脑中的纳米载体摄取并产生过敏样 降低血压的反应（在中风中非常危险）。因此，我们结合了一个人类 补体抑制剂（因子I）的纳米载体，并完全消除了这些问题。现在我们将 联合收割机并扩展这两项创新，开发我们的产品，一种纳米载体， 神经保护药物在危险大脑中的应用，最初是在缺血性中风患者再灌注后。在目标1中，我们 优化纳米载体（例如，将VCAM靶向部分转换为Fab抗体片段）以最小化 使用小鼠和人血清和白细胞，观察颗粒的补体激活和吞噬作用。在 目的2，我们将使用优化的纳米载体来测试3种药物在tMCAO小鼠模型中的功效： 地塞米松（已经用我们未优化的纳米载体证明有效），或编码两种 抗炎蛋白（我们已经证明在其他小鼠模型中有效）。我们将测量 梗死体积、行为结果、副作用、药物分布和mRNA编码蛋白质产生 与非靶向或无药物的纳米载体相比。最好的单药治疗和联合治疗将是 在高龄患者的tMCAO中得到验证。我们的成果将是一种纳米载体， 在BBB处使用抗炎药，以将梗塞体积改善> 25%。我们的团队准备好了 这一点，与临床医生谁照顾中风，纳米技术专家，商业顾问与多年的经验， 神经重症监护产品和支持性大学。我们将一起帮助迎接中风的下一个 革命

ABSTRACT / PROJECT SUMMARY Acute ischemic stroke is poised for a revolution. With the advent of mechanical thrombectomy in the last decade, the worst clots can be removed. While thrombectomy has improved outcomes, most treated patients still have severe deficits, in large part due to secondary injury caused by ischemia-reperfusion injury. To solve this problem, many neuroprotective drugs were trialed, but all failed, largely due to poor drug delivery to at-risk brain. Therefore, a new technology is needed to deliver neuroprotective drugs to re- and under-perfused brain. To meet this challenge, University of Pennsylvania spin-out NanoMuse will build on our two recent breakthroughs: First, we discovered that nano-scale drug carriers (nanocarriers) that bind to the endothelial marker VCAM can concentrate drugs in the brain >30x higher than if delivered without a nanocarrier, and >6x better than the best prior nanocarrier. In the gold-standard stroke model of transient middle cerebral artery occlusion (tMCAO) in mice, VCAM-nanocarriers loaded with the corticosteroid dexamethasone improved mortality and reduced infarct volume 32% (more than the 25% average of drugs that progressed to clinical studies). Second, we found that prior nanocarriers suffered from activation of the complement protein cascade, which limits nanocarrier uptake in the brain and produces an anaphylaxis-like reaction that drops the blood pressure (very dangerous in stroke). Therefore, we conjugated a human complement-inhibitor (Factor I) to the nanocarriers, and completely eliminated these problems. Now we will combine and extend these two innovations to develop our product, a nanocarrier that massively concentrates neuroprotective drugs in at-risk brain, initially in ischemic stroke patients after reperfusion. In Aim 1, we will optimize the nanocarriers (e.g., switching the VCAM-targeting moiety to an Fab antibody fragment) to minimize complement activation and phagocytosis of the particles, using mouse and human serum and leukocytes. In Aim 2, we will use the optimized nanocarriers to test 3 drugs for efficacy in the tMCAO mouse model: dexamethasone (already proven effective with our un-optimized nanocarrier), or mRNAs encoding two anti-inflammatory proteins (which we already showed were effective in other mouse models). We will measure infarct volume, behavioral outcomes, side effects, drug distribution, and mRNA-encoded protein production compared to untargeted or drug-free nanocarriers. The best mono-therapy and a combination therapy will be validated in tMCAO with advanced age. Our deliverable will be a nanocarrier to concentrates one or two anti-inflammatory drugs at the BBB in order to ameliorate infarct volume by > 25%. Our team is poised to do this, with clinicians who take care of stroke, nanotechnologists, business advisors with years of experience in neuro-critical care products, and a supportive university. Together, we will help usher in stroke’s next revolution.