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。随着机械性血栓摘除术的出现， 在过去的十年里，最严重的血栓可以清除。虽然血栓切除术改善了结果，但大多数患者接受了治疗 患者仍然存在严重的缺陷，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，许多神经保护药物都进行了试验，但都失败了，主要是因为药物传递不佳。 危险中的大脑。因此，需要一种新的技术来提供神经保护药物来重新和 脑供血不足。为了迎接这一挑战，宾夕法尼亚大学的衍生产品NanoMuse将在我们的 最近的两项突破：第一，我们发现结合在细胞表面的纳米级药物载体 血管内皮细胞标志物VCAM可以在大脑中浓缩药物，比没有注射的药物高30倍 纳米载体，比以前最好的纳米载体好6倍。在瞬变的金标准卒中模型中 小鼠大脑中动脉阻塞(TMCAO)，VCAM-纳米载体负载皮质激素 地塞米松可提高死亡率并减少32%的脑梗塞体积(超过平均25%的药物 进展到临床研究)。第二，我们发现以前的纳米载体受到激活的影响 补体蛋白级联，限制脑内纳米载体的摄取并产生类过敏反应 降低血压的反应(在中风中非常危险)。因此，我们把一个人类 补体抑制物(因子I)作用于纳米载体，完全消除了这些问题。现在我们会的 将这两项创新结合起来并加以扩展，以开发我们的产品，一种大量浓缩的纳米载体 高危脑中的神经保护药物，最初用于再灌注后的缺血性中风患者。在目标1中，我们将 优化纳米载体(例如，将VCAM靶向部分切换为Fab抗体片段)以最小化 利用小鼠和人血清和白细胞对颗粒的补体激活和吞噬作用。在……里面 目的2，我们将使用优化的纳米载体在tMCAO小鼠模型中测试3种药物的疗效： 地塞米松(已经被证明对我们的未优化的纳米载体有效)，或编码两个 抗炎蛋白(我们已经证明在其他小鼠模型中有效)。我们将衡量 脑梗塞体积、行为结果、副作用、药物分布和信使核糖核酸编码蛋白的产生 与非靶向或无药物的纳米载体相比。最好的单一疗法和联合疗法将是 在高龄患者的tMCAO中得到验证。我们的交付成果将是一种纳米载体，用于浓缩一到两种 在血脑屏障使用抗炎药物，以使脑梗塞体积减少25%。我们的团队已做好准备 这与治疗中风的临床医生、纳米技术专家、具有多年经验的商业顾问一起 神经危重护理产品，以及一所支持性大学。一起，我们将帮助迎来中风的下一个 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.