Novel nanoparticles function as chemo- and adjunctive-therapy against experimental cerebral malaria

神经功能障碍是血液期恶性疟原虫（Pf）感染的重要并发症， 这种综合征被称为脑型疟疾（CM）。我们开发了人血清白蛋白（HSA）纳米颗粒 (NPs)其是白蛋白的纳米级聚集体，作为药物递送和缀合的抗血液阶段的载体， 疟原虫药物，包括蒿甲醚（A）和青蒿素对这些NP。我们的初步数据显示， 我们的新型蒿甲醚缀合的NP（A-NP）提供了针对实验性CM（eCM）的完全保护。 A-NP表现出抗寄生虫活性，并且相对于A-NP，A-NP优先靶向受感染的红细胞（iRBC）。 uRBC。我们的对照NPs（C-NPs），其是没有药物的NPs，提供了显著的（p<0.05）保护， eCM而不影响寄生虫血症。这些发现表明，A-NP可能表现出抗寄生虫和抗肿瘤的双重作用。 在一个单一的，易于管理的化合物连续治疗效果。 目前还没有FDA批准的CM的预防性治疗来改善病原性宿主反应 并降低15-30%在充分抗寄生虫治疗后死亡的CM患者的死亡率 化疗此外，这种改善病原性宿主反应的连续疗法还可 减少Pf感染后导致非洲儿童终身残疾的神经损伤， 生存CM。我们使用定义明确、可重复的伯氏疟原虫ANKA感染小鼠作为CM模型 (i.e., eCM）。我们假设我们的新型纳米颗粒通过以下方式防止eCM的发展： 减少导致eCM的致病过程，即，血管源性水肿，氧化应激，炎症， 隔离症和凝血病。在目标1中测试NP作为针对eCM的连续治疗的功效。 目的2中测试了NP作为连续治疗的作用机制。 脑型疟疾是一种由多种致病过程组成的综合征，包括脑水肿、Pf- 感染的红细胞隔离、氧化应激、凝血病和炎症。血管源性水肿是 通过磁共振成像在非洲CM儿童中观察到血管源性水肿， 成年人有CM，但不太明显。我们的初步数据表明，C-NPs显著（p<0.05） 与溶剂相比，在eCM期间通过Evans Blue染料挤出到脑中测量的血管渗漏减少 对照A-NPs比C-NPs更能降低血管渗漏，达到与未感染小鼠相似的水平。 因此，我们的初步数据表明，纳米颗粒通过减少血管生成， 漏水我们还将评估在何种程度上，其他关键的致病机制在eCM的影响，我们的 eCM保护性NP。CM患者和eCM小鼠都表现出氧化应激，寄生虫隔离， 凝血病和炎症作为可能的致病过程，因此确定哪些机制是 我们的eCM保护性A-NP显著减少，突出了未来其他药物的靶向过程 发展 该提案符合R21探索性赠款指南，因为它的重点是评估一种新的 这种药物的机制尚未明确，除了我们的初步数据外，几乎没有实验支持。 后续研究将使用生成的数据深入研究机制，并将国家方案移至 诊所

Neurological dysfunction is an important complication of blood stage Plasmodium falciparum (Pf) infection and the syndrome is called cerebral malaria (CM). We have developed human serum albumin (HSA) nanoparticles (NPs) that are nanoscale aggregates of albumin as a carrier for drug delivery and conjugated anti-bloodstage Plasmodium drugs, including artemether (A) and artemisinin to these NPs. Our preliminary data indicate that our novel artemether-conjugated NPs (A-NPs) provide complete protection against experimental CM (eCM). A-NPs exhibit anti-parasite activity and are preferentially targeted to infected red blood cells (iRBCs) over uRBCs. Our control NPs (C-NPs), which are NPs without drug, provide significant (p<0.05) protection against eCM without affecting parasitemia. These findings suggest that A-NPs may exhibit both anti-parasite- and adjunctive-therapy effects in a single, easy to administer compound. There is currently no FDA-approved adjunctive therapy of CM to ameliorate the pathogenic host response during CM and to decrease mortality in the 15-30% of CM patients who die after adequate anti-parasite chemotherapy. In addition, this adjunctive therapy to ameliorate the pathogenic host response may also decrease the neurological impairment after Pf infection that results in life-long disability for African children who survive CM. We use the well-defined, reproducible P. berghei ANKA infection of mice as our model for CM (i.e., eCM). We hypothesize that our novel nanoparticles protect from development of eCM by decreasing pathogenic processes leading to eCM, i.e., vasogenic edema, oxidant stress, inflammation, sequestration, and coagulopathy. The efficacy of NPs as adjunctive therapy against eCM is tested in Aim 1. Mechanism(s) of action of NPs as adjunctive therapy are tested in Aim 2. Cerebral malaria is a syndrome comprised of multiple pathogenic processes that includes brain edema, Pf- infected red blood cell sequestration, oxidant stress, coagulopathy, and inflammation. Vasogenic edema is observed by magnetic resonance imaging in African children with CM; the vasogenic edema occurs in Indian adults with CM but is less pronounced. Our preliminary data indicate that C-NPs significantly (p<0.05) decrease vascular leak measured by Evans Blue dye extrusion into brain during eCM compared with vehicle controls. A-NPs decreased vascular leak even further than C-NPs to levels similar to those in uninfected mice. Our preliminary data therefore suggest that NPs function as adjunctive therapy in eCM by reducing vascular leak. We will also assess the extent to which other key pathogenic mechanisms in eCM are affected by our eCM-protective NPs. Patients with CM and mice with eCM both exhibit oxidant stress, parasite sequestration, coagulopathy, and inflammation as possible pathogenic processes, so defining which mechanisms are significantly decreased by our eCM-protective A-NPs highlights targetable processes for additional future drug development. This proposal meets R21 exploratory grant guidelines because it is focused on assessing the efficacy of a new drug with undefined mechanisms for which there is little experimental support beyond our preliminary data. Follow-on studies will use the generated data for in-depth studies of mechanisms and to move the NPs to the clinic.