Synthetic Scavenger Medical Countermeasures for Fentanyl

项目总结/摘要 阿片类药物滥用在美国已成为一种日益严重的流行病，每年造成数万人过量死亡。 特别是因为芬太尼相关的阿片类药物。芬太尼是一种合成阿片类药物， μ-阿片受体在不同的网站，估计是100倍以上的吗啡效力。这导致 将有效的合成阿片类药物分类为药物基制剂（PBAs）， 潜在的进攻性化学武器，表明迫切需要有效的医疗对策（MCM）。 纳洛酮是一种非选择性竞争性阿片受体拮抗剂，用于逆转 阿片类药物过量或中毒。它非常有效，但也有一些缺点。例如，它具有低 对芬太尼等强效阿片类药物有效，可能需要多次给药以避免再麻醉，但随后可能 诱发阿片类药物戒断综合征对于暴露后的两种情况，Biosscavengers都是一种有吸引力的MCM策略。 治疗和预防毒剂如有机磷酸盐神经毒剂。最近，单克隆 在小鼠中显示抗体（mAbs）是芬太尼和卡芬太尼的生物清除剂， 浓度的然而，由于需要化学计量的生物清除剂来中和芬太尼分子， 由于mAb较大（~150 kDa），因此保护免受或治疗阿片样物质所需的mAb剂量 毒性大且难以施用。因此，迫切需要可用于以下用途的新MCM： 与受体拮抗剂如纳洛酮联合使用，以克服目前治疗的局限性。 这项探索性研究计划旨在开发芬太尼的合成清除剂，用于阿片类药物过量， 利用SRI专有的光纤阵列筛选技术（FAST）和蛋白质样 合成分子（Technein）。我们开发了这个平台，使设计，合成，筛选和 大型组合“一珠一化合物”Technein文库的测序。FAST支持筛选 针对复杂生物基质中的多个靶标，以产生具有特定生物活性的先导化合物， 功能性和高选择性。这种方法已被验证为药物发现工具的抑制剂， 蛋白质-蛋白质相互作用和小分子结合剂。在初步研究中，当一小部分 针对芬太尼筛选文库，鉴定了几个Technein命中物并确认结合。他们的 相对较小的尺寸（4-6 kDa）、高稳定性、缺乏免疫原性和良好的终末半衰期（约22小时）， 使Technein成为阿片类清除剂的理想候选者。 在这里，我们的目标是开发芬太尼的合成清除剂Technein，并测试和优化其阻断芬太尼的能力。 芬太尼活性的功能细胞测定（目的1），并提供基本的PK和临床前疗效数据， 顶级抗芬太尼铅（Aim 2）。这些研究将为开发有效的MCM开辟新的途径 针对芬太尼和相关的合成阿片类药物，以及为应对其他类型的有毒物质铺平道路 剂.此外，该项目还可以进一步展示创新新药发现平台的实用性。

PROJECT SUMMARY/ABSTRACT Opioid abuse has become a growing epidemic in the US, causing tens of thousands of overdose deaths every year especially because of fentanyl-related opioids. Fentanyl is a synthetic opioid that acts as an agonist on the μ-opioid receptors at various sites and is estimated to be 100 times more potent than morphine. This has led to the classification of potent synthetic opioids as Pharmaceutical Based Agents (PBAs) that could be used as a potential offensive chemical weapon, indicating the critical need for effective medical countermeasures (MCMs). Naloxone is a non-selective competitive opioid receptor antagonist that is given to reverse the symptoms of opioid overdose or toxicity. It is highly effective, but also has several disadvantages. For example, it has low efficacy against potent opioids like fentanyl and can require multiple doses to avoid renarcotization, but may then precipitate opioid-withdrawal syndrome. Bioscavengers are an attractive MCM strategy for both post-exposure therapy and prophylaxis against toxic agents such as organophosphate nerve agents. Recently, monoclonal antibodies (mAbs) were shown in mice to be fentanyl and carfentanil bioscavengers, and to reduce blood opioid concentrations. However, since a stoichiometric bioscavenger is needed to neutralize the fentanyl molecules, and since mAbs are large (~150 kDa), the dose of the mAbs required for protection from or treatment of opioid toxicity is large and difficult to administer. Therefore, an urgent need exists for new MCMs that can be used in conjunction with receptor antagonists like naloxone to overcome the limitations of current treatments. This exploratory research program seeks to develop synthetic scavengers for fentanyl for opioid overdose and toxicity reversal utilizing SRI’s proprietary Fiber-optic Array Screening Technology (FAST) and protein-like synthetic molecules (Techneins). We developed this platform to enable the design, synthesis, screening and sequencing of large combinatorial “one-bead one-compound” Technein libraries. FAST enables screening against multiple targets in complex biological matrices to yield lead compounds with specific biological functionality and high selectivity. This approach has been validated as a drug discovery tool for inhibitors of protein-protein interactions and for small molecule binders. In preliminary studies, when a small portion of a library was screened against fentanyl, several Technein hits were identified and confirmed to bind. Their relatively small size (4-6 kDa), high stability, lack of immunogenicity and a good terminal half-life (~22 hours), make Techneins ideal candidates as opioid scavengers. Here we aim to develop synthetic scavenger Techneins for fentanyl and test and optimize their ability to block fentanyl activity in functional cellular assays (Aim 1) and provide basic PK and pre-clinical efficacy data for the top anti-fentanyl lead (Aim 2). These studies will enable new avenues for the development of efficacious MCMs against fentanyl and related synthetic opioids, as well as paving the way for coping with other types of toxic agents. Moreover, the project may further demonstrate utility of an innovative new drug discovery platform.