Synthetic Antimicrobial Peptoids for Treatment of Chronic Suppurative Otitis Media

项目总结/摘要 该项目的目标是开发一种新的，有效的治疗慢性化脓性中耳炎（CSOM）， 目前无法治愈的疾病，包括严重的慢性中耳感染。CSOM是最常见的原因 发展中国家儿童的持续性听力损失，影响着全球3.3亿人。是 其特征在于慢性感染、分泌性中耳炎，并且目前没有有效的药物治疗。 细菌铜绿假单胞菌（PA）是CSOM的主要原因，并通过细菌在中耳内定植。 鼓膜穿孔，在那里形成生物膜群落。当前的主 CSOM的治疗方式，氟喹诺酮（通常为氧氟沙星）滴耳液，在完全缓解中无效。 消除CSOM感染，显然是由于无法针对代谢不活跃的亚群 生物膜内的细菌被称为“持久细胞”。这些持续存在的细胞重新填充生物膜生态位后， 氟喹诺酮类药物治疗停止，导致CSOM复发。这个跨学科的项目利用了 结合了圣玛利亚实验室的专业知识，该实验室已经创建了一个具有PA生物膜的CSOM小鼠模型， 最近在中耳翻译方面取得了成功，巴伦实验室开发了抗菌剂。 我们的创新方法包括设计、合成、优化和体内测试独特的生物稳定的 天然抗菌肽（AMP）的类似物。AMP是对抗传染性疾病的天然防御机制， 一些药物对生物膜有效;但它们的生物利用度差（即，体内快速蛋白水解 降解）限制了它们的临床应用。我们将利用AMP模拟物，其是序列和长度特异性的， 天然多肽的寡-N-取代甘氨酸模拟物。在拟肽上，拟肽基于多肽 主链;但具有附加到主链氮的侧链。由于这种结构差异， 对蛋白水解完全稳定。此外，它们可以以合理的成本以高产率制备， 自动化肽合成仪。合成抗菌肽（SAMP）是一种强效药物， 消除生物膜中的存留物。我们的初步数据显示，SAMP在以下情况下比氧氟沙星更有效： 杀死非增殖性持留细胞和根除成熟生物膜。 我们的目标集中在优化我们的领先SAMP候选药物，并确认在CSOM小鼠中的疗效。 模型目的：（1）体外筛选经修饰的TM 5类似物，以提高对临床分离株的效力 持续存在的细胞和成熟的生物膜和（2）显示出概念的证据，即领先的SAMP可以有效地在 CSOM小鼠模型，同时也是无耳毒性的。在完成我们最终的体内疗效后，我们计划继续 通过临床前翻译。在第二阶段的支持下，我们的目标将是显示非全身毒性，安全性， 分布、药代动力学、制剂、稳定性和剂量递增以组装IND包装。

PROJECT SUMMARY / ABSTRACT The goal of this project is to develop a new, effective treatment for chronic suppurative otitis media (CSOM), a currently uncurable condition involving severe, chronic middle ear infection. CSOM is the most common cause of persistent hearing loss for children in the developing world, and affects 330 million people worldwide. It is characterized by a chronically infected, discharging middle ear, and currently has no effective medical therapy. The bacterium Pseudomonas aeruginosa (PA) is a leading cause of CSOM, and colonizes the middle ear via a perforated tympanic membrane, where it becomes established into a biofilm community. The current primary treatment modality for CSOM, fluoroquinolone (usually ofloxacin) eardrops, is ineffective in completely eliminating CSOM infection, apparently due to an inability to target the subpopulation of metabolically inactive bacteria within the biofilm known as ‘persister cells’. These persister cells repopulate the biofilm niche after the fluoroquinolone therapy is discontinued, causing CSOM to relapse. This interdisciplinary project leverages the combined expertise of the Santa Maria lab, which has created a mouse model for CSOM with PA biofilms and has recent middle ear translational success, and the Barron lab, which develops antimicrobials. Our innovative approach involves the design, synthesis, optimization and in vivo testing of uniquely biostable analoguesof natural antimicrobial peptides (AMPs). AMPs are natural defense mechanisms to combat infectious agents in vivo, and some are effective against biofilms; yet their poor bioavailability (i.e. rapid in vivo proteolytic degradation) limits their clinical use. We will utilize AMP mimics based which are sequence- and length-specific oligo-N-substituted glycine mimics of natural polypeptides. on peptoids, Peptoids are based on a polypeptide backbone; yet have side-chains appended to backbone nitrogens. Because of this structural difference, peptoids are completely stable to proteolysis. Furthermore, they can be made in high yields at reasonable cost, using an automated peptide synthesizer. Synthetic Antimicrobial Peptoids (SAMPs) are potent drugs that can completely eliminate persisters in biofilms. Our preliminary data show that SAMPs are more effective than ofloxacin at killing planktonic persister cells and eradicating mature biofilms. Our aims are focused on optimizing our lead SAMP candidate and confirming efficacy in our CSOM mouse model. The Aims are: (1) in vitro screening of TM5 analogs modified to improve efficacy against clinical isolate persister cells and mature biofilms and (2) showing proof of concept that the lead SAMP can be effective in a CSOM mouse model while also being non-ototoxic. After finishing our final in vivo efficacy, we plan to proceed through preclinical translation. With Phase II support, our goals will be to show non-systemic toxicity, safety, distribution, pharmacokinetics, formulation, stability, and dose escalation to assemble an IND package.