Targeted Nanogel based Therapies for Chronic Recurrent Urinary Tract Infections

项目总结 反复尿路感染(RUTI)是最常见的细菌感染之一，导致 仅在美国就估计有26.8万例。细菌，如致泌尿系统的大肠杆菌(UPEC)，遵循 细胞内细菌群落(生物膜)建立的多步骤致病循环 感染期间的尿路上皮炎。条件致病菌铜绿假单胞菌也形成高度耐药 生物被膜和感染长期留置尿管的患者。目前的预防性抗生素方案无法 进入尿路上皮内的长寿命细胞内细菌库会使抗生素效率低下，而 助长了抵抗。我们提出了一种治疗RUTI的新方法，其中靶向纳米凝胶具有高度的 多种抗生素可经尿路输送至膀胱壁。我们最近发表了研究结果 其中证明了细胞穿透肽CGCKRK当共价结合在 生物相容的丙烯酸纳米凝胶表面，可以有效地结合和穿透裸鼠/损伤的小鼠 在活体膀胱壁中，并成功地在小鼠尿路上皮内输送模拟药物。基于体外实验 在体内收集的初步数据，我们已经详细说明了一个项目计划，在该计划中，纳米凝胶网络 穿透尿路上皮使抗生素的持续输送能够成功治疗尿路感染 精心设计的。我们将通过1)合成具有增强能力的纳米凝胶来扩展我们的初步方法 将治疗相关剂量的抗生素(环丙沙星和庆大霉素)封装并释放到 生理相关的时间尺度和体外测试；2)建立成功治疗Ruti的条件 在体内小鼠感染模型中。中描述的靶向膀胱给药系统的其他潜力 这一提议是同时提供多种疗法的能力，例如单一抗生素，以及 抗生素鸡尾酒或生物膜分散分子。一种膀胱给药系统的研制 这也可用于推进其他膀胱病变的治疗。

PROJECT SUMMARY Recurrent urinary tract infections (rUTI) are among the most common bacterial infections, causing an estimated 268,000 cases in the US alone. Bacteria such as the uropathogenic Escherichia coli (UPEC) follow a multistep, pathogenic cycle in which intracellular bacterial communities (biofilms) are established within the urothelium during infection. The opportunistic pathogen Pseudomonas aeruginosa also forms highly resistant biofilms and infects chronically-catheterized patients. The inability of current prophylactic antibiotic regimens to access the long-lived intracellular bacterial reservoirs within the urothelium renders antibiotics inefficient while contributing to resistance. We propose a novel approach to treat rUTI in which targeted nanogels with high loading of multiple antibiotics can be delivered transurethrally to the bladder wall. We recently published results in which it was demonstrated that the cell penetrating peptide CGCKRK, when covalently conjugated on the surface of a biocompatible acrylic nanogel, can efficiently bind and penetrate the denuded/injured murine bladder wall in-vivo and successfully deliver a drug mimic within the murine urothelium. Based on the in vitro and in vivo preliminary data gathered, we have detailed a project plan in which nanogel networks that penetrate the urothelium to enable the sustained delivery of antibiotics to successfully treat rUTIs will be engineered. We will expand on our preliminary methods by 1) synthesizing nanogels with enhanced capacity to encapsulate and release therapeutically relevant doses of antibiotics (ciprofloxacin and gentamicin) in physiologically relevant timescales and tested in vitro and; 2) establish the conditions to successfully treat rUTI in an in-vivo murine infection model. Additional potential of the targeted bladder delivery systems described in this proposal is the ability to simultaneously deliver multiple therapeutics, such as a single antibiotic, an antibiotic cocktail or a biofilm dispersing molecule. The development of a bladder delivery system described here could also be used to advance treatments of other urinary bladder pathologies.