ADHESIN-BASED NANOTHERAPEUTICS IN URINARY TRACT INFECTION

描述（由申请人提供）：最近细菌对现有抗生素的耐药性加速，以及目前已知的微生物细胞生物学和生物化学靶点的枯竭，强调了对新的抗感染药物和策略的需求。进一步的抗感染开发将被发现传染病的致病分子过程所驱动，这些过程通常是由宿主-病原体在上皮表面相遇发起的。尿路感染（uti）是世界范围内发病率和医疗费用的主要来源，主要由尿路致病性大肠杆菌引起，它利用一种称为1型菌毛的粘附纤维结合并侵入膀胱上皮细胞。急性尿路感染后复发是常见的，最近的数据表明，细菌在膀胱组织内建立慢性居住地，抵抗口服抗生素治疗，并重新出现导致这些复发。在这个应用中，我们建议通过携带抗菌剂的聚合物纳米颗粒（NPs）与细菌粘附素（一种赋予上皮结合和侵袭我们的模型革兰氏阴性病原体能力的蛋白质）的结合将抗感染药物输送到上皮细胞中。我们的第一个目标将是改进一个化学过程，通过这个化学过程，一个主体蛋白（特别是大肠杆菌1型菌毛粘附素FimH的结合域）可以以有利的方向和分布在一系列聚合物NPs的外部。其次，我们将在体外和体内证明这些功能化NPs在膀胱上皮细胞中的粘附依赖内化，提供独特的可用对照来证明粘附素受体相互作用的特异性。第三，我们将优化银阳离子和结构可修饰的银碳纳米管抗菌剂的负载。最后，我们建议在体外和由尿路致病性大肠杆菌引起的急性和慢性膀胱炎的小鼠模型中证明这些携带抗菌素的粘附素偶联NPs的抗感染活性。该系统的优点包括能够将高浓度抗菌剂输送到病原体可能存在的细胞内腔室，避免与全身抗生素和NP给药相关的毒性，以及蛋白质“外壳”和抗菌乘客的结构设计灵活性。虽然我们将利用哺乳动物尿路细菌感染来模拟我们的系统的效用，但将选择的药物输送到选定的上皮细胞群中将有更广泛的应用，包括传染病、癌症和疫苗抗原的输送。

DESCRIPTION (provided by applicant): The need for new anti-infective agents and strategies is underscored by recent acceleration in bacterial resistance to existing antibiotics and the exhaustion of currently known targets of microbial cell biology and biochemistry. Further anti-infectives development will be driven by discovery of the pathogenic molecular processes of infectious diseases, which are often initiated by host-pathogen encounters at epithelial surfaces. Urinary tract infections (UTIs), a major source of morbidity and medical costs worldwide, are caused primarily by uropathogenic Escherichia coli, which employ an adhesive fiber termed the type 1 pilus to bind and invade bladder epithelial cells. Recurrences are common after acute UTI, and recent data suggest that bacteria establish chronic residence within bladder tissue, resist oral antibiotic therapy, and re-emerge to cause these recurrences. In this application, we propose to deliver anti-infective agents into epithelial cells via the conjugation of antimicrobial-bearing polymer nanoparticles (NPs) with a bacterial adhesin, a protein that confers epithelial binding and invasion capacity upon our model Gram-negative pathogen. Our first objective will be to refine the chemical processes by which a subject protein (specifically the binding domain of the E. coli type 1 pilus adhesin FimH) can be conjugated with favorable orientation and distribution to the exterior of a series of polymer NPs. Second, we will demonstrate the adhesin-dependent internalization of these functionalized NPs into bladder epithelial cells in vitro and in vivo, providing uniquely available controls to prove the specificity of the adhesin-receptor interaction. Third, we will optimize the loading of silver cation and structurally modifiable silver carbene antimicrobials into the NPs. Finally, we propose to demonstrate the anti-infective activity of these antimicrobial-bearing, adhesin-coupled NPs, both in vitro and in murine models of acute and chronic cystitis caused by uropathogenic E. coli. Advantages of this system include the capability to deliver antimicrobials in high concentration to the intracellular compartment where pathogens may reside, avoidance of toxicities associated with systemic antibiotic and NP administration, and flexibility in the structural design of both the protein "coat" and the antimicrobial passenger. Though we will model the utility of our system using bacterial infection of the mammalian urinary tract, the delivery of pharmacologic agents of choice into selected epithelial cell populations will have broader applications spanning infectious diseases, cancer, and vaccine antigen delivery. PUBLIC HEALTH RELEVANCE: Recurrent urinary tract infection (UTI) plagues many otherwise healthy women and complicates other urinary tract conditions. We propose to develop nanoscopic particles bearing silver-based antibacterial agents and coated with a bacterial protein to confer adhesion to the bladder surface. We will evaluate the ability of these nanoparticles to prevent and treat UTI.