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标的耗尽，强调了对新抗感染药物和策略的需求。进一步的抗感染药物开发将由发现感染性疾病的致病分子过程驱动，感染性疾病的致病分子过程通常由上皮表面的宿主-病原体相遇引发。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，其利用称为1型菌毛的粘附纤维来结合和侵入膀胱上皮细胞。急性UTI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驻留，抵抗口服抗生素治疗，并重新出现，导致这些复发。在本申请中，我们提出通过将携带抗菌剂的聚合物纳米颗粒（NPs）与细菌粘附素（一种赋予我们的革兰氏阴性病原体模型上皮结合和侵袭能力的蛋白质）缀合来将抗感染剂递送到上皮细胞中。我们的第一个目标将是完善的化学过程，通过该过程，一个主题蛋白质（特别是结合域的E。大肠杆菌1型菌毛粘附素FimH）可以以有利的取向和分布缀合到一系列聚合物NP的外部。其次，我们将证明这些功能化的纳米颗粒在体外和体内进入膀胱上皮细胞的粘附素依赖性内化，提供独特的可用控制，以证明粘附素-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改性的银卡宾抗菌剂到NP中的负载。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抗微生物的粘附素偶联的纳米颗粒的抗感染活性。杆菌该系统的优点包括能够将高浓度的抗菌剂递送至病原体可能驻留的细胞内区室，避免与全身性抗生素和NP施用相关的毒性，以及蛋白质“包衣”和抗菌剂乘客的结构设计的灵活性。虽然我们将使用哺乳动物泌尿道的细菌感染来模拟我们的系统的效用，但是将选择的药理学试剂递送到选定的上皮细胞群体中将具有跨越感染性疾病、癌症和疫苗抗原递送的更广泛的应用。 公共卫生相关性：复发性尿路感染（UTI）困扰着许多其他健康的女性，并使其他尿路疾病复杂化。我们建议开发纳米级颗粒轴承银基抗菌剂，并涂有细菌蛋白质，赋予粘附到膀胱表面。我们将评估这些纳米颗粒预防和治疗UTI的能力。

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.