Quantifying Kidney Function with Quantum Dot Nanoprobes

描述（由申请人提供）：蛋白尿是糖尿病和高血压患者发生的许多原发性和继发性肾小球疾病的标志和替代标志物，这些疾病导致严重的肾功能障碍。为了提高与这种严重疾病相关的诊断和治疗需求，本项目试图通过以下方式以无与伦比的精度量化体内肾小球渗透性：(1)应用新一代半导体纳米晶体（CdSe/ZnS量子点）作为高精度的尺寸尺和非常灵敏的静电纳米传感器，结合(2)最近开发的定量双光子激发显微成像技术，使用超快近红外激光进行深层组织穿透。目前，我们能够在活体动物肾脏中成像单个肾小球和小管周围结构。我们假设，使用这些新型量子点（QD）系统与体内双光子显微镜相结合，将大大提高成像的准确性和灵敏度，优于肾脏研究中使用的传统葡聚糖探针，从而更好地了解肾小球疾病过程，并导致早期临床试验的发展，以量化肾小球渗透率。我们预测这一结果是因为量子点是刚性和球形的，并且可以产生高单分散性，高光稳定性和亮度以及可调节的表面化学性质。通过应用薄的生物惰性极性涂层可以实现类似“尺寸尺”的精度，而中性极性（Ser-capped）和负电荷（Asp-capped）肽包被的量子点将用于创建类似蛋白质的表面特性。这个跨学科项目的目标是将尖端纳米颗粒探针用于生物医学应用的专业知识（Naumann, Long）和最先进的光学成像技术（Yu, Molitoris）结合起来，开发一种显著改进的、能够用于活体肾脏成像的成像/探针系统。拟议的研究将应用这种新的成像策略，与NIH定量成像和纳米医学领域路线图中概述的主要主题高度相关，以提供对肾小球滤过屏障功能的基本了解，并深入了解肾小球损伤与蛋白尿症状发作之间的相关性。我们的研究结果将为早期诊断、提高病人护理质量和找到未来的治疗方法提供有价值的信息。

DESCRIPTION (provided by applicant): Proteinuria is the hallmark and surrogate marker of many primary and secondary glomerular diseases resulting in serious kidney malfunctions that occur in patients with diabetes and hypertension. To enhance the diagnostic and therapeutic needs related to this serious disease, this project seeks to quantify glomerular permeability in vivo with unmatched precision by: (1) applying a new generation of semiconductor nanocrystals (CdSe/ZnS quantum dots) as highly accurate size rulers and very sensitive electrostatic nanosensors combined with (2) a recently developed quantitative two-photon excitation microscopic imaging technique that uses ultrafast near-infrared laser for deep tissue penetration. Currently, we are able to image individual glomeruli and peritubular structures inside a live animal kidney. We hypothesize that the use of these novel quantum dot (QD) systems in conjunction with in vivo two-photon microscopy will increase vastly the accuracy and sensitivity of our imaging by outperforming traditional dextran probes used in kidney studies, resulting in a better understanding of glomerular disease processes and leading to the development of early clinical tests to quantify glomerular permeability. We predict this outcome because quantum dots are rigid and spherical in shape, and can be produced with high monodispersity, high photostability and brightness as well as adjustable surface chemical properties. A "size ruler"-like accuracy can be achieved by applying thin bioinert polar coatings, whereas neutral-polar (Ser-capped) and negatively charged (Asp-capped) peptide-coated QDs will be used to create protein-like surface properties. The goal of this interdisciplinary project is to combine expertise concerning the use of cutting-edge nanoparticle probes for biomedical applications (Naumann, Long) and the state-of-the-art optical imaging (Yu, Molitoris) to develop a significantly improved and enabling imaging/probe system for intravital kidney imaging. The proposed study will apply this new imaging strategy, highly relevant to a major theme outlined in the NIH Roadmap in areas of Quantitative Imaging and Nanomedicine, to provide a basic understanding of the functions of glomerular filtration barrier and insight into the correlation between glomerular damage and the onset of proteinuric symptoms. The results of our study will offer valuable information important for early diagnosis, improving the quality of patient care, and finding a future cure.