Quantifying Kidney Function with Quantum Dot Nanoprobes

描述(申请人提供)：蛋白尿是许多原发和继发性肾小球疾病的标志和替代标志，导致糖尿病和高血压患者发生严重的肾功能障碍。为了加强与这一严重疾病相关的诊断和治疗需求，该项目寻求通过以下方法对体内肾小球通透性进行精确量化：(1)应用新一代半导体纳米晶体(硫化镉/硫化锌量子点)作为高精度尺寸的尺子和非常灵敏的静电纳米传感器；(2)结合最新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组织深层穿透。目前，我们能够对活体动物肾脏内的单个肾小球和管周结构进行成像。我们假设，将这些新的量子点(QD)系统与体内双光子显微镜结合使用，将大大提高我们成像的准确性和灵敏度，因为它的性能优于用于肾脏研究的传统葡聚糖探针，从而更好地了解肾小球疾病的过程，并导致早期临床测试的发展，以量化肾小球的通透性。我们预测这一结果是因为量子点的形状是刚性的和球形的，并且可以得到具有高单分散性、高光稳定性和亮度以及可调节的表面化学性质的量子点。可以通过应用薄薄的生物惰性极性涂层来实现类似尺寸尺子的精度，而中性-极性(丝氨酸封顶)和负电荷(天冬氨酸封顶)多肽涂层量子点将被用于创建类似蛋白质的表面属性。这个跨学科项目的目标是将生物医学应用中使用尖端纳米粒子探头的专业知识(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、能够实现活体肾脏成像的成像/探头系统。这项拟议的研究将应用这一新的成像策略，与NIH路线图中概述的定量成像和纳米医学领域的一个主要主题高度相关，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、提高患者护理质量和寻找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.