New Multifunctional Quantum Dot Platforms for Tracking Coupled Proteolytic Activity or Combined Diagnosis and Therapy

纳米粒子代表了化学和光谱学的新前沿，旨在检测与疾病和病原体相关的生物标记物。它们的体积足够小，可以接触到细胞等生物环境，但它们的表面积足够大，可以实现不同的化学和生物功能。这些特性还被独特的依赖于尺寸的光学和电学特性所补充。我们建议使用一种明亮发光的半导体纳米粒子，称为“量子点(QD)”，作为一个平台，利用荧光光谱检测蛋白酶活性。蛋白水解酶是一种参与大量生物信号传递过程的酶；蛋白分解活性的异常与一些心血管和炎症性疾病、许多类型的癌症、骨质疏松症、某些神经疾病以及许多病原体(如艾滋病毒、疟疾)的毒力有关。两个重要的科学挑战是(1)更好地了解蛋白酶的功能，包括它们在信号网络和级联中相互之间的复杂关系，以及(2)提高我们同时检测生物样品和环境中多个蛋白酶活性的能力。我们建议通过三个方面的研究来应对这些挑战。首先，我们将设计基于QD的原型诊断平台，只需连接到笔记本电脑，即可测量生物样本中多种蛋白酶的活性，从而加强床边诊断。其次，我们将构建QD探针，可以用来可视化细胞内一种酶对另一种酶的激活，以帮助阐明生物功能，这对于开发针对蛋白酶的新诊断或治疗至关重要。最后，我们将探索设计新的QD探针，通过将检测与抑制效应相结合来提供同时诊断和治疗的效用。在每一种情况下，量子点的发光特性、大小和表面积的组合将唯一地允许这些预期的创新。这项研究进一步发展了我们关于如何使用纳米技术来应对生物医学挑战的知识，从长远来看，这有望为加拿大人带来更好的医疗保健。

Nanoparticles represent a new frontier for chemistry and spectroscopy aimed at the detection of biomarkers associated with diseases and pathogens. Their size is sufficiently small to access biological environments, such as cells, yet their surface area is sufficiently large to permit diverse chemical and biological functionalization. These properties are further complemented by unique size-dependent optical and electronic properties. We propose to use a type of brightly luminescent semiconductor nanoparticle, called a "quantum dot (QD)," as a platform to detect protease activity using fluorescence spectroscopy. Proteases are enzymes that are involved in a large number of biological signaling processes; aberrations in proteolytic activity are implicated in some cardiovascular and inflammatory diseases, many types of cancer, osteoporosis, certain neurological disorders, and the virulence of many pathogens (e.g. HIV, malaria). Two important scientific challenges are (1) better understanding how proteases function, including their complex relationships with one another in signaling networks and cascades, and (2) improving our ability to simultaneously detect the activity of multiple proteases in biological samples and environments. We propose to address these challenges with research in three areas. First, we will design prototype QD-based diagnostic platforms that can measure the activity of multiple proteases in biological samples with only a connection to a laptop computer, thus potentiating bedside diagnostics. Second, we will construct QD probes that can be used to visualize the activation of one protease by another within cells to help elucidate biological function, which is critical for developing new diagnostics or therapies that target proteases. Finally, we will explore the design of new QD probes that can provide concurrent diagnostic and therapeutic utility by integrating detection with inhibitory effects. In each case, the combined luminescent properties, size, and surface area of QDs will uniquely permit these prospective innovations. This research further develops our knowledge of how to use nanotechnology to address biomedical challenges, which, in the long-term, is expected to lead to better healthcare for Canadians.