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

纳米颗粒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志物。它们的尺寸足够小，可以进入生物环境，如细胞，但它们的表面积足够大，可以实现多种化学和生物功能。这些特性进一步补充了独特的尺寸相关的光学和电子特性。我们建议使用一种称为“量子点（QD）”的发光半导体纳米颗粒作为荧光光谱检测蛋白酶活性的平台。蛋白酶是参与大量生物信号传导过程的酶；蛋白质水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、某些神经系统疾病和许多病原体（如艾滋病毒、疟疾）的毒性有关。两个重要的科学挑战是：(1)更好地理解蛋白酶的功能，包括它们在信号网络和级联中的复杂关系；(2)提高我们在生物样品和环境中同时检测多种蛋白酶活性的能力。我们建议通过三个领域的研究来解决这些挑战。首先，我们将设计基于量子点的原型诊断平台，该平台可以仅通过与笔记本电脑的连接来测量生物样品中多种蛋白酶的活性，从而增强床边诊断。其次，我们将构建QD探针，可用于可视化细胞内一种蛋白酶被另一种蛋白酶激活的过程，以帮助阐明生物学功能，这对于开发针对蛋白酶的新诊断或治疗方法至关重要。最后，我们将探索设计新的QD探针，通过将检测与抑制作用结合起来，提供并发诊断和治疗效用。在每种情况下，量子点的综合发光特性、尺寸和表面积将独特地允许这些有前景的创新。这项研究进一步发展了我们如何利用纳米技术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.