Hybrid nanomaterials for dynamic, intracellular radioisotope detection

描述（由申请人提供）：以增加的灵敏度和时间分辨率分析细胞信号转导通路的能力在理解人类疾病和病症中涉及的潜在分子通路中起着关键作用。其中最具挑战性的分析物是那些以非常低的浓度存在，具有高的时间变异性和小分子缺乏适合光学和/或电化学检测的部分。放射性同位素标记在生物系统的研究中起着关键作用， 和临床环境，特别是对于来自碳水化合物的小分子信号。与荧光标记物等相比，放射性同位素促进了对分析物具有最小扰动的高灵敏度检测。由于生物分子中这些原子的普遍性，包括32 P、35 S、14 C和3 H的β粒子发射体通常用作生物示踪剂。最普遍的放射性同位素标记是3 H，因为H在分子系统中无处不在。3 H具有许多固有的优点，包括标记和未标记化合物之间的低质量差异，合理的储存半衰期和低能量和短穿透深度，使3 H成为最安全的b-发射同位素，通常用于生物分析。不幸的是，与其他放射性同位素相比，低能量和短穿透深度也使3 H的检测复杂化，从而使分析单个细胞或小细胞群中的动态信号传导过程的能力最小化。我们建议开发和表征一种新的核壳纳米材料，称为nanoSPA，功能化与荧光染料的低能量放射性同位素在细胞内环境中的灵敏检测。这种纳米材料是通过将薄二氧化硅壳沉积到掺杂有放射性同位素响应性澄清剂的聚合物核上来制备的。聚合物基质促进能量吸收和从放射性同位素转移到澄清剂染料，而二氧化硅壳的添加增加了在水性样品中的溶解度，并提供了容易改性的表面。与现有技术相比，nanoSPA具有许多优点，包括：a）与水性样品的相容性增强; B）用于改进SPA的高表面积与体积（SA/V）比; c）用于附着生物分子和其它化学物质的容易改性的表面;以及d）用于细胞内放射性同位素成像的适用性。本文提出的nanoSPA平台将在与人类健康相关的广泛应用中提供关键的使能技术。虽然我们将把我们最初的概念验证工作集中在与葡萄糖调节胰岛素分泌相关的测定上，但这项技术的应用范围非常广泛。

DESCRIPTION (provided by applicant): The capability to analyze cellular signal transduction pathways with increasing sensitivity and temporal resolution plays a key role in understanding the underlying molecular pathways involved in human diseases and disorders. Among the most challenging analytes are those present at very low concentrations with high temporal variability and small molecules lacking moieties amenable for optical and/or electrochemical detection. Radioisotopic labels play key roles in the investigation of biological systems in both the research and clinical environments, particularly for small molecule signals derived from carbohydrates. Radioisotopes facilitate highly sensitive detection with minimal perturbation of the analyte, compared to fluorescent labels, etc. Beta-particle emitters, including 32P, 35S, 14C and 3H are commonly used as biological tracers due to the prevalence of these atoms in biological molecules. The most universal radioisotopic label is 3H, due to the ubiquitous presence of H in molecular systems. 3H possesses a number of inherent advantages, including low mass differences between labeled and unlabeled compounds, a reasonable half-life for storage and low energy and short penetration depth that make 3H the safest b-emitting isotope commonly used for biological analysis. Unfortunately, the low energy and short penetration depth also complicate detection of 3H compared to other radioisotopes, minimizing the ability to analyze dynamic signaling processes in single cells or small groups of cells. We propose to develop and characterize a novel core-shell nanomaterial, termed nanoSPA, functionalized with scintillating dyes for sensitive detection of low energy radioisotopes in intracellular environments. This nanomaterial is prepared by depositing a thin silica shell onto a polymer core that is doped with radioisotope- responsive scintillants. The polymer matrix facilitates energy absorption and transfer from the radioisotope to the scintillant dye, whereas addition of the silica shell increass solubility in aqueous samples, and provides an easily modified surface. nanoSPA presents a number of advantages compared to existing technologies, including: a) enhanced compatibility with aqueous samples; b) a high-surface area to volume (SA/V) ratio for improved SPA; c) an easily modified surface for attachment of biomolecules and other chemical species; and d) applicability for intracellular radioisotope imaging. The nanoSPA platform that is proposed herein will provide a key enabling technology in a wide range of applications relevant to human health. Though we will focus our initial, proof-of-concept efforts on assays relevant to glucose-regulated insulin secretion, the range of applications for this technology is extremely broad.