Bioaffinity Nanoparticle Probes for Bioimaging (RMI)

描述（由申请人提供）：这一P20申请旨在通过整合埃默里大学（亚特兰大，乔治亚州）的生物医学专业知识、佐治亚理工学院（亚特兰大，乔治亚州）的工程实力、斯克里普斯研究所（La Jolla， CA）强大的有机化学和哈佛大学（剑桥，MA）的单分子生物物理创新，建立一个先进的成像探针项目。其广泛和长期的目标是开发一类具有双细胞传递和靶向功能的新型生物共轭发光纳米颗粒，用于活细胞中单分子过程的实时和多色荧光成像。所提出的纳米颗粒合成、细胞传递和有机化学的研究广泛适用于许多类型的纳米级颗粒，如胶体金属纳米颗粒、染料掺杂二氧化硅和聚合物纳米颗粒。但是，由于核壳半导体量子点（QDs）具有新的光学特性，如提高亮度，抗光漂白和同时多色激发，因此将被特别关注。量子点也处于中间或“介观”尺寸范围（直径1-10纳米），它提供了足够的表面积来连接多个递送和靶向配体，同时避免了主要的动力学或位阻问题。这些特性超出了有机染料和荧光蛋白的固有能力，并且最有希望将分子和细胞成像的灵敏度提高10到100倍。在开发探针的同时，我们将探索创新的单分子成像和信号处理方法，以区分活细胞内的结合靶和未结合靶。与细胞生物学家合作，QD探针和单分子成像将用于研究涉及程序性细胞死亡的复杂分子事件，特别是p53蛋白、核因子κ B和雄激素受体的亚细胞定位，以及微管和分子马达在将基因调控蛋白从细胞质转运到细胞核中的作用。生物亲和性QD探针的发展将给单分子生物物理学和分子/细胞生物学带来重大变化。其潜在的实际成果包括具有改进光学特性的新一代半导体量子点探针，用于细胞传递和诊断和治疗药物靶向的小分子文库和生物分子工程方法，以及广泛科学界使用的单分子成像硬件和软件。

DESCRIPTION (provided by applicant): This P20 application aims to establish an advanced imaging probes program by integrating the biomedical expertise of Emory University (Atlanta, GA), the engineering strength of Georgia Tech (Atlanta, GA), the powerful organic chemistry of Scripps Research Institute (La Jolla, CA), and the single-molecule biophysical innovations of Harvard University (Cambridge, MA). Its broad and long-term goal is to develop a new class of bioconjugated luminescent nanoparticles with dual cellular delivery and targeting functions for real-time and multicolor fluorescence imaging of single-molecule processes in living cells. The proposed research on nanoparticle synthesis, cellular delivery, and organic chemistry is broadly applicable to many types of nanometer-sized particles such as colloidal metal nanoparticles, dye-doped silica, and polymeric nanobeads. But a particular focus will be placed on core-shell semiconductor quantum dots (QDs) because of their novel optical properties such as improved brightness, resistance against photobleaching, and simultaneous multicolor excitation. Quantum dots are also in an intermediate or "mesoscopic" size range (1-10 nm diameter) that provides enough surface area for linking to multiple delivery and targeting ligands while avoiding major kinetic or steric hindrance problems. These properties are beyond the intrinsic capabilities of organic dyes and fluorescent proteins, and are most promising for improving the sensitivity of molecular and cellular imaging by a factor of 10 to 100. In parallel with probe development, we will explore innovative single-molecule imaging and signal processing methods in order to discriminate bound targets from unbound probes inside living cells. In collaboration with cell biologists, the QD probes and single-molecule imaging will be used to study complex molecular events involved in programmed cell death, especially the subcellular localization of p53 protein, nuclear factor kappa B, and androgen receptor, as well as the involvement of microtubules and molecular motors in transporting gene-regulatory proteins from the cytoplasm to the cell nucleus. The proposed development of bioaffinity QD probes should bring major changes to single-molecule biophysics and molecular/cellular biology. Its potential practical outcomes include a new generation of semiconductor QD probes with improved optical properties, small-molecule libraries and biomolecular engineering methods for cellular delivery and targeting of diagnostic and therapeutic agents, and single-molecule imaging hardware and software for use by the broad scientific community.