Monovalent Nanocrystals for Biomedical Imaging

描述（由申请人提供）：提出了一种方法，用于开发无毒量子点合成的有效和通用程序，以及用于将这些量子点偶联或“标记”到蛋白质上，以增强和改进生物医学成像技术。人们普遍认为，量子点在蛋白质标记和其他成像技术中的应用比有机染料或金纳米晶体具有许多优势。通过成像技术检测疾病的方法需要量子点与生物分子偶联的新方法。拟议的项目涉及在有机合成（准备用于钝化和稳定纳米晶体的定制树突）、纳米晶体合成（设计和合成具有可调电子和光谱特性的无毒纳米晶体）、物理生物化学（证明将设计的纳米晶体附着在参与细胞信号传导的代表性蛋白质上的可行性）、以及单分子光谱学（以证明所设计的系统在蛋白质折叠研究中的帮助能力）。该团队将开发技术来表征纳米晶体生物偶联物在体外和随后的体内以前未实现的结构和/或生物特性。该项目的完成有望证明生物纳米技术作为诊断和治疗的新途径的优势。这个探索性项目有三个具体目标：1。合成、表征和优化合适的功能化树突，用于连接无毒Mn掺杂ZnSe （Mn:ZnSe d-dots）和InAs/InP/ZnS核/壳/壳近红外量子点。2. 探索固相合成策略制备Mn:ZnSe d-dots共价连接到聚合物树脂。用甲氧基乙基胺帽状树状大分子衍生出水溶性量子点。3. 通过四种连接剂功能化单价d-dots用于蛋白质偶联，这将在各种蛋白质应用中提供最大的潜力：硝基三乙酸（NTA）， n -羟基琥珀酰亚胺（NHS），马来酰亚胺和酰基肼。将d-dots与代表性蛋白质结合，纯化，并进行化学和光谱表征。

DESCRIPTION (provided by applicant): Methodology is proposed to develop efficient and general procedures for the synthesis of nontoxic quantum dots, and for conjugating, or 'tagging' these dots to proteins, for the purpose of enhancing and improving biomedical imaging techniques. It is generally agreed that quantum dots (QDs) offer many advantages over organic dyes or gold nanocrystals in applications of protein tagging and other imaging technologies. Approaches to disease detection via imaging techniques require novel methods of QD conjugation to biomolecules. The proposed project involves a collaboration between Principal Investigators with expertise in organic synthesis (to prepare tailored dendrons for use in passivating and stabilizing nanocrystals), nanocrystal synthesis (to design and synthesize nontoxic nanocrystals with tunable electronic and spectroscopic properties), physical biochemistry (to demonstrate the feasibility of attachment of the designed nanocrystals to a representative protein that is involved in cell signaling), and single molecule spectroscopy (to demonstrate the ability of the designed systems to aid in the study of protein folding). The team will develop techniques to characterize previously unrealized structural and/or biological properties of nanocrystal bioconjugates in-vitro, and subsequently in-vivo. Accomplishment of the aims of this project is expected to demonstrate the advantages of bionanotechnology as a new avenue of diagnostic and therapeutic treatment. This exploratory project has 3 specific aims: 1. Synthesize, characterize, and optimize appropriately functionalized dendrons for ligation to nontoxic Mn-doped ZnSe (Mn:ZnSe d-dots) and InAs/InP/ZnS core/shell/shell near infrared (NIR) QDs. 2. Explore solid-phase synthesis strategies to prepare Mn:ZnSe d-dots that are covalently attached to polymer resins. Derivatize the quantum dots for water solubility using methoxyethylamine-capped dendrimers. 3. Functionalize the monovalent d-dots for protein conjugation via four linkers that will provide maximum potential in a wide variety of protein applications: nitrilotriacetic acid (NTA), N-hydroxysuccinimide (NHS), maleimide, and acyl hydrazide. Conjugate the d-dots with representative proteins, purify, and characterize chemically and spectroscopically. PUBLIC HEALTH RELEVANCE: Organic dyes have been used for years in biomedical imaging applications, but they suffer from a number of limitations, many of which can be overcome by using nanometer-sized crystals (nanocrystals, also known as quantum dots). Past efforts in this area have several drawbacks, including toxicity from the heavy metal components of commercially available nanocrystalline materials, methods for the synthesis of nontoxic quantum dots, and inefficient methods for coupling quantum dots to biomolecules such as proteins. The University of Arkansas team directing this project aims to overcome these limitations, and is uniquely qualified to do so, since it comprises Principle Investigators with expertise in every aspect of the synthesis and evaluation of protein-coupled nontoxic quantum dots.