低毒近红外发光量子点与蛋白质相互作用的热力学基础

Quantum Dots (QDs) have special fluorescence properties, applications of QDs in bioscience, therapy and diagnosis are attracting more and more attention. Near-infrared (NIR) fluorescent QDs have some special characteristics in biomedicinal imaging, such as its minimized biological autofluorescence background and the increased penetration of excitation and emission light through tissues in the NIR wavelength window. Interaction of the most important bio-substances, proteins, with QDs is inevitable, when QDs are got into human body. In this proposal, low toxicity NIR Ag2S and Ag2Se QDs with different composition, morphologies, sizes, surface charges and surface structures will be selected, and its interaction with some important proteins in human body and some medical ones become very important. Thermodynamic and kinetic parameters will be determined, and influences of QDs size, hydrophobicity, surface structure, and molecular structure of the proteins as well as compositions of the media on the thermodynamic and kinetic properties will be investigated. Some useful rules will be summarized and explained based on electronic microscope observation and analyses of spectra of fluorescence, CD, XPS, FT-IR etc. The order of affinities of proteins to each kind of nanoparticles in a certain structure will be found out and expressed by thermodynamic parameter such as the interaction equilibrium constants, and the order of competing interaction rates will also be found and expressed by using the kinetic parameters. Comprehensive thermodynamic and kinetic research on each kind of NIR QDs will be performed for the interaction processes of various proteins. The biological effect mechanism of different NIR QDs, and the relationship between NIR QDs structure and thermodynamic parameters, will be disclosed. The research will provide a lot of important information on synthesis, safe application and biosafty evaluation of NIR QDs.

量子点是一种新型的荧光标记纳米材料，具有优异的光学性能及丰富的表面化学性质，适用于生物医学标记和成像。近红外量子点生物成像时背景干扰小、穿透深度大，具有更大优势。量子点进入机体，蛋白质与其表面发生相互作用。本项目拟以低毒近红外发光Ag2S和Ag2Se量子点为研究对象，采用微量热、荧光、电化学、SPR等方法，研究不同结构、不同表面性质的量子点与血浆中重要蛋白质的相互作用。获取相关作用的热力学和动力学参数，并探讨量子点组成、结构、表面亲/疏水性和电荷等因素及蛋白质分子结构对热力学和动力学性质影响，及其规律性。结合电镜、CD、XPS、FT-IR等，从微观结构诠释所得规律。利用热力学参数表达其蛋白冠的稳定性，获取其对不同蛋白质的亲和性强弱顺序；通过动力学参数，揭示动态竞争作用规律。对多种蛋白质与量子点相互作用过程，进行热力学和动力学综合研究，将为量子点在生物医学中高效、安全应用，提供科学依据。

量子点是一种新型的荧光标记纳米材料，具有优异的光学性能及丰富的表面化学性质，适用于生物医学标记和成像。低毒和近红外发光，是量子点生物标记的发展趋势，且具有更大优势。量子点进入机体，蛋白质与其表面发生相互作用。本项目以低毒和近红外发光量子点为研究对象，设计并制备了不同结构、不同表面性质的量子点，研究了它们的基本性质及其与细胞和线粒体相互作用特征。采用微量热、荧光、电化学、SPR等方法，研究了它们与血浆中重要蛋白质的相互作用。获取相关作用的热力学和动力学参数，并探讨量子点组成、结构、表面亲/疏水性和电荷等因素及蛋白质分子结构对热力学和动力学性质影响，及其规律性。结合电镜、CD、XPS、FT-IR等，从微观结构诠释所得规律。利用热力学参数表达其蛋白冠的稳定性，获取其对不同蛋白质的亲和性强弱顺序；通过动力学参数，揭示动态竞争作用规律。对多种蛋白质与量子点相互作用过程，进行热力学和动力学综合研究，为量子点在生物医学中高效、安全应用，提供科学依据。.项目21473125的相关研究工作共发表了SCI论文27篇(其中一区9篇、二区14篇)、综述论文2篇，较好的完成了项目研究任务。