應用奈米金粒子探討微觀尺度下生物分子與奈米材料

Abstract

奈米粒子引起的生物毒性有什麼特性？奈米粒子和生物分子之間如何交互作用？如何應用這些現象？ 奈米科技蔚為風潮，大量被製造的奈米粒子，殘留於環境中，危害生物。有越來越多的研究指出，物質奈米化以後會侵犯生物，引起發炎反應，產生生物毒性。探討奈米粒子和生物分子之間的交互作用，可以釐清奈米粒子毒性問題，預防奈米毒性的傷害，提供奈米粒子應用在生物上的基礎性研究。 金具有最好的生物相容性，加上奈米金粒子大小能準確的被控制，對於物質因尺度奈米化產生的毒性，以及奈米粒子和生物分子間交互作用的探討，是研究奈米毒性的理想材料。 GNPs毒性的強度以及誘發免疫反應，與GNPs粒徑大小有著顯著的關係。我們在一系列GNPs粒徑大小不同的實驗中，發現5 nm GNPs 會引起強烈的免疫反應，8 nm and 12 nm GNPs能大量停留在脾臟中，施打17 nm and 37 nm GNPs的老鼠會出現衰竭的現象，17 nm GNPs會影響老鼠學習記憶能力，50 nm and 100 nm GNPs無毒亦不會引起免疫反應的，這些現象證實了生物-奈米作用力與生物反應緊緊相扣的關係。 我們利用這些重要的訊息，建構生物-奈米間作用力的基礎研究，包含奈米金粒子在生物體內，免疫、毒性反應及其預防，探討免疫球蛋白作用力並利用免疫球蛋白自由控制奈米材料。具體細項如下:一.奈米金粒子的毒性與其在對臟器的影響。二. 奈米金粒子通過血腦屏障，影響學習記憶能力，利用黑色素可以預防奈米金粒子在腦組織的奈米毒性。三. 量測免疫球蛋白摺疊特性 四. 探討抗體與奈米金粒子的單分子作用力。五. 開發奈米金粒子作為理想的疫苗載體。六. 以生物免疫方式製備可以偵測環境中奈米粒子的感測器。七. 利用奈米-生物的作用力，在奈米尺度下操制矽奈米線。八. 奈米金粒子修飾矽奈米線場效電晶體病毒檢測器。 我們利用奈米金粒子，證實奈米毒性的產生，與粒子尺寸大小有著密切的關係，並以奈米微觀的角度，呈現生物分子摺疊特性，探討奈米-生物之間的交互作用力。 奈米材料的優異特性，在生物體外已經成功地被運用，但是，在生物體內的應用，仍然欠缺基礎性的研究。奈米毒性的特性探討，以及奈米粒子和生物分子之間交互作用的研究，是重要的研究課題。我們必須意識到，精細複雜的交互作用力，可能會降低奈米載體的效用，限制奈米粒子的傳遞，影響奈米粒子的生物分布；材料因奈米化，伴隨而來的副作用或毒性反應，決定著奈米材料可否能安全的應用在生物體上。

What is the specialty of bio-toxicity caused by nanoparticles? How is the interaction between nanoparticles and bio-molecules? And how do we use this specialty in further applications? Nanotechnology has been widely developed in recent years and has been used for fabrication in high-quantity of nanoparticles, which remains in the environment and also endanger to the livings. Many researches have revealed that when the size of the matter decreases to nanoscale, matter would invade into the livings and would cause severe inflammation and bio-toxicity. We have investigated the interaction between nanoparticles and bio-molecules, to help and understand the toxicity of nanoparticles and preventing the damage. Gold nanoparticles have the best biocompatibility and we can precisely control the size of gold nanoparticles. Because of the unique size effect leading to bio-toxicity and interesting interaction between nanoparticles and biomolecules, a number of serious concerns have been raised about what effects these will have on our society if realized, and what action if any is appropriate to mitigate these risks.The major theme of this thesis can be separated into 9 sections: 1. Assessment of the in vivo toxicity of gold nanoparticles: we found that The toxicity of GNPs may be a fundamental determinant of the environmental toxicity of nanoparticles. 2. Gold nanoparticles pass through the blood-brain barrier and impair learning and memory in mice: we found that the ability of GNPs to damage cognition in mice is size-dependent and is associated with their ability to invade the hippocampus. 3. Measuring the flexibility of immunoglobulin by gold nanoparticles: we found a novel platform to measure the functional flexibility of immunoglobulin. 4. Contribution of hinge flexibility to the antibody/ nanoparticle recognition: we found that two levels of affinity selection were disclosed. It is obvious that there exist only certain structural ranges that would allow the best binding between 2 FAB fragments and the surface of 5-nm GNP. 5. Detection of gold nanoparticles using immunoglobulin-coated piezoelectric sensor: we provide an immunoglobulin-based nanoparticle sensor thus provides a direct and economical solution. 6. Antibody-guided nanofabrication: inserting silicon nanowires into nanopores: we made use of antibodies that interacted with gold nanoparticle-coated nanowires to guide the insertion into nanopores. The successful application of antibody-antigen interactions provides a novel approach to manipulate objects at the nanoscale. 7. Label-free and ultra-sensitive detection of the cymbidium mosaic virus with an antibody-functionalized nanowire field effect transistor: we found that the detection of CymMV provides an ultra-sensitive and time-efficient platform for the protection of Orchidaceae from this virus. 8. Assessment for the size-dependent poperties of gold nanoparticles as a vaccine carrier to elicit a focused and enhanced antibody response against synthetic Foot-and-mouth disease virus peptide: we found that GNPs ranging from 8 nm to 17 nm may serve as an ideal carrier to elicit focused antibody response against a synthetic pFMDV peptide. There has been a great progress in the field of nanotechnology which impacts every field of science as well as in our daily life. An understanding of nanotoxicity and bio-nano interaction could lead to the harnessing of nanotechnology properties. The nanotechnology will bring much more convenience to our life.