多功能氧化矽奈米粒子於生物上之應用

Abstract

近年來，隨著奈米生物科技的發展逐漸成熟，愈來愈多的研究團隊開發出個人化的奈米粒子。縱使每個團隊所選擇的材料不盡相同，毫無疑問地，開發一個兼具偵測診斷及治療的多功能奈米粒子仍是大家共同的目標。而在本研究中，我們成功發展出一個新穎的多功能氧化矽奈米複合材料(Mag-Dye@MSN)，並且推廣其應用至生物方面。 多功能氧化矽奈米複合材料組成： 1.中孔洞氧化矽材料：具有大表面積、大孔體積、均勻孔徑大小以及表面容易修飾的特性 (傳遞藥物、酵素及基因的優良載體)。 2.螢光分子：作為追蹤奈米粒子所在位置的探測器 (空間解析度佳)。 3.超順磁奈米粒子：磁振造影顯影劑 (非侵入性偵測)並可利用其磁性作為分離的功具。 於細胞應用層面：我們證實了Mag-Dye@MSN 可藉由細胞的內噬作用，有效的進入細胞體內。並檢視了奈米粒子表面電荷與其進入細胞途徑的關聯；於活體應用層面：藉由靜脈注射，我們成功的將Mag-Dye@MSN 送入小鼠體內，並於磁振造影儀下，看到顯著的顯影效果。這些初步實驗結果，支持我們相信此多功能氧化矽奈米複合材料 (Mag-Dye@MSN)，在未來的研究發展中極具潛力。

Mesoporous silica nanoparticles (MSN) with unique properties such as high surface area, uniform pore size, easy modification, and biocompatibility have made them suitable for biological applications. In previous reports, MSNs have been demonstrated to be cell markers, gene transfection and drug delivery agents. Although these cell-level studies are attractive, some important issues, such as the cellular uptake efficiency, toxicity and circulation behavior of MSN in living animals, have to be addressed for further practical animal-level applications. Superparamagnetic nanoparticles (i.e., magnetite) with diameter less than 25 nm exhibit an effective magnetic resonance imaging (MRI) contrast enhancement behavior. Because MRI is a noninvasive imaging method, it is a powerful tool to track the migration of cells and to investigate the distribution of nanoparticles in living body. But the main drawbacks of MRI technique are low sensitivity and resolution, which make it unable to provide detailed biological information. To offset the shortcoming and expand the bioimaging applications, attaching fluorescent probe (subcellular imaging) and MRI probe (noninvasive imaging) simultaneously to MSN is an important task. We adopt a strategy that simultaneously fuses the amorphous silica shell of Fe3O4@SiO2 nanoparticles with a fluorescein isothiocyanate (FITC) incorporated MSN. The utility of multifunctional Mag-Dye@MSN resides in their ability to combine organic/inorganic and diagnostic/therapeutic components within a nanoscaled size. Looking forward, we believe Mag-Dye@MSN could be a potential candidate for MRI contrast agent and targeted drug delivery.