Ultrasound, pH, and Magnetically Responsive Crown-Ether-Coated Core/Shell Nanoparticles as Drug Encapsulation and Release Systems

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• 作者：Siu-Fung Lee ; Xiao-Ming Zhu ; Yi-Xiang J. Wang ; Shou-Hu Xuan ; Qihua You ; Wing-Hong Chan ; Chi-Hin Wong ; Feng Wang ; Jimmy C. Yu ; Christopher H. K. Cheng ; Ken Cham-Fai Leung
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：March 13, 2013
• 年：2013
• 卷：5
• 期：5
• 页码：1566-1574
• 全文大小：552K
• 年卷期：v.5,no.5(March 13, 2013)
• ISSN：1944-8252

文摘

Core@shell nanoparticles with superparamagnetic iron oxide core, mesoporous silica shell, and crown ether periphery were fabricated toward drug delivery and tumor cell imaging. By the concept of nanovalve based on supramolecular gatekeeper, stimuli-responsive drug delivery nanosystems Fe₃O₄@SiO₂@meso-SiO₂@crown ethers were synthesized by (i) modified solvothermal reaction; (ii) sol鈥揼el reaction; and (iii) amide coupling reaction. The successful coupling of the dibenzo-crown ethers onto the mesoporous silica shell was confirmed by thermogravimetric analysis and Infrared spectroscopy. In this system, the 鈥淥N/OFF鈥?switching of the gatekeeper supramolecules can be controlled by pH-sensitive intramolecular hydrogen bonding or electrostatic interaction (such as metal chelating). Biological evaluation of the nanoparticles renders them noncytotoxic and can be uptaken by L929 cells. In this work, the antitumor drug (doxorubicin) loading and release profiles which were studied by the UV/visible absorption spectroscopy. The mechanism involves the best-fit binding of crown ethers with cesium or sodium ions at different pH values with ultrasonic wave in phosphate buffered saline (PBS). Magnetic resonance imaging analysis of the particles reveals a high relaxivity, rendering them potentially useful theranostic agents.

Keywords:

crown ether; drug carrier; magnetic resonance imaging; nanoparticle; ultrasound