Photocytotoxicity and Magnetic Relaxivity Responses of Dual-Porous 纬-Fe2O3@meso-SiO2 Microspheres

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• 作者：Shou-hu Xuan ; Siu-Fung Lee ; Janet Ting-Fong Lau ; Xiaoming Zhu ; Yi-Xiang J. Wang ; Feng Wang ; Josie M. Y. Lai ; Kathy W. Y. Sham ; Pui-Chi Lo ; Jimmy C. Yu ; Christopher H. K. Cheng ; Ken Cham-Fai Leung
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：April 25, 2012
• 年：2012
• 卷：4
• 期：4
• 页码：2033-2040
• 全文大小：472K
• 年卷期：v.4,no.4(April 25, 2012)
• ISSN：1944-8252

文摘

Novel high magnetization microspheres with porous 纬-Fe₂O₃ core and porous SiO₂ shell were synthesized using a templating method, whereas the size of the magnetic core and the thickness of the porous shell can be controlled by tuning the experimental parameters. By way of an example, as-prepared 纬-Fe₂O₃@meso-SiO₂ microspheres (170 nm) display excellent water-dispersity and show photonic characteristics under externally applied a magnetic field. The magnetic property of the 纬-Fe₂O₃ porous core enables the microspheres to be used as a contrast agent in magnetic resonance imaging with a high r₂ (76.5 s^鈥? mM^鈥? Fe) relaxivity. The biocompatible composites possess a large BET surface area (222.3 m²/g), demonstrating that they can be used as a bifunctional agent for both MRI and drug carrier. Because of the high substrate loading of the magnetic, dual-porous materials, only a low dosage of the substrate will be acquired for potential practical applications. Hydrophobic zinc(II) phthalocyanine (ZnPC) photosensitizing molecules have been encapsulated into the dual-porous microspheres to form 纬-Fe₂O₃@meso-SiO₂鈥揨nPC microspheres. Biosafety, cellular uptake in HT29 cells, and in vitro MRI of these nanoparticles have been demonstrated. Photocytotoxicity (位 > 610 nm) of the HT29 cells uptaken with 纬-Fe₂O₃@meso-SiO₂鈥揨nPC microspheres has been demonstrated for 20 min illumination.

Keywords:

drug carrier; magnetic resonance imaging; nanoparticle; photocytotoxicity; porosity