Department of Chemistry
Photocytotoxicity and magnetic relaxivity responses of dual-porous γ-Fe2O3@meso-SiO2 microspheres
Novel high magnetization microspheres with porous γ-Fe 2O 3 core and porous SiO 2 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 γ-Fe 2O 3@meso-SiO 2 microspheres (170 nm) display excellent water-dispersity and show photonic characteristics under externally applied a magnetic field. The magnetic property of the γ-Fe 2O 3 porous core enables the microspheres to be used as a contrast agent in magnetic resonance imaging with a high r 2 (76.5 s -1 mM -1 Fe) relaxivity. The biocompatible composites possess a large BET surface area (222.3 m 2/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 γ-Fe 2O 3@meso-SiO 2-ZnPC microspheres. Biosafety, cellular uptake in HT29 cells, and in vitro MRI of these nanoparticles have been demonstrated. Photocytotoxicity (λ > 610 nm) of the HT29 cells uptaken with γ-Fe 2O 3@meso-SiO 2-ZnPC microspheres has been demonstrated for 20 min illumination. © 2012 American Chemical Society.
drug carrier, magnetic resonance imaging, nanoparticle, photocytotoxicity, porosity
Source Publication Title
ACS Applied Materials and Interfaces
American Chemical Society
Link to Publisher's Edition
Xuan, Shou-Hu, 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, and Ken Cham-Fai Leung. "Photocytotoxicity and magnetic relaxivity responses of dual-porous γ-Fe2O3@meso-SiO2 microspheres." ACS Applied Materials and Interfaces 4.4 (2012): 2033-2040.