Preparation of Magnetic Hollow Mesoporous Silica Spheres and Their Drug Delivery Property

Core-shell Fe3O4@SiO2hollow mesoporous spheres with large cavities were successfully prepared by using the n-octadecyltrimethoxysilane(C18TMS)as the templates at room temperature.The nanospheres are well monodisperse and nearly uniform.The N2sorption analysis indicated that the Brunauer-Emmett-Teller(BET)surface area reaches 1001m2/g and the Barrett-Joyner-Halanda(BJH)pore volume reaches 0.994cm3/g,and only one Fe3O4particle of ca.20nm in diameter is encapsulated in each sphere.The magnetic measurement indicated that the Fe3O4@SiO2hollow mesoporous spheres exhibited ferromagnetic behavior with the magnetization saturation of 14.5emu/g.When Aspirin was loaded,the material showed high drug loading capacity of 34wt%.Therefore,this kind of magnetic hollow mesoporous spheres provides to be a very promising nanocarrier in a targeted drug delivery system.