Effects of different pore structures on loading and sustained-release of mitomycin C by hollow mesoporous Fe(0)@mSiO2

Herein, we developed the dual-function template method to fabricate hollow magnetic nano-spheres (denoted as HMFe–Si–C n , n = 16, 18) with a mesoporous shell and hollow interior structure using alkyl chain trimethoxysilane templating. The shorter chain template directed formation of HMFe–Si–C 16 with size of 119 nm, having disordered inkbottle type mesopores and saturation magnetization of 50.01 emu/g higher than that of HMFe–Si–C 18 with cylindrical type mesopores. In addition, the HMFe–C n loaded with MMC diaplays a pH and magnetic dual responsive drug release behavior. By contrast, Mitomycin C (MMC) loading efficiency of HMFe–Si–C 16 was higher owing to the fact that the pore size, surface area, and pore volume of HMFe–Si–C 16 were larger than those of HMFe–Si–C 18 . Besides, MMC loaded HMFe–Si–C n hollow spheres showed a clear pH-dependent drug release behavior, having a higher release rate in acidic environments of pH 5.7. For the pH 5.7 and 7.4 release, the release kinetic for HMFe–Si–C 16 –MMC composites follows pseudo-first-order attributable to its special pore structure. With Fe(0) as a core, HMFe–Si–C n is distinguished for higher magnetic properties, and it is more conducive to magnetic targeted treatment of cancer cells and can release drugs through external magnetic field. In addition, HMFe–Si–C n has lower cytotoxicity and better biocompatibility. For this reason the inner cavity of HMFe–Si–C 16 could be labeled with radioisotope 99 Tc m to study the magnetic targeting distribution of HMFe–Si–C 16 in vivo, and its cytotoxicity against in vitro HeLa cells was also studied. These results indicate the potential of HMFe–Si–C 16 in the magnetic targeted drug delivery system.