Magnetically Sensitive Alginate-Templated Polyelectrolyte Multilayer Microcapsules for Controlled Release of Doxorubicin

Magnetically sensitive alginate-templated polyelectrolyte multilayer microcapsules were successfully synthesized by a novel process combining emulsification and layer-by-layer self-assembly techniques. The as-synthesized microcapsules (2.67 mu m in diameter) were superparamagnetic with a saturation magnetization of 14.2 emu.g(-1), which contained approximately 30 wt % maghemite nanoparticles. The drug (doxorubicin) encapsulation efficiency was 56.4% and loading content was 3.5%. The in vitro release behavior under a high-frequency magnetic field (HFMF) indicated that the applied HFMF accelerated significantly the drug release from the microcapsules, which might be related to the microcapsules' magnetic properties. Moreover, the in vitro cytotoxicity of doxorubicin-loaded alginate-templated polyelectrolyte multilayer microcapsules and the doxorubicin released from the microcapsules were investigated.