Control of drug release through the in situ assembly of stimuli-responsive ordered mesoporous silica with magnetic particles

A site-selective controlled delivery system for controlled drug release is fabricated through the in situ assembly of stimuli-responsive ordered SBA-15 and magnetic particles. This approach is based on the formation of ordered mesoporous silica with magnetic particles formed from Fe(CO)(5) via the surfactant-template sol-gel method and control of transport through polymerization of N-isopropyl acrylamide inside the pores. Hydrophobic Fe(CO)(5) acts as a swelling agent as well as being the source of the magnetic particles. The obtained system demonstrates a high pore diameter (7.7 nm) and pore volume (0.47 cm(3) g(-1)), which improves drug storage for relatively large molecules. Controlled drug release through the porous network is demonstrated by measuring the uptake and release of ibuprofen (IBU). The delivery system displays a high IBU storage capacity of 71.5 wt%, which is almost twice as large as the highest value based on SBA-15 ever reported. In vitro testing of IBU loading and release exhibits a pronounced transition at around 32 degrees C, indicating a typical thermosensitive controlled release.