Thermosensitive and Drug-Loaded Ordered Mesoporous Silica: A Direct and Effective Synthesis Using PEO-b-PNIPAM Block Copolymers

An ecofriendly and straightforward approach to prepare PNIPAM-functionalized mesoporous hybrid silica materials is described: the use of PEO-b-PNIPAM diblock copolymers, specifically designed to act as efficient structure-directing agents (SDA) in silica synthesis, led directly to functionalized hybrid silica materials, whose mesoporosity was subsequently created by washing the material in water in appropriate conditions. Drug-loaded mesoporous silica materials are usually obtained by impregnating such hybrid materials in a drug-containing organic solvent. To avoid such a step, an alternative strategy for the direct incorporation of a hydrophobic drug (i.e., during the synthesis of the hybrid material) was successfully attempted. Finally, the effect of temperature on the release rate of the drug, which appears to be quite slow, was investigated.