In this report we show that drug incubation temperature, methods used for removing surfactant templates from mesoporous materials and solvents used for placing surface organic functional groups on the materials can improve or affect the adsorption capacity and drug release properties of potentially useful nanoporous silica and organosilica as drug delivery vehicles. This is demonstrated by investigating the adsorption and release properties toward rhodamine 6G (R6G) and an anticancer drug, cisplatin, of various solvent-extracted and calcined mesoporous silicas (MCM-41 and SBA-15), organic-functionalized mesoporous silicas containing terminal organoamine, organothiol and vinyl groups, and bridging organic-functionalized ethane periodic mesoporous organosilica (ethane PMO) under various conditions. Two different solvents, isopropanol and toluene, were used to graft the terminal organic groups from their corresponding organosilanes, producing materials with slightly different adsorption and release properties. The adsorption capacities of the organic-functionalized mesoporous silicas that were prepared from a well solvent-extracted MCM-41 increased significantly as the temperature was raised from room temperature to 50 and 75 °C. Furthermore, samples with a higher percent adsorption of R6G and cisplatin also showed higher overall percent release of the adsorbed R6G or cisplatin molecules in a simulated body fluid (SBF) solution. Interestingly, the ethane PMO also showed significantly higher adsorption capacity for both R6G and cisplatin than the control samples, MCM-41 or SBA-15. Raising the temperature improved the adsorption capacity of ethane PMO, for both R6G and cisplatin. The method used to remove the surfactant templates from the parent mesostructured materials was also found to affect the materials’ adsorption properties.

A synthetic method for controlling the Henry reaction products from nitrostyrene to nitroalcohol in heterogeneous catalysis by a simple change of the catalytic sites in organoamine-functionalized mesoporous catalysts is reported. The synthesis resulted in either b-nitrostyrene or b-nitroalcohol by simple change of the types of amine functional groups in the amine-functionalized mesoporous catalysts from primary amines into secondary or tertiary.

A series of mesoporous nanosphere materials that are functionalized with various terminal and bridging organic groups were synthesized. They have improved adsorption capacity and different release properties for drug and small molecules. The materials contained terminal vinyl, 3-mercaptopropyl, 3-aminopropyl, and secondary amine functional groups and bridging ethane, ethene, and benzene groups within their mesopore channel walls. The samples containing mercaptopropyl and vinyl groups showed greater adsorption capacity and better controlled release behavior for rhodamine 6G molecules. On the other hand, mesoporous matrices containing amine functional groups showed higher adsorption capacity and better release properties for ibuprofen molecules. Further studies revealed that the bridging organic groups in the mesopore channel walls also improved the adsorption capacity and release properties of the materials compared to the corresponding samples containing no bridging organic groups. Such improved adsorption and controlled release properties of molecules by simple changes of functional groups on mesoporous materials are important for the development of nanomaterial drug delivery vehicles and for controlled release of drugs over long time periods at specific targeted sites in the body. By judicious choice of organic groups and by systematic design and synthetic approaches, nanoporous materials having different adsorption capacity and release properties for many other drug molecules can also be achieved.

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