Synthesis and characterization of MCM-41 spheres inside bioactive glass–ceramic scaffold

Composite systems have been prepared, combining the drug up-take and release properties of MCM-41 silica sub-micron spheres with those of a bioactive glass–ceramic macroporous scaffold belonging to the SiO2–CaO–K2O (SCK) system (potentially able to promote successful osteointegration in tissue engineering). The systems are prepared by dipping the glass–ceramic scaffold into the MCM-41 synthesis solution. To this purpose, the pH of the MCM-41 synthesis solution has been lowered with respect to the usual literature procedure to minimize the detrimental effects of the impregnation treatment on glass–ceramic scaffolds that were observed in a previous work by the author. MCM-41–SCK composite scaffolds have been characterized by means of XRD, N2 adsorption, thermogravimetry and Scanning Electron Microscopy (coupled with EDS analysis). The adsorption capacity toward ibuprofen, tested as model drug, is three times higher than that of the MCM-41-free scaffold, because of the presence of the ordered mesoporous silica. Also the release behaviour in SBF at 37^ ◦C is strongly affected by the presence of MCM-41 inside the scaffold macropores.