Article pubs.acs.org/JPCC
Correlating Surface-Functionalization of Mesoporous Silica with Adsorption and Release of Pharmaceutical Guest Species Victoria Morales,† Matthew N. Idso,‡ Moisés Balabasquer,† Bradley Chmelka,*,‡ and Rafael A. García-Muñoz*,† †
Group of Chemical and Environmental Engineering, ESCET, Rey Juan Carlos University. C/Tulipán s/n, 28933 Móstoles, Madrid, Spain ‡ Department of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States S Supporting Information *
ABSTRACT: We present here a detailed molecular-level understanding of the interactions among surface-functionalized mesoporous SBA-15 silica and pharmaceutical guests that influence macroscopic adsorption and release behaviors. A model drug species, methylprednisolone sodium succinate, was adsorbed on the surfaces of functionalized mesoporous SBA-15 silica materials with different aminoalkyl species and without or with C60 fullerene moieties. Zeta potential measurements show that the electrostatic interactions among methylprednisolone species and modified silica surfaces are important for the adsorption and release of the methylprednisolone molecules. Complementary one and two-dimensional (2D) solid-state 13C{1H} NMR measurements provide evidence for specific intermolecular interactions between adsorbed methylprednisolone species and different types of functionalized silica surfaces. In particular, correlated 13 C and 1 H signal intensities from the methylprednisolone alkyl moieties and the aminoalkyl groups of the functionalized silica surfaces unambiguously establish their close (
