Surface functionalization of SBA-15 nanorods for anticancer drug delivery

SBA-15 nanorods with high surface area (1010 m² g⁻¹) were functionalized by post grafting method with three different alkoxysilanes including (3-aminopropyl) triethoxysilane (APTES), 3-bis(2-hydroxyethyl)amino] propyl triethoxysilane (HAPS) and 3-2-(2-aminoethylamino) ethylamino] propyl trimethoxysilane (AEPS). The prepared materials were used as nanocarriers for an anticancer drug (gemcitabine). The obtained samples were characterized by SAXS, elemental analysis, TGA, N₂ adsorption/desorption, SEM, TEM, FTIR and UV spectroscopies. The adsorption and release properties of all samples were investigated. It was found that the surface functionalization increases the interaction between the carrier and gemcitabine and results in the loading enhancement of the drug. In addition, the adsorption of gemcitabine on the modified mesoporous matrix depends on the type and the amount of alkoxysilanes groups. The maximum content of the deposited drug in the modified SBA-15 nanorods is close to 22 wt.%. The rate of the drug release from the modified samples containing NH₂ groups on their surfaces is pH dependent.