MCM-41 silica with spherical morphology and small particle sizes (100 nm) was synthesized and modified by post-synthesis method with amino and/or carboxylic groups. Solid state reaction was applied for the first time for loading of poorly soluble drug mesalazine (5-aminosalicylic acid – 5-ASA). Thenon-loaded and drug loaded mesoporous silicas were characterized by XRD, TEM, N2 physisorption, elemental analysis, thermal analysis, FT-IR and solid state NMR spectroscopy. Quantum-chemical calculations were used to predict the interactions between the drug molecule and the functional groups of the carrier. The nanoparticles were post-coated with sodium alginate and the coating modified the rate of mesalazine release from MCM-41NH2 and MCM-41NH2COOH particles. Cytotoxic evaluation on colon adenocarcinoma cell line revealed that the alginate coating reduced cytotoxicity of mesalazine loaded in the post-coated particles compared to the pure mesalazine. The functionalized, polymer coated mesoporous systems are suitable oral drug delivery systems providing an opportunity to modify drug release
