Effect of the organization of mesoporous silica gels for the encapsulation of biomolecules

The main goal of this project is the study of the effect of the pore organization in silica gels synthesized via the sol-gel process on the encapsulation and release of biomolecules. Three different objectives were aimed by realizing three different series of silica nanoparticles syntheses: • To test the reproducibility of an installation consisting of four hydrothermal reactors • To see the effects of using different silica precursors on the pore organization • To analyze the influence of the amount and the addition time of the micelle expander Three out of the four hydrothermal reactors presented an adequate reproducibility for further syntheses. The three silica samples synthesized from different precursors present three different disorganized pore morphologies. The addition time of the micelle expander was proven to have an influence on the pore organization. The silica nanoparticles were characterized via FTIR analysis, nitrogen adsorption-desorption, thermogravimetric analysis (TGA), and transmission electron microscope (TEM). Ibuprofen was chosen as a model biomolecule for the encapsulation in silica gels and the release. It was encapsulated in the three different samples of silica to analyze the effects of surface chemistry in the release kinetics. In comparison with the literature, a small amount of ibuprofen was encapsulated in the silica. Ibuprofen presents a release burst during the first hour and is partially released. For the creation of silica films, two different strategies were used: • Silica films via dip coating • Dispersion of silica particles in different polymers Thin films were obtained using the first technique, whilst thicker gels were obtained in the second one. The films thickness was estimated via weight difference for the films synthesized via dip-coating, and via an electronic micrometer for the silica-polymer films. Our promising results help to open new perspectives in the biomaterials domain and, more specifically, in the biofunctionalization of matrices for bone tissue reconstruction.Outgoin