Synthesis and application of amino-modified silicas containing albumin as hemoadsorbents for bilirubin adsorption

• Amino-modified silicas can immobilize more amount of BSA than non-modified silica.
• The BSA which was used in sol–gel process increases BET surface and pore size of silica.
• APTMS improves the selectivity of silica surface to albumin molecules.
• Modification of silica surface by albumin increases the adsorption ability for BR.

The organic–inorganic composite materials based on mesoporous silica containing bovine serum albumin (BSA) were synthesized using sol–gel method. According to the sol–gel process the surface of silica was modified by amino-groups using 3-aminopropyltrimethoxysilane (APTMS). This modification increased the selectivity to the albumin molecules due to special intermolecular interactions between amino groups of silica and carboxyl groups of BSA. The obtained silicas were characterized by nitrogen adsorption–desorption analysis, fourier transformed infrared spectroscopy, scanning electron microscopy. It was shown that encapsulation of the BSA inside silica matrix leads to the formation of mesoporous materials with high pore diameter (10–14 nm for albumin modified silicas) and a BET surface area equals to 346 ± 17 m2/g. The obtained materials were used as adsorbents for selective bilirubin removal. Analysis of adsorption isotherms showed that the adsorption ability to bilirubin depends on the amount of BSA grafted into silica particles. As a result, the amino-modified silica containing 70 mg/g of BSA is characterized by the highest bilirubin adsorption capacity. Thus, the obtained results showed the potential application of these adsorbents in medicine for toxins removal and treatment of hyperbilirubinemia.