Competitive inhibition of protein adsorption to silica surfaces by their coating with high density charge...

The adsorption of proteins to silica surface is a common process mainly governed by the electrostatic attractive interaction between the pH-dependent negatively silica surface and the positive charges of the biomolecule. This process often reduces the conformational stability of the adsorbed protein and may reduce its biological functionality mostly due to multimolecular processes such as aggregation and fibrillation. Here we show that high-density charge cationic polyelectrolytes may successfully compete with the protein for the silica surface containing deprotonated-silanol groups. Therefore, the coating of silica surfaces with these cationic polyelectrolytes precludes the adsorption of the protein to the solid surface. Intensive water washing of the polyelectrolyte-coated silica surfaces had does not result in polyelectrolyte release (even at moderate ionic strength) maintaining the solid surface protected from protein adsorption.