Electrophoretic applications of sol–gel matrices

Abstract

Biological application of sol–gel matrices has been extensively used through doping process. However the bioactivity of these materials is impaired mainly by uneven distribution of the biological molecules into the sol–gel matrix. The main objective of the present study was to apply electrophoretic field in order to concentrate biomolecules alongside sol–gel surface in order to increase the interaction capability with external molecules. Two potential applications of an electrophoretic field on sol–gel matrices were demonstrated. Silica gels in solid and liquid states were used as an electrophoretic matrix. In the first application, cylindrical rods made of solid silica gel and filled with tracking dye at one end, were subjected to applied electrical field. A well-defined movement of the tracking dye was attained from one edge to the other under applied electrophoretic current through the sol–gel rod pores. In the second application, accumulation of small biomolecules at one pole was obtained in a liquid pre-gelation sol–gel matrix during its polymerization. In order to optimize biologically active compounds movement in electrical field applied to sol–gel matrixes, parameters of both sol–gel and electrophoretic processes were studied. Under optimal conditions, it was feasible to increase the concentration of small biomolecules at sol–gel surface and consequently to enhance their availability towards external reactants.