Affiliations: [a] Institut für Angewandte Chemie, Brandenburgische Technische Universität Cottbus-Senftenberg, Senftenberg, Deutschland | [b] Institut für Biotechnologie, Brandenburgische Technische Universität Cottbus-Senftenberg, Senftenberg, Deutschland
Corresponding author: Katrin Salchert, Institut für Angewandte Chemie, Brandenburgische Technische Universität Cottbus-Senftenberg, Universitätsplatz 1, 01968 Senftenberg, Deutschland. Tel.: +49 3573 85811; Fax: +49 3573 85809; E-mail: Katrin.Salchert@b-tu.de.
Abstract: BACKGROUND:The provision of fully functional materials for tissue engineering also depends on the presentation of external signals for the targeted control of cell migration. In this context, the use of structural proteins and signal molecules from the native extracellular matrix offers great potential to successfully produce ready-to-use biomaterials. OBJECTIVE:We herein describe the first steps in the development of an immersion method, which aims at generating gradients of growth factors on compressed Collagen Type I (COL I) membranes. For process development, bovine serum albumin (BSA) was used. METHODS:By incubation of COL I membranes in 500μg/mL BSA solution for periods of 5 - 240 min, an adsorption isotherm was determined, which was used to control the immersion process. The actual immersion process was performed by a computer-controlled stepper motor that immersed a COL I membrane in 500μg/mL BSA solution within 20 min. RESULTS:A linear BSA gradient with a change in concentration from about 30 ng/mm2 to 100 ng/mm2 could be generated. CONCLUSIONS:The defined immersion of a COL I membrane in a BSA solution is a suitable technique to produce a gradual course of BSA amount on the membrane surface. Gradient generation requires knowledge of the adsorption isotherms for the considered system. The developed immersion process can be adapted for other proteins and deviating concentrations.
Keywords: Collagen Type I, BSA, protein gradient, immersion process, protein adsorption, cell migration