Controlled release of growth factor from bijels-derived hybrid hydrogel membranes

Abstract

Bicontinuous interfacially jammed emulsion gels (bijels) are newly discovered structures consisting of two interpenetrating continuous liquid phases. Bijels can be used as templates for fabricating bijels-derived materials, maintaining the bicontinuous microstructure in the solid form. The bicontinuous architecture makes bijels-derived materials attractive for biomedical applications. In tissue engineering, the local delivery of growth factors enhances tissue regeneration. This study investigated the fabrication of hybrid hydrogel membranes of biocompatible materials via bijels templates and the incorporation and release of vascular endothelial growth factor (VEGF) from the membranes. Bijels membranes were made using the solvent transfer-induced phase separation technique. Hexanedioldiacrylate was the oil phase in bijels and was cured by UV. After curing, bijels membranes were immersed in VEGF-containing Na-alginate solutions for forming continuous alginate phase in membranes, and alginate was then crosslinked by a CaCl2 solution. Release experiments of VEGF were performed by immersing membranes in a simulated body fluid for different times. VEGF concentrations in the test liquid were measured using human VEGF ELISA kit assay and the VEGF in vitro release profiles were established. Controlled released of VEGF could be achieved with optimized processing parameters for hybrid hydrogel membranes.