Cell Compatibility of Three-Dimensional Porous Barium-Cross-Linked Alginate Hydrogels

Abstract

We attempted to clarify whether the suitability of three-dimensional porous barium-ion-crosslinked alginate (Ba-alginate) gels as a scaffold for cells, in comparison with calcium-ion-crosslinked alginate (Ca-alginate) gels, differed according the type of method used to induce cross-linkage. We fabricated two types of three-dimensional porous Ba- and Ca-alginate gels in which the alginates were cross-linked under freeze-dried conditions or in aqueous solution, and evaluated their affinity for cells. Only Ba-alginate, cross-linked by freeze-drying, exhibited a rough surface and high protein adsorption ability, in comparison with Ba-alginate that had been cross-linked in aqueous solution, and any type of Ca-alginate gel. Cells formed multicellular spheroids whenever alginate was used as a scaffold, but only on Ba-alginate porous gels cross-linked by freeze-drying did the number of cells increase with culture time. These findings indicate that the properties of Ba-alginate influencing its suitability as a scaffold for cells change according to the method used to induce cross-linkage. Our findings may be useful for extending the application of Ba-alginate, and may have significance in diverse biomedical fields.