Effect of a matrigel sandwich on endodermal differentiation of human embryonic stem cells.

Definitive endoderm can be derived from human embryonic stem cells using low serum medium with cytokines involved in the epithelial-to-mesenchymal transition, including Activin A and Wnt3A. The purpose of this study was to develop an improved protocol that permits the induction of definitive endoderm while avoiding the high rate of cell death that often occurs with existing protocols. By including insulin and other nutrients, we demonstrate that cell viability can be preserved throughout differentiation. In addition, modifying a matrigel sandwich method previously reported to induce precardiac mesoderm allows for enhanced endodermal differentiation based on expression of endoderm-associated genes. The morphological and migratory characteristics of cells cultured by the technique, as well as gene expression patterns, indicate that the protocol can emulate key events in gastrulation towards the induction of definitive endoderm.