3D Extracellular matrix mimics: fundamental concepts and role of materials chemistry to influence the stem cell fate.

Synthetic 3D Extracellular Matrices (ECM) find application in cell studies, regenerative medicine and drug discovery. While cells cultured in a monolayer may exhibit unnatural behavior and develop very different phenotypes and genotypes than in vivo, great efforts in materials chemistry have been devoted to reproduce in vitro the in vivo cell mi-croenvironments, which requires a fine tuning of the biochemical and structural actors varying in a spatiotemporal fashion to regulate the cell fate. This review will present the fundamentals of ECM, cover the chemical and structural features of the scaffolds used to generate ECM mimics, discuss the nature of the signaling biomolecules required and exploited to generate bioresponsive cell microenvironments able to induce a specific cell fate, and highlights the syn-thetic strategies involved to create functional 3D ECM mimics.