Niche-inspired synthetic matrices for epithelial organoid culture

Epithelial organoids are now an important tool in fields ranging from regenerative medicine to drug discovery. Organoid culture requires Matrigel, a complex, tumor-derived, extracellular matrix. An alternative completely synthetic matrix could improve culture reproducibility, clarify mechanistic phenomena, and enable applications involving human implantation. Here, we designed synthetic matrices with tunable biomolecular and biophysical properties that allowed us to identify critical gel parameters in organoid formation. Inspired by known epithelial integrin expression in the proliferative niche of the human intestine, we identified an α2β1 integrin-binding peptide as a critical component of the synthetic matrix that supports human duodenal colon and endometrial organoid propagation. We show that organoids emerge from single cells, retain their proliferative capacity, are functionally responsive to basolateral stimulation and have correct apicobasal polarity upon induction of differentiation. The local biophysical presentation of the cues, rather than bulk mechanical properties, appears to be the dominant parameter governing epithelial cell proliferation and organoid formation in the synthetic matrix.