Tissue engineered organoid co-culture model of the cycling human endometrium in a fully-defined synthetic extracellular matrix

The human endometrium is a mucosal barrier that undergoes cycles of growth, differentiation, and breakdown in response to sex hormone fluctuations. Dynamic tissue responses to hormones are primarily driven by epithelial-stromal communication and its dysregulation is linked to myriad gynecological disorders. The lack of robust in vitro models for the long-term 3D co-culture of patient-derived endometrial epithelial and stromal cells hinders dissection of this crosstalk and thus impairs progress in disease treatment. Here, we describe a versatile synthetic extracellular matrix tailored to the endometrium that enables the in vitro modeling of human healthy and disease states across the menstrual cycle. We used a tissue-inspired approach to semi-empirically screen a parameter space that encompasses the biophysical and molecular features of the endometrial microenvironment. Leveraging cell-specific integrin expression profiles, we defined a modular polyethylene glycol (PEG)-based hydrogel that fosters hormone-driven expansion and differentiation of epithelial organoids co-cultured with stromal cells. Characteristic morphological and molecular responses of each cell type to hormone changes were observed when cells were co-encapsulated in hydrogels tuned to a stiffness regime similar to the native tissue and functionalized with a collagen-derived adhesion peptide (GFOGER) and a fibronectin-derived peptide (PHSRN-K-RGD). Using transcriptomic and functional assays, we demonstrate the system’s ability to recapitulate menstrual-cycle specific reproductive events and identified that inflammation-induced dysregulation of epithelial proliferation is mediated via the stromal compartment. Altogether, we demonstrate the development of a fully synthetic matrix to sustain the dynamic changes of the endometrial microenvironment and support its applications to understand endometriotic diseases. ![Figure][1] Graphical abstract ### Competing Interest Statement L.G.G. and V.H.G. have a patent application pending related to the hydrogel system. The rest of the authors have no competing interests. [1]: pending:yes