Uterine pathologies resulting from locally perturbed hormone signaling, including infertility and ectopic uterine growth causing endometriosis, impact nearly 10% of women in their reproductive years. In vitro models of the endometrium offer promise to study hormonally regulated paracrine signaling and potential therapeutic interventions. However, long-term in vitro cell culture models to study epithelial-stromal paracrine signaling are hampered by the lack of a robust, adaptable extracellular matrix (ECM) scaffold capable of sustaining multiple cell types in a physiological environment over timescales relevant to studying hormonally dynamic responses. Our objective is to dramatically improve the ease, reproducibility, and functionality of 3D endometrial co-cultures for use in mechanistic studies of endometriosis by developing an entirely synthetic ECM that recapitulates the desirable features of natural basement membrane in fostering polarized endometrial epithelia and supports stromal differentiation. 

Identification of a branched fibronectin peptide containing both the RGD and synergy domains from the fibronectin III 9,10 domains along with peptides that bind fibronectin, collagen IV and laminin were sufficient to support long-term (weeks) viable endometrial co-cultures that displayed hormone mediated decidualization (Fig. 1a) and enhance ECM accumulation with the presence of matrix binding peptides (Fig. 1b).