E-/VE-Cadherin-Fc Interface Programs Gli-1+ Stromal Cells for Assembly With Functionalized Microparticles Into 3D Renal Fibrotic Microtissues for Drug Screening.

Renal fibrosis lacks experimentally tractable human-relevant models that integrate defined stromal programming with spatially controlled profibrotic cues. Here, we developed a dual E-/VE-cadherin-Fc (EVE) interface to condition human mesenchymal stem cells (MSCs) under CTGF/TGF-β stimulation. Cells showed increased expression of Gli-1, NG2, PDGFRβ, and FAP and activated transcription of extracellular matrix remodeling. These changes were consistent with the acquisition of a Gli-1+ perivascular-like profibrotic stromal phenotype, and were accompanied by reorganization of cadherin-catenin complexes, actin cytoskeletal rearrangement, and increased YAP nuclear localization. Cell-sized PLGA/chitosan-heparin microparticles were subsequently functionalized with E-/VE-cadherin-Fc and loaded with CTGF/TGF-β. Co-assembly of these microparticles with the conditioned stromal cells (gMSCs) and renal epithelial cells (HK-2) generated 3D renal fibrotic microtissues that combined cadherin-mediated adhesive presentation with localized cytokine delivery. The resulting microtissues exhibited a broader distribution of α-SMA, Collagen I, and Fibronectin, together with reciprocal epithelial-stromal signaling and spatially organized fibrotic activation. As a proof of concept for pharmacological evaluation, the microtissues responded to pirfenidone (PFD) in a dose-dependent manner, with 100 µM PFD reducing α-SMA expression by ∼73% while preserving microtissue viability. Together, these findings establish a material-enabled, cadherin-guided strategy for constructing disease-relevant stromal organization and spatially controlled profibrotic signaling in human renal fibrosis models.