Rapid 3D bioprinting of a multicellular model recapitulating pterygium microenvironment

This study developed a rapid, high-resolution digital light processing (DLP)-based 3D bioprinting workflow to create the first reported multicellular in vitro pterygium model that recapitulates key pathological hallmarks of pterygium, including chronic inflammation, angiogenesis, and epithelial–mesenchymal transition (EMT). Primary human conjunctival stem cells (hCjSCs) were isolated from donor tissue and expanded using a feeder-free small-molecule cocktail (CjSCM) designed to preserve stemness and proliferation while reducing mesenchymal drift. The authors then bioprinted microscale GelMA-based hydrogel constructs that maintained high hCjSC viability, stem cell marker expression, and goblet-cell differentiation capacity. To model the pterygium microenvironment, a multilayer construct was bioprinted combining (i) hCjSCs with macrophages to mimic inflammatory infiltration and (ii) HUVECs with fibroblasts to mimic angiogenic remodeling, producing vascular marker expression consistent with microvasculature formation. RNA-seq of hCjSCs recovered from the multicellular 3D model revealed large transcriptomic shifts versus 2D controls, including enriched inflammatory signaling (e.g., TNF/NF-κB and interleukin-associated programs), EMT signatures, and pathway changes linked to pterygium recurrence (e.g., TGF-β/BMP signaling). Cross-comparison with public RNA-seq datasets from patient-derived pterygium tissue showed the 3D model clustered more closely with diseased tissue than 2D conjunctival controls, supporting its disease relevance. Overall, the platform provides a scalable, reproducible, and clinically translatable approach for mechanistic studies and future drug screening in an ocular surface disease context.