A New Bioprinted Dual-Layered Corneal Structure Using Collagen-Based Bioinks

Bioengineered corneal constructs are a promising solution to the global shortage of donor tissue. However, most current models lack anatomical curvature and appropriate extracellular matrix (ECM) composition of the native cornea, limiting their relevance for studying graft integration and stromal-endothelial interactions. In this study, we developed a bioprinted, dual-layer corneal model comprising corneal stromal cells laden in type I collagen (Col-I) and a monolayer of corneal endothelial cells supported by collagen type IV (Col-IV). The construct was printed onto a curved support to replicate the posterior curvature of the native cornea. The use of ECM-specific, human-derived collagen bioinks supported high cell viability (>90%) and the formation of a continuous endothelial layer. Histological and immunofluorescence analyses confirmed distinct layering and appropriate cellular morphology and phenotypic marker expression for both corneal stromal and endothelial cells. The construct retained its curvature, transparency, and interfacial integrity over 3 weeks in culture and demonstrated adherence when positioned over an ex vivo corneal tissue. This anatomically curved, multilayered in vitro model offers a physiologically relevant platform for exploring stromal-endothelial architecture and cell interaction in corneal tissue engineering applications.