Template Curvature Influences Cell Alignment to Create Improved Human Corneal Tissue Equivalents

The cornea's precise organization is essential for vision, yet replicating its structure in vitro remains a challenge. Prior research has shown that corneal stromal cells require specific cues to align and secrete organized extracellular matrices. However, the role of substrate curvature in this process has remained unclear. While flat templates have been used to guide cell behavior, they often fail to produce native-like tissue architecture. This gap motivated the exploration of curved substrates as a novel strategy to influence cell orientation. No prior work had resolved whether curvature alone could drive corneal cell alignment. Existing methods rely on complex topographical features or biochemical signals to direct cell behavior. The lack of a simple, physical cue that mimics natural corneal curvature has limited progress in corneal tissue engineering. This paper introduces a new approach by testing whether curvature alone can guide cell alignment and matrix organization.

This study aimed to determine whether substrate curvature alone could guide the alignment of human corneal stromal cells and the formation of cornea-like tissue equivalents. The researchers focused on whether curved templates could replace traditional topographical or biochemical cues. They hypothesized that curvature could act as a sufficient physical cue to direct cell organization. The motivation stemmed from the need for simpler, more effective methods in corneal tissue engineering. By isolating curvature as a variable, the study sought to clarify its role in tissue formation. The goal was to produce organized, elastic corneal-like tissues without additional scaffolding. This approach could reduce the complexity of current tissue engineering techniques. The findings may contribute to a better understanding of how corneal cells respond to physical cues.

The researchers developed a biofunctionalized curved template to guide cell alignment. Human corneal stromal cells were cultured on this curved substrate to assess their orientation and matrix production. The curved tissues were compared with tissues grown on flat templates to evaluate differences in structure and composition. Collagen fibril alignment was analyzed using imaging techniques to determine structural organization. Gene expression levels of key corneal markers were measured to assess functional similarity to native tissue. Elastic modulus was quantified to evaluate mechanical properties of the engineered tissues. Epithelial cell growth was tested on curved tissues to assess their suitability as a corneal stromal base. The study avoided the use of scaffolds, crosslinkers, or additional topographical features to isolate curvature as the influencing factor.

Tissues grown on curved templates exhibited aligned collagen fibrils and a cornea-like shape. Gene expression of keratocan, lumican, decorin, ALDH3, and CHST6 was significantly higher in curved tissues compared to flat ones. The elastic modulus of curved tissues was significantly higher (p = 0.0001), indicating improved mechanical properties. These tissues maintained structural integrity without scaffolds or crosslinking agents. Epithelial cells successfully stratified and differentiated on curved stromal tissues. The curved tissues demonstrated a highly organized nanostructure, suggesting native-like organization. The study showed that curvature alone could guide cell alignment and matrix formation. These findings suggest that curved substrates can serve as a simple yet effective tool in corneal tissue engineering.

The study demonstrated that curvature alone is sufficient to align corneal stromal cells and guide matrix organization. Curved tissues exhibited native-like structure and composition without additional cues. The researchers propose that this approach could simplify corneal tissue engineering by reducing reliance on complex scaffolds. The findings suggest that substrate curvature can act as a primary physical cue for tissue formation. The study supports the idea that physical cues can direct cell behavior in tissue engineering. The results may help improve in vitro models of corneal biosynthesis. The authors suggest that this method could be useful for studying corneal development and disease. These conclusions are based on the observed structural and mechanical differences between curved and flat tissues.