From injury to recovery: investigating wound healing in a 3D tissue-engineered cornea equivalent

The semi-automatic generation of a multilayer cornea model was to study the process of wound healing and the influence of substances modulating wound healing. We generated in vitro corneal human tissues including epithelium and a semi automatedly produced stroma equivalent based on a hydrogel matrix. The maturation was evaluated using impedance spectroscopy, histology and immunofluorescence over 21 days. Inflicting corneal wounds by clinical excimer laser, injury was observed under treated with gentamicin and non-treated for 14 days by histology and optical coherence tomography (OCT). The semi-automated system produced a standardized corneal stroma equivalent that allowed reproducible growth of a multilayered epithelium. The histology and marker expression were comparable to human cornea. Histology confirmed epithelial wound closure 10 days after laser wounding. The wound ratio at day 3, 7, 10 was continuously increasing, day 14 indicating no significant difference to unwounded models. Gentamicin, a standard antibiotic eye drop, displayed reduced closure. In conclusion, the 3D cornea tissue model is recapitulating the human cornea and can be used as a valuable in vitro model for studying wound healing. A robust method to use the hydrogel as biocompatible material is needed. Non-destructive impedance spectroscopy and OCT allow online monitoring of the wound closure.