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bioRxiv · 10.64898/2026.03.10.709798

Iota-carrageenan protects the ocular surface from desiccation-induced cell death and tissue damage in vitro and ex vivo

Roch-Nakowitsch, S.·Russo, A.·Koller, C.·Dolischka, A.·Koenig-Schuster, M.·Dellago, H.·Prieschl-Grassauer, E.
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Abstract

Iota-carrageenan is a natural polymer with moisturizing, mucoadhesive and shear-thinning properties. In this study, we aimed to evaluate the protective effects of iota-carrageenan on ocular surface against dehydration, to demonstrate its suitability for the use in lubricant eye drops. We utilized a human epithelial corneal cell culture model to test if pre-incubation with iota-carrageenan solution could protect cells from desiccation-induced cell death, to compare its effect with other natural polymers commonly used in artificial tear products, and to determine the optimal iota-carrageenan concentration. An ex vivo porcine eye model was established to confirm the protective effect of iota-carrageenan against dehydration on ocular tissue. Pre-incubation with 1.2 mg/ml iota-carrageenan increased the survival half-life of human corneal epithelial cells upon dehydration by three-fold; the effect was in the same range as observed for large molecular weight hyaluronic acid, and superior to all other tested natural polymers. The highest tested concentration of iota- carrageenan, 1.6 mg/ml, extended the cellular survival half-life by eight-fold while maintaining healthy cellular morphology. Repeated ex vivo instillation of an iota-carrageenan-based ophthalmic formulation into porcine eyes significantly protected the ocular surface from desiccation-induced corneal damage, as shown by corneal fluorescein staining These data suggest that Iota-carrageenan effectively moisturizes and protects the ocular surface, supporting its potential as a promising novel ingredient for eye drops in the management of dry eye disease.

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Roch-Nakowitsch, S., Russo, A., Koller, C., Dolischka, A., Koenig-Schuster, M., Dellago, H., Prieschl-Grassauer, E.. 2026-03-12. Iota-carrageenan protects the ocular surface from desiccation-induced cell death and tissue damage in vitro and ex vivo. https://doi.org/10.64898/2026.03.10.709798

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