Despite lacking human-relevance, animal models are often used in eye disease research due to their accessibility and the complexity of eye anatomy. NAVS is helping to fund some human-cell based alternatives for this purpose, and we are excited to share with you some additional innovative in vitro eye models that are being created at the University of Pennsylvania.
Recognizing that current preclinical eye models do not accurately mimic human biological responses and are expensive and time-consuming, researchers in Dongeun Huh’s lab set out to create a complex, in vitro alternative— an “eye-on-a-chip” microdevice that models the surface of the human eye. They recently published their findings in Nature Medicine.
The researchers used a reverse-engineering strategy, combining human cells with “a synthetically created yet physiological culture environment to replicate the key biological features of the ocular surface at the cellular, tissue and whole organ levels.” To do this, they cultured human cells on scaffolds to create a curved surface designed to mimic the cornea, and created an artificial eyelid connected to a motor to simulate blinking. The model also contained “tear fluid,” enabling the ocular surface to stay hydrated.
The model will help scientists study the interface between the eye and the environment and can be used for many purposes, including the testing of eye medicines, consumer products, environmental materials, surgical procedures and biomedical devices like contact lenses.
The researchers even showed that the eye-on-a-chip microdevice can be used to study eye conditions such as dry eye disease (DED). They were able to test potential therapeutics on the model which “made it possible to generate in vitro data directly comparable to clinical findings, greatly facilitating the process of validating the physiological and clinical relevance of the model.” This is important, given that several dry-eye therapies validated by preclinical mouse studies have failed in human clinical trials because of “interspecies differences” and failure of the animals “to simulate the underlying pathophysiology of human DED.”
We commend these researchers for the contributions they have made toward the generation of a cost-effective, predictive and ethical alternative to animal experimentation. We will keep you posted on further developments with this model and others which seek to reduce reliance on animal models.