Replacing the Draize eye test: Impedance spectroscopy as a 3R method to discriminate between all GHS categories for...

Area of Science:

• Toxicology
• Biotechnology
• Ophthalmology

Background:

• The Draize eye test, an animal-based procedure, faces criticism for poor human transferability and animal welfare concerns.
• Alternative animal-free methods are sought to replace established toxicity tests like the Draize test.
• Current alternatives struggle to identify all categories of eye irritation.

Purpose of the Study:

• To develop a novel in vitro test for identifying all categories of eye irritation.
• To replace the invasive Draize eye test with a reliable, animal-free alternative.
• To improve the accuracy and reproducibility of eye irritation assessments.

Main Methods:

• Utilized organotypic cornea models derived from primary human cornea epithelial cells.
• Integrated an electrical readout system measuring impedance spectroscopy for non-destructive analysis.
• Employed repeated measurements over 7 days and a novel prediction model.

Main Results:

• Primary human cornea epithelial cell models showed advantageous native marker expression compared to epidermal keratinocyte models.
• Impedance spectroscopy increased test system sensitivity for eye irritation detection.
• Achieved 78% accuracy and 88.9% reproducibility in identifying all three eye irritation categories.

Conclusions:

• The developed in vitro test successfully identifies all Globally Harmonized System categories of eye irritation.
• This animal-free approach offers a promising alternative to the Draize eye test, aligning with the 3R principles.
• The method has the potential to significantly advance ethical and accurate risk assessment in toxicology.