Integrated high-throughput drug screening microfluidic system for comprehensive ocular toxicity assessment

Area of Science:

• Ophthalmology
• Toxicology
• Biomedical Engineering

Background:

• Traditional toxicological evaluations of eye drop preservatives face limitations.
• Preservatives in eye drops can cause toxicity to ocular surface cells.

Purpose of the Study:

• To develop and validate a microfluidic system for precise control and evaluation of preservative toxicity.
• To compare the toxicological effects of preservatives on corneal cells from healthy versus dry eyes.

Main Methods:

• A microfluidic device with a gradient concentration generator, microvalves, and micropumps was designed.
• An Arduino board automated the system for precise preservative dosage control.
• Human corneal epithelial cells were exposed to eight concentrations of preservatives in quadruplicate.
• The system simulated healthy and dry eye conditions to assess benzalkonium chloride toxicity.

Main Results:

• The microfluidic system enabled simultaneous toxicological evaluation of multiple preservative concentrations.
• A significant, approximately twofold difference in IC50 values was observed between healthy and dry eyes.
• Benzalkonium chloride showed IC50 values of 0.0033% for healthy eyes and 0.0017% for dry eyes.
• Exposure time was identified as a critical factor influencing preservative cytotoxicity.

Conclusions:

• The automated microfluidic system offers an innovative alternative for eye drop preservative toxicity testing.
• The study highlights differential preservative toxicity in dry eye conditions, emphasizing the need for tailored formulations.
• The pinch-to-zoom feature integration offers novel interaction possibilities for microfluidic eye research.