Optical UVA biosensor platform for high-throughput testing of UV blockers

Area of Science:

• Biotechnology
• Photobiology
• Biomedical Engineering

Background:

• Ultraviolet (UV) radiation poses significant public health risks, including skin cancer and premature aging.
• Current sunscreen evaluation methods like SPF and UVA-PF testing are empirical, ethically challenging, and inconsistent.
• There is a need for reliable, high-throughput methods for assessing UV protection.

Purpose of the Study:

• To develop a novel cell-based biosensor for quantifying UV-A radiation exposure.
• To establish a high-throughput, reproducible, and ethically sound alternative to in vivo sunscreen testing.
• To validate the Assay for UV-A Radiation Assessment (AURA) for detecting UV-A light.

Main Methods:

• Engineered AURA-transgenic human cells expressing a photocleavable PhoCl domain fused to TetR-VP16.
• UV-A exposure (320-400 nm) triggers PhoCl cleavage, releasing TetR-VP16.
• Nuclear translocation of TetR-VP16 activates a tetracycline-responsive reporter, generating luminescence.

Main Results:

• The AURA biosensor demonstrated sensitive detection of UV-A light at 365 nm and 395 nm.
• Achieved up to 100-fold induction in reporter activity upon UV-A exposure.
• The system showed high precision and reproducibility in response to UV-A.

Conclusions:

• AURA provides a powerful platform for high-throughput screening of UV-blocking agents.
• This cell-based assay offers a transformative, ethical alternative to current in vivo UVA-PF assessment methods.
• AURA enhances sunscreen development through accurate, reproducible, and ethically advantageous testing.