Colorimetric Detection of Azidothymidine Using an Alkyne-Modified Dextran Substrate

Area of Science:

• Biomedical Diagnostics
• Chemical Assays
• Public Health

Background:

• Adherence to highly active antiretroviral therapy (HAART) is crucial for effective HIV treatment, especially in resource-limited settings.
• Current adherence monitoring methods are often subjective, expensive, or require specialized training.
• Non-adherence leads to treatment failure, increased transmission rates, and higher healthcare costs.

Purpose of the Study:

• To develop a novel, point-of-care assay for directly measuring HAART drug adherence.
• To provide a simple, colorimetric method for detecting specific HAART drugs in patient urine.
• To offer a viable alternative to existing adherence monitoring techniques in resource-limited environments.

Main Methods:

• Development of a dipstick-based assay utilizing azide-alkyne click chemistry.
• Synthesis and characterization of an alkyne-modified dextran for colorimetric detection.
• Testing the assay's specificity and sensitivity for azidothymidine in urine samples.

Main Results:

• The assay successfully detected azidothymidine, an azide-containing HAART drug, in urine samples.
• The assay demonstrated specificity for azide-containing molecules not naturally found in urine.
• Sensitivity was achieved at physiologically relevant concentrations as low as 750 uM.

Conclusions:

• A novel dipstick assay provides a direct, point-of-care method for monitoring HAART adherence.
• The assay is specific, sensitive, and suitable for resource-limited settings.
• This technology offers a cost-effective and accessible alternative for HIV treatment monitoring.