TOWARDS AUTONOMOUS MEASUREMENT OF ANTIRETROVIRAL DRUGS WITH 3D-PRINTED MICROFLUIDICS

Background: Subtherapeutic drug levels can lead to the failure of Human Immunodeficiency Virus (HIV) treatment and prevention regimens [1, 2].Gold-standard HIV drug level monitoring techniques-such as liquid chromatography tandem mass spectrometry (MS)-require bulky and expensive instruments that are not widely accessible at the point-of-need.We previously developed the REverSe TRanscrIptase Chain Termination (RESTRICT) enzymatic assay to rapidly and inexpensively measure tenofovir diphosphate (TFV-DP), a nucleotide analog used in most oral HIV treatment and prevention regimens [2, 3].However, RESTRICT currently requires trained operators to perform multiple time-sensitive liquid-handling steps.To reduce user intervention and minimize the need for external laboratory equipment, we created a 3D-printed capillaric microfluidic chip to automate the incubation and intercalating dye incorporation steps of RESTRICT.