Advances in Continuous Microfluidics-Based Technologies for the Study of HIV Infection

Abstract

HIV-1 is the causative agent of acquired immunodeficiency syndrome (AIDS). It affects millions of people worldwide and the pandemic persists despite the implementation of highly active antiretroviral therapy. A wide spectrum of techniques has been implemented in order to diagnose and monitor AIDS progression over the years. Besides the conventional approaches, microfluidics has provided useful methods for monitoring HIV-1 infection. In this review, we introduce continuous microfluidics as well as the fabrication and handling of microfluidic chips. We provide a review of the different applications of continuous microfluidics in AIDS diagnosis and progression and in the basic study of the HIV-1 life cycle.

Microfluidic Devices for HIV Diagnosis and Monitoring at Point-of-Care (POC) Settings

“…Biomolecules are concentrated at the first stage but are then transferred to the second stage and then reconcentrated. This process repeats until the biomolecules reach the final stage, improving the concentration performance [ 107 ]. This method is capable of detecting nucleic acid and proteins at low concentrations in human sera.…”

Optical Quantification by Nanopores of Viruses, Extracellular Vesicles, and Nanoparticles

“…Currently commercially available assays offer noteworthy detection limits, for example 200 DNA copies/mL for quantitative commercial real-time Polymerase Chain Reaction (qPCR)-based assays 1,2 , or 6 − 10 × 10 5 particles/mL for Western Blot/ ELISA assays 3 . In any case, these methods are time-consuming (about 24 hours for ELISA or Western Blot), too specific (ELISA and Western Blot assays can be carried out only if a primary antibody against the protein of interest is available), and sometimes inaccurate (due to off-target effects and saturation of the signal) 4,5 .Therefore, they do not fully respond to the requested specifications in several fields of application such as clinical diagnosis (live monitoring of virus levels in patient samples) and basic research which may focus on different stages of the virus cycle (entry into the cell, reverse transcription, release of new virions,...). To meet demand several microfluidic and single molecule based quantification techniques are now under development [5][6][7] .…”

“…In any case, these methods are time-consuming (about 24 h for ELISA or Western Blot), too specific (ELISA and Western Blot assays can be carried out only if a primary antibody against the protein of interest is available), and sometimes inaccurate (due to off-target effects and saturation of the signal). , Therefore, they do not fully respond to the requested specifications in several fields of application such as clinical diagnosis (live monitoring of virus levels in patient samples) and basic research which may focus on different stages of the virus cycle (entry into the cell, reverse transcription, release of new virions, and so forth). To meet demand, several microfluidic and single molecule-based quantification techniques are now under development. − For instance, commercial Nanoparticle Tracking Analysis (NTA) can be used to determine concentration and size distribution of fluorescent viral particles. NTA offers a limit of detection (LOD) of 10 6 particles/mL and a manipulation time of a few hours. − Interferometric light microscopy can also be used to quantify viruses while measuring scattered signal and Brownian motion but the LOD is elevated (10 8 –10 10 particles/mL) …”

Viro-fluidics: Real-time analysis of virus production kinetics at the single-cell level

“…In the field of the human immunodeficiency virus type 1 (HIV-1), responsible for the acquired immunodeficiency syndrome pandemic, the microfluidics has been mainly used for the diagnostics of acquired immunodeficiency syndrome with the detection of viral nucleic acids or anti-HIV antibodies ( 13 ), and for high-throughput screening of therapeutic tests ( 14 , 15 , 16 ) or transcriptome analysis ( 17 , 18 , 19 ) (for a review see ( 20 )). Here, we implemented a “viro-fluidics” approach that combines continuous microfluidics using chips fabricated from polydimethylsiloxane (PDMS) and virology under cell culture conditions.…”