Lateral Flow Test (LFT) Detects Cell‐Free MicroRNAs Predictive of Preterm Birth Directly from Human Plasma

Abstract

Despite extensive research toward the development of point‐of‐care nucleic acid tests (POC NATs) for the detection of microRNAs (miRs) from liquid biopsies, major hurdles remain including the strict requirement for extensive off‐chip sample preprocessing. Herein, a nucleic acid lateral flow test (NALFT) is reported on that enables the direct detection of endogenous miRs from as little as 3 μL of plasma without the requirement for any enzyme‐catalyzed target amplification or complex miR extraction steps. This is achieved through integration of a denaturing hydrogel composite material onto the LFT, allowing for near‐instantaneous on‐chip release of miRs from their carriers (extracellular vesicles or transport proteins) prior to detection. This next‐generation LFT is sensitive enough to detect endogenous concentrations of miR‐150‐5p, a predictive biomarker for preterm birth (PTB) found deregulated in maternal blood from as early as 12th week of pregnancy. Herein, a key step is represented toward a first bedside test for risk‐stratification during pregnancy by predicting true outcome at a very early stage. More generally, the universal and versatile nature of this novel sample preprocessing platform can further improve the robustness of existing NALFTs and facilitate their application at the POC.

Extended functionalities of paper-based analytical devices using hydrogels for biomedical applications

“…Lastly, the complex combination continued to flow down to peptide nucleic acid (PNA-2) for detection. This method allowed for direct detection of endogenous miRs from as little as 3 µl of plasma using a nucleic acid lateral flow test, eliminating the need for enzyme-catalyzed target amplification or difficult miR extraction processes [39].…”

“…At the test line, where the OTR is conducted, PNA-2 captures the hybridized complex that was created between miR and PNA-1 after it has flowed down the LFA. Reproduced from [39]. CC BY 4.0.…”

“…Both applications combined the hydrogel with paper-based electrophoresis devices for better separation of the biomolecule. In addition, Petrou et al [39] also use the hydrogel as biomolecules separation in LFAs platform using automated on-chip sample processing. Lastly, a hydrogel incorporated on a paper substrate was developed by the Whiteside group to create a 3D scaffold for the cell culture [40].…”

Lateral Flow Assay: A Summary of Recent Progress for Improving Assay Performance

“…The results are often expressed as the analyte concentration level in a sample into high (+++), medium (++), low (+), and very low or absence (−) based on the color intensity of the test line. Petrou et al [ 14 ] developed an LFA test strip integrated with automated sample processing for semi-quantitative analyses of microRNA-150-5p from human plasma exosome, a predictive biomarker for preterm birth (PTB). Peptide nucleic acid (PNA) probes were used to determine microRNA quantitatively via oligonucleotide-templated reaction (OTR).…”