High-Performance Passive Plasma Separation on OSTE Pillar Forest.

Zhiqing Xiao,Chia-Lin Sheu,Sihan Dai,Yuqian Yang,Weijin Guo,Lexin Sun,Zitao Feng,Xingwei Zhang,Hao Yang

doi:10.3390/bios11100355

Abstract

Plasma separation is of high interest for lateral flow tests using whole blood as sample liquids. Here, we built a passive microfluidic device for plasma separation with high performance. This device was made by blood filtration membrane and off-stoichiometry thiol–ene (OSTE) pillar forest. OSTE pillar forest was fabricated by double replica moldings of a laser-cut polymethylmethacrylate (PMMA) mold, which has a uniform microstructure. This device utilized a filtration membrane to separate plasma from whole blood samples and used hydrophilic OSTE pillar forest as the capillary pump to propel the plasma. The device can be used to separate blood plasma with high purity for later use in lateral flow tests. The device can process 45 L of whole blood in 72 s and achieves a plasma separation yield as high as 60.0%. The protein recovery rate of separated plasma is 85.5%, which is on par with state-of-the-art technologies. This device can be further developed into lateral flow tests for biomarker detection in whole blood.

Highlights

Pillar forest substrate); the red arrow indicates the direction of blood flow. (c) A real device. (d) The whole process of plasma separation on a device: we loaded 45 μL of whole blood on the center of the filtration membrane; we found that plasma appeared in the region under the hydrophilic tape
We characterized the flow behavior and capillary flow rate of water on these two different substrates and chose the off-stoichiometry thiol–ene (OSTE) pillar forest fabricated with p = 350 μm as the substrate material, which can provide a bigger volume capacity at 6.32 μL/cm2
All of the steps including pattern design, PDMS molding, OSTE molding, laser cutting, and hydrophilic treatments can be performed in less than three hours, which can benefit the iteration of device design

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Blood contains many biomarkers that are related to the health conditions of human body, from indexes of nutrients (such as glucose and vitamin) to cancer markers (such as prostate-specific antigen) [1,2,3]. Many point-of-care diagnostic platforms use whole blood as sample liquids for testing. Plasma separation is needed for many tests to avoid the disturbance of hemoglobin from red blood cells. Active and passive methods are used to filter blood cells from whole blood using microfluidic systems [4]

Methods

Results

Conclusion