The capability to analyze blood plasma proteome is very useful to disease diagnosis and therapeutic monitoring [1], but the time between plasma separation from blood and its analysis is critical for consistent results [2]. The latest advances in nanotechnology, biochemistry and material science combined with the development of affordable miniaturized diagnostic devices enable to develop simple and fast methods to detect and tackle infectious diseases. Recent advances in desktop stereolithographic (SLA) 3D printers enable low-cost rapid prototyping of microfluidic structures reducing the complexity of the design and decreasing the amount of external support equipment required [3]. Previously, plasma separation inside microfluidic devices has been demonstrated using a two-phase plug [4],[5], highly confined microchannels [6], and a stand-alone self-powered integrated microfluidic system [3]. Building on these recent technologies we have developed a microfluidic system to split the plasma from the whole blood instantly.
In this work, we have optimized a 3D-printed structure for the separation of plasma from blood based on blood capillary flow into micro channels. Structures were designed to be printed using a standard stereolithographic 3D printer (Miicraft 3D, Hsinchu, Taiwan, 450 ppi). Samples were printed with a layer thickness of 50 µm using UV curable acrylate (Clear Resin BV-003, Young Optics Inc., Hsinchu, Taiwan). After printing, the samples were washed with ethanol to remove uncured resin, dried with nitrogen and post-cured using an integrated UV-Lamp (18W UVA Lamp). Contact angle measurements (68.3 ±2.1o for water) revealed no difference in the surface energy using different post-curing process times ranging from 0 – 1200 s. We investigated the influence of surface treatment with oxygen plasma on the blood flow velocity. The design of the microfluidic geometry was optimized for on-chip plasma separation. After plasma separation, the sample can be directed on-chip for analysis with integrated electrochemical or optical sensors.
In summary, we have developed a standalone 3D-printed microfluidic system for passive, i.e. without pumps or vacuum, extraction of plasma from small amounts of whole blood.
Capes-PDSE (Process 10585-14-1); Embrapa; UFSCar; Forschungszentrum Jülich
References:
[1] The Human Plasma Proteome, Molecular & Cellular Proteomics 1.11, 2002 by The American Society for Biochemistry and Molecular Biology, Inc.
[2] Sen-Yung Hsieh, Ren-Kung Chen, Yi-Hsin Pan and Hai-Lun Lee; Proteomics, 2006, 6, 3189–3198.
[3] Ivan K. Dimov, Lourdes Basabe-Desmonts, Jose L. Garcia-Cordero, Benjamin M. Ross, Antonio J. Ricco and Luke P. Lee; Lab Chip, 2011, 11, 845–850.
[4] Sung Yang, Akif Undar and Jeffrey D. Zahn; Lab Chip, 2006, 6, 871–880.
[5] Meng Sun, Zeina S. Khan and Siva A. Vanapalli; Lab Chip, 2012, 12, 5225–5230.
[6] Guillermo R. L´azaro, Aurora Hernandez-Machadoa and Ignacio Pagonabarraga; Soft Matter, 2014, 10, 7195.