{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T15:51:55Z","timestamp":1777909915869,"version":"3.51.4"},"reference-count":39,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2018,8,2]],"date-time":"2018-08-02T00:00:00Z","timestamp":1533168000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BPD\/108889\/2015"],"award-info":[{"award-number":["SFRH\/BPD\/108889\/2015"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["project IC&DT \u2013 AAC n.\u00ba 02\/SAICT\/2017 - n.\u00ba 28178 \u2013 MalariaChip"],"award-info":[{"award-number":["project IC&DT \u2013 AAC n.\u00ba 02\/SAICT\/2017 - n.\u00ba 28178 \u2013 MalariaChip"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Norte Portugal Regional Operational Programme (NORTE 2020)","award":["AAC n.\u00ba 02\/SAICT\/2017 - n.\u00ba 28178 \u2013 MalariaChip"],"award-info":[{"award-number":["AAC n.\u00ba 02\/SAICT\/2017 - n.\u00ba 28178 \u2013 MalariaChip"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>Malaria is one of the leading causes of death in underdeveloped regions. Thus, the development of rapid, efficient, and competitive diagnostic techniques is essential. This work reports a study of the deformability and velocity assessment of healthy and artificially impaired red blood cells (RBCs), with the purpose of potentially mimicking malaria effects, in narrow polydimethylsiloxane microchannels. To obtain impaired RBCs, their properties were modified by adding, to the RBCs, different concentrations of glucose, glutaraldehyde, or diamide, in order to increase the cells\u2019 rigidity. The effects of the RBCs\u2019 artificial stiffening were evaluated by combining image analysis techniques with microchannels with a contraction width of 8 \u00b5m, making it possible to measure the cells\u2019 deformability and velocity of both healthy and modified RBCs. The results showed that healthy RBCs naturally deform when they cross the contractions and rapidly recover their original shape. In contrast, for the modified samples with high concentration of chemicals, the same did not occur. Additionally, for all the tested modification methods, the results have shown a decrease in the RBCs\u2019 deformability and velocity as the cells\u2019 rigidity increases, when compared to the behavior of healthy RBCs samples. These results show the ability of the image analysis tools combined with microchannel contractions to obtain crucial information on the pathological blood phenomena in microcirculation. Particularly, it was possible to measure the deformability of the RBCs and their velocity, resulting in a velocity\/deformability relation in the microchannel. This correlation shows great potential to relate the RBCs\u2019 behavior with the various stages of malaria, helping to establish the development of new diagnostic systems towards point-of-care devices.<\/jats:p>","DOI":"10.3390\/mi9080384","type":"journal-article","created":{"date-parts":[[2018,8,3]],"date-time":"2018-08-03T03:03:15Z","timestamp":1533265395000},"page":"384","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":44,"title":["Assessment of the Deformability and Velocity of Healthy and Artificially Impaired Red Blood Cells in Narrow Polydimethylsiloxane (PDMS) Microchannels"],"prefix":"10.3390","volume":"9","author":[{"given":"Liliana Vilas","family":"Boas","sequence":"first","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Instituto Polit\u00e9cnico de Bragan\u00e7a, ESTiG, C. Sta. Apol\u00f3nia, 5300-253 Bragan\u00e7a, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9041-2188","authenticated-orcid":false,"given":"Vera","family":"Faustino","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"MEtRICs, DEM, University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3428-637X","authenticated-orcid":false,"given":"Rui","family":"Lima","sequence":"additional","affiliation":[{"name":"MEtRICs, DEM, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"CEFT, University of Porto, 4000-008 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1830-0525","authenticated-orcid":false,"given":"Jo\u00e3o M\u00e1rio","family":"Miranda","sequence":"additional","affiliation":[{"name":"CEFT, University of Porto, 4000-008 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2460-0556","authenticated-orcid":false,"given":"Gra\u00e7a","family":"Minas","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"given":"Carla Sofia Veiga","family":"Fernandes","sequence":"additional","affiliation":[{"name":"Instituto Polit\u00e9cnico de Bragan\u00e7a, ESTiG, C. Sta. Apol\u00f3nia, 5300-253 Bragan\u00e7a, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8962-0710","authenticated-orcid":false,"given":"Susana Oliveira","family":"Catarino","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2018,8,2]]},"reference":[{"key":"ref_1","unstructured":"WHO (2016). Malaria World Report, World Health Organization."},{"key":"ref_2","unstructured":"WHO (2017). Malaria Rapid Diagnostic Test Performance: Results of WHO Product Testing of Malaria RDTs, World Health Organization."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"119","DOI":"10.4269\/ajtmh.2007.77.119","article-title":"A review of malaria diagnostic tools: Microscopy and rapid diagnostic test (RDT)","volume":"77","author":"Wongsrichanalai","year":"2007","journal-title":"Am. J. Trop. Med. Hyg."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Lucchi, N., Ljolje, D., Silva-Flannery, L., and Udhayakumar, V. (2016). Use of malachite green-loop mediated isothermal amplification for detection of Plasmodium spp. parasites. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0151437"},{"key":"ref_5","unstructured":"(2018, March 01). QuantuMDx. Available online: http:\/\/quantumdx.com\/applications\/malaria."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Saha, R., Karmakar, S., and Roy, M. (2012). Computational investigation on the photoacoustics of malaria infected red blood cells. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0051774"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"382","DOI":"10.1557\/mrs2010.571","article-title":"Shape and biomechanical characteristics of human red blood cells in health and disease","volume":"35","author":"Dao","year":"2010","journal-title":"MRS Bull."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1086\/596048","article-title":"High deformability of Plasmodium vivax-infected red blood cells under microfluidic conditions","volume":"199","author":"Handayani","year":"2009","journal-title":"J. Infectious Dis."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"14618","DOI":"10.1073\/pnas.2433968100","article-title":"A microfluidic model for single-cell capillary obstruction by Plasmodium falciparum-infected erythrocytes","volume":"100","author":"Shelby","year":"2003","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1016\/S1873-9784(96)80011-8","article-title":"Hemodynamics of vascular prostheses","volume":"Volume 1","author":"How","year":"1996","journal-title":"Advances in Hemodynamics and Hemorheology"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"051501","DOI":"10.1063\/1.4895755","article-title":"Biomechanical properties of red blood cells in health and disease towards microfluidics","volume":"8","author":"Tomaiuolo","year":"2014","journal-title":"Biomicrofluidics"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/S0076-6879(89)73004-4","article-title":"Ektacytometry of red blood cells","volume":"173","author":"Johnson","year":"1989","journal-title":"Methods Enzymol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1837","DOI":"10.1016\/j.actamat.2003.12.028","article-title":"Large deformation of living cells using laser traps","volume":"52","author":"Lim","year":"2004","journal-title":"Acta Mater."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"810","DOI":"10.1038\/nature01935","article-title":"A revolution in optical manipulation","volume":"424","author":"Grier","year":"2003","journal-title":"Nature"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/S0021-9290(99)00175-X","article-title":"Micropipette aspiration of living cells","volume":"33","author":"Hochmuth","year":"2000","journal-title":"J. Biomech."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1007\/s10544-015-0014-2","article-title":"A simple microfluidic device for the deformability assessment of blood cells in a continuous flow","volume":"17","author":"Rodrigues","year":"2015","journal-title":"Biomed. Microdevices"},{"key":"ref_17","first-page":"747","article-title":"Microscopic investigation of erythrocyte deformation dynamics","volume":"43","author":"Zhao","year":"2006","journal-title":"Biorheology"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"054110","DOI":"10.1063\/1.4820414","article-title":"Human red blood cell behavior under homogeneous extensional flow in a hyperbolic shaped microchannel","volume":"7","author":"Yaginuma","year":"2013","journal-title":"Biomicrofluidics"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1007\/s13206-014-8107-1","article-title":"Extensional flow-based microfluidic device: Deformability assessment of red blood cells in contact with tumor cells","volume":"8","author":"Faustino","year":"2014","journal-title":"BioChip J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1021","DOI":"10.1007\/s10544-009-9319-3","article-title":"Extensional flow-based assessment of red blood cell deformability using hyperbolic converging microchannel","volume":"11","author":"Lee","year":"2009","journal-title":"Biomed. Microdevices"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Bento, D., Rodrigues, R.O., Faustino, V., Pinho, D., Fernandes, C.S., Pereira, A.I., Garcia, V., Miranda, J.M., and Lima, R. (2018). Deformation of red blood cells, air bubbles, and droplets in microfluidic devices: Flow visualizations and measurements. Micromachines, 9.","DOI":"10.3390\/mi9040151"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2605","DOI":"10.1039\/c003873c","article-title":"Deformability based cell margination\u2014A simple microfluidic design for malaria-infected erythrocyte separation","volume":"10","author":"Hou","year":"2010","journal-title":"Lab Chip"},{"key":"ref_23","unstructured":"Passos, A., Sherwood, J., Agrawal, R., Pavesio, C., and Balabani, S. (2016, January 11\u201314). The effect of RBC stiffness on microhaemodynamics. Proceedings of the 5th Micro and Nano Flows Conference, Milan, Italy."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1146\/annurev.ph.49.030187.001141","article-title":"Red blood cell deformability and its relevance to blood flow","volume":"49","author":"Chien","year":"1987","journal-title":"Ann. Rev. Physiol."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Tavares, J., and Natal Jorge, R. (2018). Imaging of healthy and malaria-mimicked red blood cells in polydimethylsiloxane microchannels for determination of cells deformability and flow velocity. VipIMAGE\u2014ECCOMAS 2017. Lecture Notes in Comp. Vision and Biomechanics, Springer.","DOI":"10.1007\/978-3-319-68195-5"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Kaneko, M., Ishida, T., Tsai, C.D., Ito, H., Chimura, M., Taniguchi, T., Ohtani, T., and Sakata, Y. (2017, January 6\u20139). On-Chip RBC Deformability Checker Embedded with Vision Analyzer. Proceedings of the 2015 IEEE International Conference on Mechatronics and Automation, Takamatsu, Japan.","DOI":"10.1109\/ICMA.2017.8016126"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Tsai, C.D., Tanaka, J., Kaneko, M., Horade, M., Ito, H., Taniguchi, T., Ohtani, T., and Sakata, Y. (2016). An On-Chip RBC Deformability Checker Significantly Improves Velocity-Deformation Correlation. Micromachines, 7.","DOI":"10.3390\/mi7100176"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1016\/j.mvr.2006.02.006","article-title":"Measurement of RBC deformation and velocity in capillaries in vivo","volume":"71","author":"Jeong","year":"2006","journal-title":"Microvasc. Res."},{"key":"ref_29","first-page":"WMC004375","article-title":"Red Blood Cells deformability index assessment in a hyperbolic microchannel: The diamide and glutaraldehyde effect","volume":"4","author":"Rodrigues","year":"2013","journal-title":"Webmed Cent. Biomed. Eng."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.mvr.2010.03.008","article-title":"The dynamic behavior of chemically \u201cstiffened\u201d red blood cells in microchannel flows","volume":"80","author":"Forsyth","year":"2010","journal-title":"Microvasc. Res."},{"key":"ref_31","first-page":"273","article-title":"Influence of hyperglycemia on aggregation, deformability and shape parameters of erythrocytes","volume":"31","author":"Babu","year":"2004","journal-title":"Clin. Hemorheol. Microcirc."},{"key":"ref_32","first-page":"153","article-title":"Rheological characteristics of erythrocytes incubated in glucose media","volume":"38","author":"Shin","year":"2008","journal-title":"Clin. Hemorheol. Microcirc."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"738","DOI":"10.3390\/mi5030738","article-title":"Optimized SU-8 Processing for Low-Cost Microstructures Fabrication without Cleanroom Facilities","volume":"5","author":"Pinto","year":"2014","journal-title":"Micromachines"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2280","DOI":"10.1016\/j.jbiomech.2015.11.031","article-title":"Biomedical microfluidic devices by using low-cost fabrication techniques: A review","volume":"49","author":"Faustino","year":"2016","journal-title":"J. Biomech."},{"key":"ref_35","first-page":"36","article-title":"Image processing with ImageJ","volume":"11","author":"Abramoff","year":"2004","journal-title":"Biophotonics Int."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"e30","DOI":"10.5334\/jors.bl","article-title":"PIVlab\u2014Towards User-friendly, Affordable and Accurate Digital Particle Image Velocimetry in MATLAB","volume":"2","author":"Thielicke","year":"2014","journal-title":"J. Open Res. Softw."},{"key":"ref_37","unstructured":"Thielicke, W., and Stamhuis, E.J. (2017, July 01). PIVlab\u2014Time-Resolved Digital Particle Image Velocimetry Tool for MATLAB. Available online: https:\/\/figshare.com\/articles\/PIVlab_version_1_35\/1092508."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1002\/ajh.23941","article-title":"A biomimetic microfluidic chip to study the circulation and mechanical retention of red blood cells in the spleen","volume":"90","author":"Picot","year":"2015","journal-title":"Am. J. Hematol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1182\/bloodadvances.2017013730","article-title":"Reduced red blood cell deformability in Plasmodium knowlesi malaria","volume":"2","author":"Barber","year":"2018","journal-title":"Blood Adv."}],"container-title":["Micromachines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-666X\/9\/8\/384\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:16:04Z","timestamp":1760195764000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-666X\/9\/8\/384"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,8,2]]},"references-count":39,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2018,8]]}},"alternative-id":["mi9080384"],"URL":"https:\/\/doi.org\/10.3390\/mi9080384","relation":{},"ISSN":["2072-666X"],"issn-type":[{"value":"2072-666X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,8,2]]}}}