{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T17:42:40Z","timestamp":1787766160208,"version":"build-2784847793"},"reference-count":25,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2019,6,18]],"date-time":"2019-06-18T00:00:00Z","timestamp":1560816000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Thrombus formation in hemostasis or thrombotic disease is initiated by the rapid adhesion, activation, and aggregation of circulating platelets in flowing blood. At arterial or pathological shear rates, for example due to vascular stenosis or circulatory support devices, platelets may be exposed to highly pulsatile blood flow, while even under constant flow platelets are exposed to pulsation due to thrombus growth or changes in vessel geometry. The aim of this study is to investigate platelet thrombus formation dynamics within flow conditions consisting of either constant or variable shear. Human platelets in anticoagulated whole blood were exposed ex vivo to collagen type I-coated microchannels subjected to constant shear in straight channels or variable shear gradients using different stenosis geometries (50%, 70%, and 90% by area). Base wall shears between 1800 and 6600 s\u22121, and peak wall shears of 3700 to 29,000 s\u22121 within stenoses were investigated, representing arterial-pathological shear conditions. Computational flow-field simulations and stenosis platelet thrombi total volume, average volume, and surface coverage were analysed. Interestingly, shear gradients dramatically changed platelet thrombi formation compared to constant base shear alone. Such shear gradients extended the range of shear at which thrombi were formed, that is, platelets became hyperthrombotic within shear gradients. Furthermore, individual healthy donors displayed quantifiable differences in extent\/formation of thrombi within shear gradients, with implications for future development and testing of antiplatelet agents. In conclusion, here, we demonstrate a specific contribution of blood flow shear gradients to thrombus formation, and provide a novel platform for platelet functional testing under shear conditions.<\/jats:p>","DOI":"10.3390\/ijms20122967","type":"journal-article","created":{"date-parts":[[2019,6,19]],"date-time":"2019-06-19T02:42:46Z","timestamp":1560912166000},"page":"2967","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Novel Stenotic Microchannels to Study Thrombus Formation in Shear Gradients: Influence of Shear Forces and Human Platelet-Related Factors"],"prefix":"10.3390","volume":"20","author":[{"given":"Mathew","family":"Lui","sequence":"first","affiliation":[{"name":"Department of Mechanical and Aerospace Engineering, Monash University, 3800 Clayton, Australia"},{"name":"Monash Institute of Medical Engineering, Monash University, 3800 Clayton, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9453-9688","authenticated-orcid":false,"given":"Elizabeth E.","family":"Gardiner","sequence":"additional","affiliation":[{"name":"Department of Cancer Biology and Therapeutics, John Curtin School of Medical Research, Australian National University, 2600 Canberra, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jane F.","family":"Arthur","sequence":"additional","affiliation":[{"name":"Australian Centre for Blood Diseases, Monash University, 3004 Melbourne, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isaac","family":"Pinar","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Aerospace Engineering, Monash University, 3800 Clayton, Australia"},{"name":"Monash Institute of Medical Engineering, Monash University, 3800 Clayton, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Woei Ming","family":"Lee","sequence":"additional","affiliation":[{"name":"Research School of Electrical, Energy and Materials Engineering, The Australian National University, 2600 Canberra, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kris","family":"Ryan","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Aerospace Engineering, Monash University, 3800 Clayton, Australia"},{"name":"Monash Institute of Medical Engineering, Monash University, 3800 Clayton, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Josie","family":"Carberry","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Aerospace Engineering, Monash University, 3800 Clayton, Australia"},{"name":"Monash Institute of Medical Engineering, Monash University, 3800 Clayton, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9577-8082","authenticated-orcid":false,"given":"Robert K.","family":"Andrews","sequence":"additional","affiliation":[{"name":"Australian Centre for Blood Diseases, Monash University, 3004 Melbourne, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,6,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4311","DOI":"10.1182\/blood-2011-10-386607","article-title":"Pathological shear triggers shedding of vascular receptors: A novel mechanism for downregulation of platelet glycoprotein (GP)VI in stenosed coronary vessels","volume":"119","author":"Tan","year":"2012","journal-title":"Blood"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Gresele, P., Lopez, J.A., Kleiman, N.S., and Page, C.P. (2017). Platelet adhesion. Platelets in Thrombotic and Non-Thrombotic Disorders, Springer.","DOI":"10.1007\/978-3-319-47462-5"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"566","DOI":"10.1182\/blood-2006-07-028282","article-title":"Identification of a 2-stage platelet aggregation process mediating shear-dependent thrombus formation","volume":"109","author":"Maxwell","year":"2007","journal-title":"Blood"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1038\/nm.1955","article-title":"A shear gradient-dependent platelet aggregation mechanism drives thrombus formation","volume":"15","author":"Nesbitt","year":"2009","journal-title":"Nat. Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2447","DOI":"10.3892\/mmr.2016.4825","article-title":"Effects of different shear rates on the attachment and detachment of platelet thrombi","volume":"13","author":"Shi","year":"2016","journal-title":"Mol. Med. Rep."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"170219","DOI":"10.1098\/rsos.170219","article-title":"A physical description of the adhesion and aggregation of platelets","volume":"4","author":"Chopard","year":"2017","journal-title":"R. Soc. Open Sci."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Koltai, K., Kesmarky, G., Feher, G., Tibold, A., and Toth, K. (2017). Platelet aggregometry testing: Molecular mechanisms, techniques and clinical implications. Int. J. Mol. Sci., 18.","DOI":"10.3390\/ijms18081803"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"457","DOI":"10.1080\/09537104.2016.1268254","article-title":"Microfluidic whole blood testing of platelet response to pharmacological agents","volume":"28","author":"Li","year":"2017","journal-title":"Platelets"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1016\/j.blre.2015.05.002","article-title":"Platelets and physics: How platelets \u201cfeel\u201d and respond to their mechanical microenvironment","volume":"29","author":"Qiu","year":"2015","journal-title":"Blood Rev."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1016\/j.jbiomech.2016.11.019","article-title":"A multiscale biomechanical model of platelets: Correlating with in-vitro results","volume":"50","author":"Zhang","year":"2017","journal-title":"J. Biomech."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.jbiomech.2016.11.016","article-title":"Shear-mediated platelet activation in the free flow: Perspectives on the emerging spectrum of cell mechanobiological mechanisms mediating cardiovascular implant thrombosis","volume":"50","author":"Slepian","year":"2017","journal-title":"J. Biomech."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Pinar, I.P., Arthur, J.F., Andrews, R.K., Gardiner, E.E., Ryan, K., and Carberry, J. (2015). Methods to determine the Lagrangian shear experienced by platelets during thrombus growth. PlosONE, 10.","DOI":"10.1371\/journal.pone.0144860"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.tmrv.2014.03.001","article-title":"Platelet receptor expression and shedding: GPIb-IX-V and GPVI","volume":"28","author":"Gardiner","year":"2014","journal-title":"Transfusion Med. Rev."},{"key":"ref_14","first-page":"3009","article-title":"Platelet adhesion: A game of catch and release","volume":"118","author":"Andrews","year":"2008","journal-title":"J. Clin. Invest."},{"key":"ref_15","first-page":"3195","article-title":"Platelet glycoprotein Ib\u03b1 forms catch bonds with human WT vWF but not with type 2B von Willebrand disease vWF","volume":"118","author":"Yago","year":"2008","journal-title":"J. Clin. Invest."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"716","DOI":"10.1160\/TH04-09-0584","article-title":"Glycoprotein VI is associated with GPIb-IX-V on the membrane of resting and activated platelets","volume":"93","author":"Arthur","year":"2005","journal-title":"Thromb. Haemost."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"9984","DOI":"10.1021\/nn403923h","article-title":"Adhesion maturation of neutrophils on nanoscopically presented platelet glycoprotein Ib\u03b1","volume":"7","author":"Kruss","year":"2013","journal-title":"ACS Nano"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.mvr.2013.05.006","article-title":"Computational study on thrombus formation regulated by platelet glycoprotein and blood flow shear","volume":"89","author":"Kamada","year":"2013","journal-title":"Microvasc. Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1080\/09537104.2016.1235690","article-title":"Basic mechanisms of platelet receptor shedding","volume":"28","author":"Andrews","year":"2017","journal-title":"Platelets"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"692","DOI":"10.1016\/j.thromres.2015.01.030","article-title":"Shear-induced platelet receptor shedding by non-physiological high shear stress with short exposure time: Glycoprotein Ib\u03b1 and glycoprotein VI","volume":"135","author":"Chen","year":"2015","journal-title":"Thromb. Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2535","DOI":"10.1182\/blood-2018-03-742668","article-title":"Mechanisms of receptor shedding in platelets","volume":"132","author":"Montague","year":"2018","journal-title":"Blood"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2253","DOI":"10.1111\/jth.13497","article-title":"Mechanical circulatory support is associated with loss of platelet receptors glycoprotein (GP) Ib\u03b1 and GPVI","volume":"14","author":"Lukito","year":"2016","journal-title":"J. Thromb. Haemost."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1016\/j.healun.2015.12.024","article-title":"Longitudinal changes in haemostatic parameters and reduced pulsatility contribute to non-surgical bleeding in patients with centrifugal continuous flow left ventricular assist devices","volume":"35","author":"Muthiah","year":"2016","journal-title":"J. Heart Lung Transpl."},{"key":"ref_24","unstructured":"Geffen, J.P.V., Brouns, S.L.N., Batista, J., McKinney, H., Kempster, C., Nagy, M., Sivapalaratnam, S., Baaten, C.C.F.M.J., Bourry, N., and Frontini, M. (2018). High-throughput elucidation of thrombus formation reveals sources of platelet function variability. Haematologica."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"043003","DOI":"10.1117\/1.2804279","article-title":"Automated segmentation in confocal images using a density clustering method","volume":"16","author":"Chan","year":"2007","journal-title":"J. Electron Imaging"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/20\/12\/2967\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:59:13Z","timestamp":1760187553000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/20\/12\/2967"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,6,18]]},"references-count":25,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2019,6]]}},"alternative-id":["ijms20122967"],"URL":"https:\/\/doi.org\/10.3390\/ijms20122967","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,6,18]]}}}