Name: microfluidic flow chambers using reconstituted blood to model hemostasis and platelet transfusion in vitro
Uploaded: 2016-03-19T14:00:00.000+00:00
Duration: 10 min 25 s
Description: Watch this Scientific Journal Video about Microfluidic Flow Chambers Using Reconstituted Blood to Model Hemostasis and Platelet Transfusion In Vitro at JoVE.com

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Bu protokol, insan numuneler üzerinde araştırmalar için kurumsal etik kuralları takip ve bilgilendirilmiş onam ilgili tüm vericilerden elde edildi. Burada tarif edilen deneyler için onay Antwerp Üniversitesi Hastanesi kurumsal inceleme kurulu elde edilmiştir. Not: belirtilmediği sürece Sıcaklık göstergeleri, her zaman oda sıcaklığı vardır. 1. Hazırlık Akış Odası Kurulumu <ol><li> Hazırlama Lanes, Boru ve iğneler <ol><li> Vorteks kuvvetli bir şekilde kollajen süspansiyonu ve 50 ug / ml&#39;lik bir nihai konsantrasyona kadar sağlayıcı tarafından sağlanan izotonik glikoz çözeltisinde 1/20 seyreltin. Not: Biz esas olarak tip I fibriller oluşur, at tendon kollajen kullanın. At kollajen tip I sık sık &quot;Horm&quot; kolajen olarak adlandırılır ve tarihsel yanı sıra biyolojik nedenlerle hem tahlil 9 bu tür altın standardı mesafesindedir. İnsan tip III kollajen de kullanılabilir, ancak inci edilebilire daha az kat fibrillerinde ve trombosit cevabı kadar güçlü değildir. Diğer kaplama yüzeyleri de, örneğin von Willebrand Faktörü (vWF), fibrinojen, fibronektin, laminin, vitronektin, trombospondin-1 ya da bu 16 kombinasyonları için, kullanılabilir. </li><li> sağlayıcının kaptan yeni bir atılabilir Bioçip alın. Burada kullanılan bioçipler boyutları mm 3 0.4 W x 0.1 H x 20L vardır. </li><li> Pipetleyin çıkış olarak çip ve işaretinin bir ucunda mikroakışkan Biochip kulvar (lar) 0.8 ul. şerit 1.1.1 hazırlanan kaplama çözeltisi içeren kollajen ile 5 / 6th dolu olduğundan emin olun. hiç hava kabarcığı olmadığından emin olun. Not: Kanallar kısmen (tartışma) kanalı girişinde kollajen liflerinin birikmesini önlemek için kaplanır. </li><li> nemlendirilmiş ve kapalı bir kap içinde 4 saat veya gece boyunca 4 ° C&#39;de inkübe edin. </li><li> / H) inek serumu albumin (w bloke edici tampon (% 1.0 pipetleme kaplanmış kanallarını blokediğer ucu ile gösterirken, d,% 0.1 (a / h) glukoz, 10 mM 4- (2-hidroksietil) -1-piperazinetansülfonik asit (HEPES) tamponlu tuzlu su (hacim / hacim) NaCl, pH 7.4% 0.9 (HBA) &#39;de giriş olarak. şerit tamamen hava kabarcıkları kaçınarak engelleme tamponu ile dolu olduğundan emin olun. </li><li> eşit uzunlukta (12 cm) hortumu kesilir. kulvar başına birini kullanın ve bir iğne ile her tüp bağlayın. Örneğin, iki nüsha halinde çalışan iki koşulları karşılaştıran bir deney, dört boru uzanıyor ve dört pim hazırlanacak gerektirecektir. </li><li> bir şırınga ve bir 26 G iğne ya da eşlik eden bağlayıcıları kullanılarak saf su ile boru durulayın. </li><li> bloklama tamponu ile boru doyurabilecek. 1 saat arasında, en az bir kapalı ve nemli bir kap içinde depolayın. </li></ol></li><li> Pompa ve Manifold hazırlama <ol><li> hava kabarcıklarını çıkarmak, pompayı durulayın ve damıtılmış su ile manifoldu. </li><li> çıkışında sabit 10 ul ucunu kullanarak biyoçip şeritli (ler) engelleme tampon aspire. yüzeyini temizleyinhassas silip toz ve denatüre alkol ile Biochip baskılar ve tozunu alın. </li><li> otomatik mikroskop sahnede Bioçip sabitleyin. Birden fazla şeritli bir seferde aynı anda kullanılırsa, biyoçip çıkışına sekiz şerit manifoldu ayırıcı bağlanır. Not: Sekiz şeritli manifoldu ayırıcı donanım parçasıdır (Şekil S1) pompa ve Biochip bağlı. Bu Bioçip veya operatör tanımlı eden yazılım olabilir şerit kombinasyonuna tüm (sekiz) şerit çalışmasını sağlar. </li><li> biochipin girişinde bunları düzeltmek için tüp işaretçilerine kullanın. HBS ile doldurulmuş 1.5 ml konik biçiminde bir test tüpü içinde (PIN olmadan) hortumun diğer ucu yerleştirin. kalan tampon engelleme ve kötü kolajen yapışmış kaldırmak amacıyla, tüm boru ve 1 ml HBS pompa kullanılarak onların bağlı şerit durulayın. </li></ol></li></ol> Kan Örneklerinin 2. Hazırlık <ol><li> Toplama ve ayırmaSağlıklı bir gönüllüden taze tam kan. 17 <ol><li> Bir pıhtılaşma önleyici olarak etilendiamintetraasetik asit (EDTA) ihtiva eden bir tahliye borusu kan ilk mililitre toplamak ve özel olarak otomatik bir hematoloji analiz cihazı ile tam kan sayımı (CBC), bu örnek kullanın. </li><li> tahliye tüpler kullanılarak uygun bir antikoagülan kan hacmi toplayın. oluşumunu fibrin çalışma protokolüne ve sodyum sitrat parçası değilken akış odası deneyleri için standart antikoagülan heparin ya da hirudindir vardır. Not: Heparin açıklanan tüm deneyler için bir antikoagulan olarak kullanılmıştır. Not: kan miktarı yapılacak deneyler sayısına bağlıdır. Yaklaşık 3 şerit 1 borusu (7 mi). </li><li> Bir rotator bekleyen kan sulandırma üzerinde tüpler yerleştirin. Not: Tahlil Flebotomi 3 saat içinde tamamlanmalıdır. </li><li> Trombosit bakımından zengin plazma 250 g&#39;da 15 dakika boyunca santrifüj (PRP). gevşekçe paketlenmiş pelet olumsuz yönde etkilenmemesi için santrifüj mola kullanmayın. <ol><li> Birden fazla tüp toplandı zaman, tek bir konik santrifüj tüpü içinde kan havuzu. Not: Santrifüj PRP verim ve ayırıcı hücre &quot;kontaminasyon&quot; bağlı, daha yavaş ya da daha az uzun yapılabilir tercih. </li></ol></li><li> Çıkarın ve birkaç trombositler ile dolu kırmızı kan hücrelerinin veren PRP ve buffy coat atın. Bizim elimizde ortalama ul başına 13 ± 5 x 10 3 paketlenmiş kırmızı hücre fraksiyonunda trombosit sayısı ise (ortalama ± SD, n = 12): Not. </li></ol></li><li> kan Sulandırma <ol><li> 5 dakika ve 4 ml başına 20 saniye süreyle, 37 ° C&#39;de çözülme kan grubu AB (Rhesus D negatif), plazma. </li><li> otomatik bir hematoloji analiz cihazı kullanılarak 2.1.5 hazırlanan paketlenmiş kırmızı kan hücrelerinin hematokriti belirler. </li><li> Kan bankasında trombosit konsantrasyonunu belirlemek trombosit konsantresi tha hazırlanmışT, yukarıda kırmızı hücre fraksiyonu tekrar oluşturmak için kullanılır. </li><li> 1 ml&#39;lik bir örnek% 40 hematokrit ve 250 x 10³ trombosit / ul verecektir eritrosit, trombosit konsantresi hacmini hesaplar. Not: Hücrelerin Diğer hedef titreleri çalışma protokolüne bağlı olarak, keyfi olarak ayarlanabilir. </li><li> Transfer kırpılmış bir pipet ucu kullanılarak ve 1 ml lik bir numune hacmi elde edilene kadar trombosit konsantresi ilave taze tüpe kırmızı kan hücreleri ve plazma paketlendi. Not: Plazma trombüs oluşumu oranı üzerinde önemli bir etkiye sahip olduğu değişkenler okudu bağlı olarak, plazma fraksiyonu tüm sulandırılmış örneklerde eşit olmalıdır. Örneğin, sonuç etkileyebilir farklı donörden veya farklı antikoagülan alınan donma-çözülme ya da plazma tekrarladı. </li><li> yavaşça ters çevirerek yeniden kan karıştırın ve bir CBC gerçekleştirin. </li><li> trombosit fraksiyonun hacmi ikame edildiği bir &quot;boş&quot; kontrol numunesi hazırlanması% 0.9 su (kütle / hacim) sodyum klorür, aynı hacimde bir CBC kullanılarak yeniden kan endojen trombosit konsantrasyonu (yani, kan bankası trombositler) belirlemek gerekmektedir. </li></ol></li><li> etiketleme <ol><li> Pipet 1 mi 1 ul 5 mM Calcein AM (5 uM nihai konsantrasyon) ihtiva eden bir test tüpüne kan yeniden. Not: Diğer hücre boyalar 14 kullanılabilir. </li><li> ters çevirerek yavaşça karıştırın. </li><li> kullanımdan önce, 37 ° C&#39;de 5 dakika süreyle inkübe edilir. </li></ol></li></ol> 3. Perfüzyon Testi <ol><li> şerit dibinde yapıştırılır kollajen lifleri üzerinde nesnel odaklanın. İdeal olarak, bu odaklanma stratejisi için faz-kontrast veya diferansiyel girişim kontrast (DIC) ayarlarını kullanın. dijital seçilen Z-pozisyonları düzeltmek için deneme yazılımı &#39;seçilen çini bölgeler için ayarlayın akım Z&#39; seçeneğini seçin. </li><li> m deney yazılımı şeritli (xy) ilgi (ROI) bir bölge seçinDeney sırasında kaydedilir icroscope. Not: ROI keyfi bir perfüzyon şeritte içinde seçilen herhangi bir yüzey alanı olabilir. Nedenle bu göreceli olarak küçük olsa da, bu bölgede değişken akış profilinin yan etkilerden kaçınmak için yakın bir şeritli giriş ve çıkışına trombüs oluşumunu analiz için tavsiye edilir. YG yüzey alanı trombositlerin önemli sayıda içeren ya da sinyal tesviye izin trombüs gerekir. Bu protokolde YG 2 cm uzunluğundaki Lane ortasında 0.62 mm 2&#39;de elde edilen üç eşit yan tarafında bir görüntü dijital olarak dikilmiş toplamıdır. </li><li> yavaşça tersini örnekleri karıştırın ve otomatik sahnede Biochip bu sonraki yerleştirin. </li><li> sulandırılmış kan örnekleri içeren test tüplerinde Biochip girişi ile bağlantılı olan boru yerleştirin. </li><li> Test tüplerine bağlı olan kanallar için (istediğiniz gibi ya da diğer kesme stresleri) 50 din / cm2 pompayı başlatınpompa yazılımı kullanılarak yeniden kan örnekleri ihtiva etmektedir. Not: Diğer kayma gerilmeleri kullanılabilir. </li><li> Tutanak görüntüleri mikroskop edinimi ve deney yazılımı kullanarak gerçek zamanlı olarak 5 dakika boyunca her 15 sn. Not: Diğer zaman serisi deneysel set-up bağlı kullanılabilir. Not: Genellikle 100X büyütme (10X objektif ve 10X lens) kullanır, ancak daha yüksek (veya daha düşük) büyütme kolayca bir alternatif olarak kullanılabilir. </li></ol> 4. Yıkama Out <ol><li> sodyum hipoklorit (çamaşır suyu)% 0.5, ardından her tüp çıkışına bağlı ve damıtılmış su kullanılarak çok kanallı manifoldu veya pompaya bağlı yıkayın (h / h) ve su son olarak 0.1 M NaOH. tehlikeli atık olarak biyoçip girişine tutturulmuş boru atın. </li></ol> 5. Veri Analizi <ol><li> görüntü analiz yazılımı ile trombüs büyüme kinetikleri belirleyin. aşağıdaki komutlar ZEN2012 özgüdür. <ol&gt; <li> Trombositlerin yüzey kapsama belirlemek için eklenti Görüntü Analizi açın. </li><li> Olumlu bir sinyal ile ilişkilidir piksel yoğunluğunu belirlemek için İnteraktif sekmesini Analiz, yani bir yapışık trombosit ya da yapışan trombositler floresan eşiğini ayarlayın. </li><li> Otomatik olarak seçilen eşik arasında bir sinyal ile pikselleri ihtiva eden &quot;nesnelerin&quot; nin (mikron 2) ayrı yüzey alanlarını içerecek bir elektronik tablo oluşturmak için Tablolar oluşturma kullanın. Bu, her bir zaman noktası için gerçekleştirilir. Not: floresan eşikleri seçti edildikten sonra, analiz yazılımı otomatik olarak kriterleri yerine görünüm alanına &#39;nesneleri&#39; olarak algılar. Bu nesneler trombüsler, küçük trombosit agrega veya tek trombositler ve piksel sayısını kapsamaktadır. Her nesne ayrı ayrı e-tabloda listelenir. </li><li> xml formatında bu elektronik tabloları kaydedin ve bir elektronik tablo programı bunları açıksonraki hesaplamalar için. </li><li> Toplamı ile seçilen nesnelerin toplam yüzey alanları ve ölçüm alanına (mikron 2) toplam alanın tarafından sonucu bölün. Bu göreceli yüzey kaplama (%) verecektir. Her zaman noktası için bunu. </li><li> Perfüzyon, zamanın bir fonksiyonu olarak, bu yüzey Kapsamlı Konu ve söz konusu durumun trombüs büyümesi kinetiğini sonuçta, doğrusal regresyon ile eğimi hesaplanır. </li></ol></li></ol>

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B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assays+for+quality+control+of+platelets+for+transfusion.">Assays for quality control of platelets for transfusion.</a> ISBT Sci Series. 8, 221-224 (2013).</li><li>Andre, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anticoagulants+(thrombin+inhibitors)+and+aspirin+synergize+with+P2Y12+receptor+antagonism+in+thrombosis.">Anticoagulants (thrombin inhibitors) and aspirin synergize with P2Y12 receptor antagonism in thrombosis.</a> Circulation. 108, 2697-2703 (2003).</li><li>Casari, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=von+Willebrand+factor+mutation+promotes+thrombocytopathy+by+inhibiting+integrin+alphaIIbbeta3.">von Willebrand factor mutation promotes thrombocytopathy by inhibiting integrin alphaIIbbeta3.</a> J Clin Invest. 123, 5071-5081 (2013).</li><li>Gitz, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+platelet+survival+after+cold+storage+by+prevention+of+Glycoprotein+Ib&#945;+clustering+in+lipid+rafts.">Improved platelet survival after cold storage by prevention of Glycoprotein Ib&#945; clustering in lipid rafts.</a> Haematologica. , (2012).</li><li>Maurer-Spurej, E., Labrie, A., Brown, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Routine+Quality+Testing+of+Blood+Platelet+Transfusions+with+Dynamic+Light+Scattering.">Routine Quality Testing of Blood Platelet Transfusions with Dynamic Light Scattering.</a> Part Part Syst Char. 25, 99-104 (2008).</li><li>Van Kruchten, R., Cosemans, J. M., Heemskerk, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+whole+blood+thrombus+formation+using+parallel-plate+flow+chambers+-+a+practical+guide.">Measurement of whole blood thrombus formation using parallel-plate flow chambers - a practical guide.</a> Platelets. 23, 229-242 (2012).</li><li>Zwaginga, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow-based+assays+for+global+assessment+of+hemostasis.+Part+2:+current+methods+and+considerations+for+the+future.">Flow-based assays for global assessment of hemostasis. Part 2: current methods and considerations for the future.</a> J Thromb Haemost. 4, 2716-2717 (2006).</li><li>Zwaginga, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow-based+assays+for+global+assessment+of+hemostasis.+Part+1:+Biorheologic+considerations.">Flow-based assays for global assessment of hemostasis. Part 1: Biorheologic considerations.</a> J Thromb Haemost. 4, 2486-2487 (2006).</li></ol>

The authors have nothing to disclose.

Mikroakışkan akış odası deneyleri kan akan trombosit fonksiyonlarını araştırmak için mükemmel bir araçtır ve deneysel bağlamlarda farklı in vitro hemostaz değerlendirmek için kullanılır. Fakir laboratuvarlar arası standardizasyonun 9 rağmen bizim laboratuvar içinde deneysel varyasyon kabul edilebilir olduğunu göstermektedir. Bu güvenilir, belirli bir çalışma içinde (eşli) örnekleri karşılaştırmak için izin verir. Bu kan bankası koşullarında 11 trombos...

Hemostaz kısıtlı zamanmekansal bağlamda 1 hücreleri, proteinler, iyonlar ve dokuların kombine ve düzenlenmiş aktivite gerektirir. Kontrolsüz etkinliği kan pıhtılaşması ile ilgili bozuklukların bir spektrum içinde kanama ve tromboz ve morbidite ve mortaliteye neden olabilir. Bir mikroakışkan akış odası deneyi in vitro hemostazisi taklit zorlu bir tekniktir. Bu yaklaşım, kan trombositlerin için öncü bir role sahip hemostaz katılan süreçlerin karmaşık etkileşimin soruşturma sağlar. vasküler hasar ardından, trombositler, kan kaybını önlemek için maruz subendotelyal matris (gliko) proteinlere yapışır. Yapışma ardından, trombositler aktive ve yanıt olarak agrega matik ve nihayet bir trombosit ağının oluşumu, fibrin tarafından stabilize ve bir firmaya neden neden parakrin sinyal için, trombüs 2 sızdırmazlık yara. Diğer çoğu trombosit fonksiyon testleri, deney aksineAkış odaları ile ments dikkate kan akımının fiziksel parametre ve bu nedenle katılımcı hücreler ve biyomoleküllerin 3,4 tarihinde reolojinin etkisini alır. Akış odası deneyleri yapışkan matrisi, reoloji ve akış profilleri, hücresel kompozisyon, toksinler veya ilaç, iyonik kuvvet ve daha birçok varlığı da dahil olmak üzere süreçler hemostatik (alt) etkileyen önemli parametreler değiştirilerek hemostaz ve tromboz dönüm noktası anlayışlar yarattı. Son yirmi yılda, büyük örneklem hacimleri (10-100 ml) gerektiren düşük verim akım odası deneyleri mikroakışkan odaları genellikle küçük paralel plaka odadan oluşan ve kontrollü duvar kesme koşullarında 5 de tam kan perfüze için modern teknolojiyi dahil etmek gelişmiştir. donanım kurulum basitleştirilmiş ve daha az (kan) hacmi gereklidir çoğunlukla nedeniyle Microscaling önemli ölçüde deneme daha erişilebilir ve Versati render tahlil verimi arttıle. Örneğin, küçük laboratuar hayvanlarından kan Böylece hayvanlar kurban gerek kalmadan kullanılabilir. Genetiği değiştirilmiş farelerin kan örnekleri böylece hemostaz teşvik veya inhibe anahtar moleküller belirlenmesinde ve yeni temel anlayışlar 6 yardımcı olmaktadır. Özel araştırma laboratuarları çoğu hala yazılım tarafından blueprinted edilebilir Baskılı kalıplara polimerize polidimetilsiloksan (PDMS) 7 den, örneğin özel yapılmış akış odaları kullanın. Ortaya çıkan odası, ucuz tek kullanımlık ve kolayca post hoc analizi için demonte edilebilir. Ayrıca, temelde gemiler de dahil olmak üzere bifurkasyonlarında veya keskin dönüşler herhangi bir tasarım komutu üzerine inşa edilebilir. Bu avantaj da standardizasyon zaten akış odası deneyleri ile birincil sorun bu yana olumsuz ve PDMS özel odalar bu destekli değil yaptı. Bu belirli bir sorunun üstüne kaplama (şartlar), floresan probları, antikoagülan, geçici üzerindenumune alma ve analiz arasındaki kısa süreli olarak ve zaman tüm kötü 8 standardize edilmiştir. Bu değişkenlerin Standardizasyon zorlu ama yine de laboratuarlar arasında sonuçların karşılaştırılmasına olanak gerekmektedir. Bu konu Biorheology 9,10 Bilimsel ve Standardizasyon alt komite Tromboz ve hemostaz üzerine International Society önemli bir konudur. Trombosit konsantreleri (PC) trombositopeni ve / veya kanamaya neden çeşitli hastalıklardan mustarip hastalarda transfüzyon. Ama PC trombositler özellikle depolama süresinin 11 işlevinde, duyarsız bilinen bir bozulma süreci yaşlanma ve yaygın olarak trombosit saklama lezyon olarak anılacaktır bağlantılı. Bazen bu tür plateletler kez 12 transfüzyon dolaşımda geri iddia edilmektedir, ancak bunun için kanıt azdır. Ayrıca, bir PC oluşturan trombosit işlevselliği rutin test değil çünkü bu tür tahliller arasındaki ilişkiterapötik ya da profilaktik etkisi açık 13&#39;tür. Mikroakışkan akış odaları toplama ve ihracı arasındaki manipülasyonlar zincirini optimize etmek için PC trombosit fonksiyonlarını araştırmak için bir araç sunuyoruz. Biz daha önce 14,15 yayınlanmış ve burada tarif edildiği gibi PC doğrudan (eşli) karşılaştırmalar için güçlü bir araştırma aracıdır.

<table><tbody><tr><td>BD vacutainer tube with EDTA&amp;nbsp;</td><td>Becton, Dickinson and Company</td><td>368856</td><td></td></tr><tr><td>BD vacutainer tube with Heparin</td><td>Becton, Dickinson and Company</td><td>368480</td><td></td></tr><tr><td>BD vacutainer tube with Sodium Citrate</td><td>Becton, Dickinson and Company</td><td>366575</td><td></td></tr><tr><td>Hirudin Blood tube</td><td>Roche</td><td>6675751 001</td><td></td></tr><tr><td>BD vacutainer Eclipse</td><td>Becton, Dickinson and Company</td><td>368650</td><td>Blood collection needle with preattached holder</td></tr><tr><td>Pipette tips 100-1,000</td><td>Greiner bio-one</td><td>740290</td><td></td></tr><tr><td>Pipette tips 2-200</td><td>Greiner bio-one</td><td>739280</td><td></td></tr><tr><td>Pipette tips 1-10</td><td>Eppendorf</td><td>A08928</td><td></td></tr><tr><td>Tube 5 ml</td><td>Simport</td><td>11691380</td><td></td></tr><tr><td>Conical tube 15 ml</td><td>Greiner bio-one</td><td>1888271</td><td></td></tr><tr><td>Conical tube 50 ml</td><td>Greiner bio-one</td><td>227261</td><td></td></tr><tr><td>10 ml Syringe</td><td>BD</td><td>309604</td><td></td></tr><tr><td>Precision wipes</td><td>Kimtech</td><td>5511</td><td></td></tr><tr><td>Vena8 Fluoro+ Biochips</td><td>Cellix</td><td>188V8CF-400-100-02P10</td><td>Named in &lt;strong&gt;Figure S1&lt;/strong&gt; A as &#039;Biochip&#039;</td></tr><tr><td>Vena8 Tubing</td><td>Cellix</td><td>TUBING-TYGON-B1IC-B1OC-ROLL 100F</td><td>Named in &lt;strong&gt;Figure S1&lt;/strong&gt; B as &#039;Disposable tubing&#039;</td></tr><tr><td>Vena8 Needles</td><td>Cellix</td><td>SS-P-B1IC-B1OC-PACK200</td><td>Named in &lt;strong&gt;Figure S1&lt;/strong&gt; B as &#039;Pin&#039;</td></tr><tr><td>Connectors for single inlet cables of biochips</td><td>Cellix</td><td>CONNECTORS-B1IC-PACK100</td><td></td></tr><tr><td>Multiflow8 connect</td><td>Cellix</td><td>MF8-CONNECT-BIC3-N-THROMBOSIS</td><td>Named in &lt;strong&gt;Figure S1&lt;/strong&gt; B as &#039;Reusable tubing&#039; and &#039;Splitter&#039;</td></tr><tr><td>Humidified box</td><td>Cellix</td><td>HUMID-BOX</td><td></td></tr><tr><td>Software microfluidic pump</td><td>Cellix</td><td>N/A</td><td>Venaflux Assay</td></tr><tr><td>Horm Collagen</td><td>Takeda/Nycomed</td><td>1130630</td><td>Native equine tendon collagen (type I)&lt;br/&gt; Isotonic glucose solution to dilute collagen is supplemented</td></tr><tr><td>HEPES buffered saline (HBS)</td><td>in house preparation</td><td>in house preparation</td><td>10 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffered saline (0.9% (w/v) NaCl, pH 7.4)</td></tr><tr><td>Blocking buffer</td><td>in house preparation</td><td>in house preparation</td><td>1.0% (w/v) bovine serum albumin and 0.1% (w/v) glucose in HBS</td></tr><tr><td>Calcein AM</td><td>Molecular probes</td><td>C1430</td><td></td></tr><tr><td>Bleach 10%</td><td>in house preparation</td><td>in house preparation</td><td></td></tr><tr><td>0.1 M NaOH</td><td>in house preparation</td><td>in house preparation</td><td></td></tr><tr><td>Denaturated alcohol</td><td>Fiers</td><td>T0011.5</td><td></td></tr><tr><td>Mirus Evo Nanopump</td><td>Cellix</td><td>188-MIRUS-PUMP-EVO</td><td>with Multiflow8. Named in &lt;strong&gt;Figure S1&lt;/strong&gt; A as &#039;Pump&#039; and &#039;Manifold&#039;</td></tr><tr><td>Microscope</td><td>Zeiss</td><td>Axio Observer Z1</td><td>equipped with a colibri-LED and high resolution CCD camera</td></tr><tr><td>Software microscope&amp;nbsp;</td><td>Zeiss</td><td>N/A</td><td>ZEN 2012</td></tr><tr><td>Hematology analyzer</td><td>Sysmex</td><td>N/A</td><td></td></tr><tr><td>Table Top Centrifuge</td><td>Eppendorf</td><td>521-0095</td><td></td></tr><tr><td>Platelet incubater</td><td>Helmer</td><td>PF-48i</td><td></td></tr><tr><td>Incubation water bath</td><td>GFL</td><td>1013</td><td></td></tr><tr><td>Pipette</td><td>Brand</td><td>A03429</td><td></td></tr><tr><td>Tube Roller</td><td>Ratek</td><td>BTR5-12V</td><td></td></tr><tr><td>Sterile docking device</td><td>Terumo BCT</td><td>TSCD</td><td></td></tr><tr><td>Tubing Sealer</td><td>Terumo BCT</td><td>AC-155</td><td></td></tr><tr><td>Vortex</td><td>VWR</td><td>58816-121</td><td></td></tr></tbody></table>

microfluidic flow chambers using reconstituted blood to model hemostasis and platelet transfusion in vitro

Blood platelets prepared for transfusion gradually lose hemostatic function during storage. Platelet function can be investigated using a variety of (indirect) in vitro experiments, but none of these is as comprehensive as microfluidic flow chambers. In this protocol, the reconstitution of thrombocytopenic fresh blood with stored blood bank platelets is used to simulate platelet transfusion. Next, the reconstituted sample is perfused in microfluidic flow chambers which mimic hemostasis on exposed subendothelial matrix proteins. Effects of blood donation, transport, component separation, storage and pathogen inactivation can be measured in paired experimental designs. This allows reliable comparison of the impact every manipulation in blood component preparation has on hemostasis. Our results demonstrate the impact of temperature cycling, shear rates, platelet concentration and storage duration on platelet function. In conclusion, this protocol analyzes the function of blood bank platelets and this ultimately aids in optimization of the processing chain including phlebotomy, transport, component preparation, storage and transfusion.

Analiz içi varyasyon göstermek için, üç aynı yeniden tam kan numuneleri kollajen kaplı yüzeylerin (Şekil 1) üzerinde eşzamanlı olarak perfüze edildi. Bu% 8.7 bir farklılaşma katsayısı ile sonuçlanmıştır. Bu istatistik ile ilgili örnekler arasında kıyas izin kabul edilebilir içi tahlil ve laboratuvarda varyasyon göstermektedir. Burada tarif ticari akış odasının giriş ölçüm göz...

Watch this Scientific Journal Video about Microfluidic Flow Chambers Using Reconstituted Blood to Model Hemostasis and Platelet Transfusion In Vitro at JoVE.com

Microfluidic Flow Chambers Using Reconstituted Blood to Model Hemostasis and Platelet Transfusion In Vitro

Platelet transfusion and hemostasis was modeled using blood reconstitution and microfluidic flow chambers to investigate the function of blood banking platelets. The data demonstrate the consequences of platelet storage lesion on hemostasis, in vitro.

Mikroakışkan Akış Chambers Hemostaz ve Trombosit Transfüzyon Model Sulandırılarak Kan kullanma<em&gt; İn Vitro</em

Blood platelets prepared for transfusion gradually lose hemostatic function during storage. Platelet function can be investigated using a variety of ...

microfluidic-flow-chambers-using-reconstituted-blood-to-model

Research

JoVE Journal

Bioengineering

Microfluidic Flow Chambers Using Reconstituted Blood to Model Hemostasis and Platelet Transfusion In Vitro

9.3K Görüntüleme.  Belgium Red Cross-Flanders. Platelet transfusion and hemostasis was modeled using blood reconstitution and microfluidic flow chambers to investigate the function of blood banking platelets. The data demonstrate the consequences of platelet storage lesion on hemostasis, in vitro. 

Video: Microfluidic Flow Chambers Using Reconstituted Blood to Model Hemostasis and Platelet Transfusion In Vitro

Microfluidic Device for Recreating a Tumor Microenvironment in Vitro

We have developed a microfluidic device that mimics the delivery and systemic clearance of drugs to heterogeneous three-dimensional tumor tissues in vitro. Nutrients delivered by vasculature fail to reach all parts of tumors, giving rise to heterogeneous microenvironments consisting of viable, quiescent and necrotic cell types. Many cancer drugs fail to effectively penetrate and treat all types of cells because of this heterogeneity. Monolayers of cancer cells do not mimic this heterogeneity, making it difficult to test cancer drugs with a suitable in vitro model. Our microfluidic devices were fabricated out of PDMS using soft lithography. Multicellular tumor spheroids, formed by the hanging drop method, were inserted and constrained into rectangular chambers on the device and maintained with continuous medium perfusion on one side. The rectangular shape of chambers on the device created linear gradients within tissue. Fluorescent stains were used to quantify the variability in apoptosis within tissue. Tumors on the device were treated with the fluorescent chemotherapeutic drug doxorubicin, time-lapse microscopy was used to monitor its diffusion into tissue, and the effective diffusion coefficient was estimated. The hanging drop method allowed quick formation of uniform spheroids from several cancer cell lines. The device enabled growth of spheroids for up to 3 days. Cells in proximity of flowing medium were minimally apoptotic and those far from the channel were more apoptotic, thereby accurately mimicking regions in tumors adjacent to blood vessels. The estimated value of the doxorubicin diffusion coefficient agreed with a previously reported value in human breast cancer. Because the penetration and retention of drugs in solid tumors affects their efficacy, we believe that this device is an important tool in understanding the behavior of drugs, and developing new cancer therapeutics.

Microfluidic Device for Recreating a Tumor Microenvironment in Vitro

We present the procedure for fabrication and operation of a microfluidic device that recreates heterogeneous tumor microenvironments in vitro. The variability in apoptosis within tumor tissue was quantified using fluorescent stains and the effective diffusion coefficient of the chemotherapeutic drug doxorubicin into tumor tissue was evaluated.

Bir Tümör Mikroçevre yeniden oluşturmak için mikroakışkan Cihazı<em&gt; In vitro</em

We have developed a microfluidic device that mimics the delivery and systemic clearance of drugs to heterogeneous three-dimensional tumor tissues in ...

Biyomühendislik

Separating Beads and Cells in Multi-channel Microfluidic Devices Using Dielectrophoresis and Laminar Flow

Microfluidic devices have advanced cell studies by providing a dynamic fluidic environment on the scale of the cell for studying, manipulating, sorting and counting cells. However, manipulating the cell within the fluidic domain remains a challenge and requires complicated fabrication protocols for forming valves and electrodes, or demands specialty equipment like optical tweezers. Here, we demonstrate that conventional printed circuit boards (PCB) can be used for the non-contact manipulation of cells by employing dielectrophoresis (DEP) for bead and cell manipulation in laminar flow fields for bioactuation, and for cell and bead separation in multichannel microfluidic devices. First, we present the protocol for assembling the DEP electrodes and microfluidic devices, and preparing the cells for DEP. Then, we characterize the DEP operation with polystyrene beads. Lastly, we show representative results of bead and cell separation in a multichannel microfluidic device. In summary, DEP is an effective method for manipulating particles (beads or cells) within microfluidic devices.

Dielectrophoresis (DEP) is an effective method to manipulate cells. Printed circuit boards (PCB) can provide inexpensive, reusable and effective electrodes for contact-free cell manipulation within microfluidic devices. By combining PDMS-based microfluidic channels with coverslips on PCBs, we demonstrate bead and cell manipulation and separation within multichannel microfluidic devices.

Çok kanallı mikroakışkan Cihazlar ayırmak Boncuk ve Hücreler Dielectrophoresis ve Laminar Flow

Microfluidic devices have advanced cell studies by providing a dynamic fluidic environment on the scale of the cell for studying, manipulating, sorting ...

Parallel-plate Flow Chamber and Continuous Flow Circuit to Evaluate Endothelial Progenitor Cells under Laminar Flow Shear Stress

The overall goal of this method is to describe a technique to subject adherent cells to laminar flow conditions and evaluate their response to well quantifiable fluid shear stresses1.
Our flow chamber design and flow circuit (Fig. 1) contains a transparent viewing region that enables testing of cell adhesion and imaging of cell morphology immediately before flow (Fig. 11A, B), at various time points during flow (Fig. 11C), and after flow (Fig. 11D). These experiments are illustrated with human umbilical cord blood-derived endothelial progenitor cells (EPCs) and porcine EPCs2,3.
This method is also applicable to other adherent cell types, e.g. smooth muscle cells (SMCs) or fibroblasts.
The chamber and all parts of the circuit are easily sterilized with steam autoclaving. In contrast to other chambers, e.g. microfluidic chambers, large numbers of cells (&gt; 1 million depending on cell size) can be recovered after the flow experiment under sterile conditions for cell culture or other experiments, e.g. DNA or RNA extraction, or immunohistochemistry (Fig. 11E), or scanning electron microscopy5. The shear stress can be adjusted by varying the flow rate of the perfusate, the fluid viscosity, or the channel height and width. The latter can reduce fluid volume or cell needs while ensuring that one-dimensional flow is maintained. It is not necessary to measure chamber height between experiments, since the chamber height does not depend on the use of gaskets, which greatly increases the ease of multiple experiments. Furthermore, the circuit design easily enables the collection of perfusate samples for analysis and/or quantification of metabolites secreted by cells under fluid shear stress exposure, e.g. nitric oxide (Fig. 12)6.

We are describing a method to subject adherent cells to laminar flow shear stress in a sterile continuous flow circuit. The cells' adhesion, morphology can be studied through the transparent chamber, samples obtained from the circuit for metabolite analysis and cells harvested after shear exposure for future experiments or culture.

Laminer Akış Kesme Stres altında endotel progenitör hücrelerin değerlendirin Paralel plakalı Akış Odası ve Sürekli Akış Devre

The overall goal of this method is to describe a technique to subject adherent cells to laminar flow conditions and evaluate their response to well ...

Endothelialized Microfluidics for Studying Microvascular Interactions in Hematologic Diseases

Advances in microfabrication techniques have enabled the production of inexpensive and reproducible microfluidic systems for conducting biological and biochemical experiments at the micro- and nanoscales 1,2. In addition, microfluidics have also been specifically used to quantitatively analyze hematologic and microvascular processes, because of their ability to easily control the dynamic fluidic environment and biological conditions3-6. As such, researchers have more recently used microfluidic systems to study blood cell deformability, blood cell aggregation, microvascular blood flow, and blood cell-endothelial cell interactions6-13.However, these microfluidic systems either did not include cultured endothelial cells or were larger than the sizescale relevant to microvascular pathologic processes. A microfluidic platform with cultured endothelial cells that accurately recapitulates the cellular, physical, and hemodynamic environment of the microcirculation is needed to further our understanding of the underlying biophysical pathophysiology of hematologic diseases that involve the microvasculature.
Here, we report a method to create an "endothelialized" in vitro model of the microvasculature, using a simple, single mask microfabrication process in conjunction with standard endothelial cell culture techniques, to study pathologic biophysical microvascular interactions that occur in hematologic disease. This "microvasculature-on-a-chip" provides the researcher with a robust assay that tightly controls biological as well as biophysical conditions and is operated using a standard syringe pump and brightfield/fluorescence microscopy. Parameters such as microcirculatory hemodynamic conditions, endothelial cell type, blood cell type(s) and concentration(s), drug/inhibitory concentration etc., can all be easily controlled. As such, our microsystem provides a method to quantitatively investigate disease processes in which microvascular flow is impaired due to alterations in cell adhesion, aggregation, and deformability, a capability unavailable with existing assays.

A method to culture an endothelial cell monolayer throughout the entire inner 3D surface of a microfluidic device with microvascular-sized channels (&lt;30 &mu;m) is described. This in vitro microvasculature model enables the study of biophysical interactions between blood cells, endothelial cells, and soluble factors in hematologic diseases.

Hematolojik Hastalıklarında Mikrovasküler Etkileşimleri Öğrenmenin Endothelialized Mikroakiskan

Advances in  microfabrication techniques have enabled the production of inexpensive and  reproducible microfluidic systems for conducting biological and ...

Systematic Analysis of In Vitro Cell Rolling Using a Multi-well Plate Microfluidic System

A major challenge for cell-based therapy is the inability to systemically target a large quantity of viable cells with high efficiency to tissues of interest following intravenous or intraarterial infusion. Consequently, increasing cell homing is currently studied as a strategy to improve cell therapy. Cell rolling on the vascular endothelium is an important step in the process of cell homing and can be probed in-vitro using a parallel plate flow chamber (PPFC). However, this is an extremely tedious, low throughput assay, with poorly controlled flow conditions. Instead, we used a multi-well plate microfluidic system that enables study of cellular rolling properties in a higher throughput under precisely controlled, physiologically relevant shear flow1,2. In this paper, we show how the rolling properties of HL-60 (human promyelocytic leukemia) cells on P- and E-selectin-coated surfaces as well as on cell monolayer-coated surfaces can be readily examined. To better simulate inflammatory conditions, the microfluidic channel surface was coated with endothelial cells (ECs), which were then activated with tumor necrosis factor-&#945; (TNF-&#945;), significantly increasing interactions with HL-60 cells under dynamic conditions. The enhanced throughput and integrated multi-parameter software analysis platform, that permits rapid analysis of parameters such as rolling velocities and rolling path, are important advantages for assessing cell rolling properties in-vitro. Allowing rapid and accurate analysis of engineering approaches designed to impact cell rolling and homing, this platform may help advance exogenous cell-based therapy.

Systematic Analysis of In Vitro Cell Rolling Using a Multi-well Plate Microfluidic System

This study used a multi-well plate microfluidic system, significantly increasing throughput of cell rolling studies under physiologically relevant shear flow. Given the importance of cell rolling in the multi-step cell homing cascade and the importance of cell homing following systemic delivery of exogenous populations of cells in patients, this system offers potential as a screening platform to improve cell-based therapy.

Sistematik Analizi<em&gt; In Vitro</emÇok-çukurlu plaka mikroakışkan Sistemi ile&gt; Hücre Rolling

A major challenge for cell-based therapy is the inability to systemically target a large quantity of viable cells with high efficiency to tissues of ...

In Vitro Model of Physiological and Pathological Blood Flow with Application to Investigations of Vascular Cell Remodeling

Vascular disease is a common cause of death within the United States. Herein, we present a method to examine the contribution of flow dynamics towards vascular disease pathologies. Unhealthy arteries often present with wall stiffening, scarring, or partial stenosis which may all affect fluid flow rates, and the magnitude of pulsatile flow, or pulsatility index. Replication of various flow conditions is the result of tuning a flow pressure damping chamber downstream of a blood pump. Introduction of air within a closed flow system allows for a compressible medium to absorb pulsatile pressure from the pump, and therefore vary the pulsatility index. The method described herein is simply reproduced, with highly controllable input, and easily measurable results. Some limitations are recreation of the complex physiological pulse waveform, which is only approximated by the system. Endothelial cells, smooth muscle cells, and fibroblasts are affected by the blood flow through the artery. The dynamic component of blood flow is determined by the cardiac output and arterial wall compliance. Vascular cell mechano-transduction of flow dynamics may trigger cytokine release and cross-talk between cell types within the artery. Co-culture of vascular cells is a more accurate picture reflecting cell-cell interaction on the blood vessel wall and vascular response to mechanical signaling. Contribution of flow dynamics, including the cell response to the dynamic and mean (or steady) components of flow, is therefore an important metric in determining disease pathology and treatment efficacy. Through introducing an in vitro co-culture model and pressure damping downstream of blood pump which produces simulated cardiac output, various arterial disease pathologies may be investigated.

In Vitro Model of Physiological and Pathological Blood Flow with Application to Investigations of Vascular Cell Remodeling

This protocol replicates physiological or pathological blood flow in vitro to aid in determining cell response in disease pathologies. By introducing a pressure damping chamber downstream of a blood pump, blood flow across the vasculature can be recapitulated and imposed on a monolayer of vascular endothelium or a mimetic co-culture.

Vasküler Hücre Remodeling Soruşturma Fizyolojik in vitro Modeli ve Uygulaması ile Patolojik Kan Akış

Vascular disease is a common cause of death within the United States. Herein, we present a method to examine the contribution of flow dynamics towards ...

A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time

Microfluidic models of hemostasis assess platelet function under conditions of hydrodynamic shear, but in the presence of anticoagulants, this analysis is restricted to platelet deposition only. The intricate relationship between Ca2+-dependent coagulation and platelet function requires careful and controlled recalcification of blood prior to analysis. Our setup uses a Y-shaped mixing channel, which supplies concentrated Ca2+/Mg2+ buffer to flowing blood just prior to perfusion, enabling rapid recalcification without sample stasis. A ten-fold difference in flow velocity between both reservoirs minimizes dilution. The recalcified blood is then perfused in a collagen-coated analysis chamber, and differential labeling permits real-time imaging of both platelet and fibrin deposition using fluorescence video microscopy. The system uses only commercially available tools, increasing the chances of standardization. Reconstitution of thrombocytopenic blood with platelets from banked concentrates furthermore models platelet transfusion, proving its use in this research domain. Exemplary data demonstrated that coagulation onset and fibrin deposition were linearly dependent on the platelet concentration, confirming the relationship between primary and secondary hemostasis in our model. In a timeframe of 16 perfusion min, contact activation did not take place, despite recalcification to normal Ca2+ and Mg2+ levels. When coagulation factor XIIa was inhibited by corn trypsin inhibitor, this time frame was even longer, indicating a considerable dynamic range in which the changes in the procoagulant nature of the platelets can be assessed. Co-immobilization of tissue factor with collagen significantly reduced the time to onset of coagulation, but not its rate. The option to study the tissue factor and/or the contact pathway increases the versatility and utility of the assay.

This paper describes an experimental model of hemostasis that simultaneously measures platelet function and coagulation. Platelet and fibrin fluorescence is measured in real-time, and platelet adhesion rate, coagulation rate, and onset of coagulation are determined. The model is used to determine platelet procoagulant properties under flow in concentrates for transfusion.

Trombosit Transfüzyon ve Hemostaz için bir mikroakışkan Akış Odası Modeli Gerçek zamanlı Trombosit Birikimi ve Fibrin oluşumu Tedbirleri

Microfluidic models of hemostasis assess platelet function under conditions of hydrodynamic shear, but in the presence of anticoagulants, this analysis is ...

In Vitro Microfluidic Disease Model to Study Whole Blood-Endothelial Interactions and Blood Clot Dynamics in Real-Time

The formation of blood clots involves complex interactions between endothelial cells, their underlying matrix, various blood cells, and proteins. The endothelium is the primary source of many of the major hemostatic molecules that control platelet aggregation, coagulation, and fibrinolysis. Although the mechanism of thrombosis has been investigated for decades, in vitro studies mainly focus on situations of vascular damage where the subendothelial matrix gets exposed, or on interactions between cells with single blood components. Our method allows studying interactions between whole blood and an intact, confluent vascular cell network.
By utilizing primary human endothelial cells, this protocol provides the unique opportunity to study the influence of endothelial cells on thrombus dynamics and gives&#160;valuable insights into the pathophysiology of thrombotic disease. The use of custom-made microfluidic flow channels allows application of disease-specific vascular geometries and model specific morphological vascular changes. The development of a thrombus is recorded in real-time and quantitatively characterized by platelet adhesion and fibrin deposition. The effect of endothelial function in altered thrombus dynamics is determined by postanalysis through immunofluorescence staining of specific molecules.
The representative results describe the experimental setup, data collection, and data analysis. Depending on the research question, parameters for every section can be adjusted including cell type, shear rates, channel geometry, drug therapy, and postanalysis procedures. The protocol is validated by quantifying thrombus formation on the pulmonary artery endothelium of patients with chronic thromboembolic disease.

We present an in vitro vascular disease model to investigate whole blood interactions with patient-derived endothelium. This system allows the study of thrombogenic properties of primary endothelial cells under various circumstances. The method is especially suited to evaluate in situ thrombogenicity and anticoagulation therapy during different phases of coagulation.

In Vitro Mikroakışkan Hastalık Modeli Gerçek Zamanlı Olarak Tam Kan-Endotel Etkileşimleri ve Kan Pıhtısı Dinamikleri Çalışma

The formation of blood clots involves complex interactions between endothelial cells, their underlying matrix, various blood cells, and proteins. The ...

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An In Vitro Hemodynamic Loop Model to Investigate the Hemocytocompatibility and Host Cell Activation of Vascular Medical Devices

In this study, the hemocompatibility of tubes with an inner diameter of 5 mm made of polyvinyl chloride (PVC) and coated with different bioactive conjugates was compared to uncoated PVC tubes, latex tubes, and a stent for intravascular application that was placed inside the PVC tubes. Evaluation of hemocompatibility was done using an in vitro hemodynamic loop model that is recommended by the ISO standard 10993-4. The tubes were cut into segments of identical length and closed to form loops avoiding any gap at the splice, then filled with human blood and rotated in a water bath at 37 &#176;C for 3 hours. Thereafter, the blood inside the tubes was collected for the analysis of whole blood cell count, hemolysis (free plasma hemoglobin), complement system (sC5b-9), coagulation system (fibrinopeptide A), and leukocyte activation (polymorphonuclear elastase, tumor necrosis factor and interleukin-6). Host cell activation was determined for platelet activation, leukocyte integrin status and monocyte platelet aggregates using flow cytometry. The effect of inaccurate loop closure was examined with x-ray microtomography and scanning electron microscopy, that showed thrombus formation at the splice. Latex tubes showed the strongest activation of both plasma and cellular components of the blood, indicating a poor hemocompatibility, followed by the stent group and uncoated PVC tubes. The coated PVC tubes did not show a significant decrease in platelet activation status, but showed an increased in complement and coagulation cascade compared to uncoated PVC tubes. The loop model itself did not lead to the activation of cells or soluble factors, and the hemolysis level was low. Therefore, the presented in vitro hemodynamic loop model avoids excessive activation of blood components by mechanical forces and serves as a method to investigate in vitro interactions between donor blood and vascular medical devices.

Presented here is a protocol for a standardized in vitro hemodynamic loop model. This model allows to test the hemocompatibility of perfusion tubes or vascular stents to be in accordance with ISO (International Organization for Standardization) standard 10993-4.

Vasküler Tıbbi Cihazların Hemositokomisyonla uyumluluğunu ve Konak Hücre Aktivasyonunu Araştırmak için Bir In Vitro Hemodinamik Döngü Modeli

In this study, the hemocompatibility of tubes with an inner diameter of 5 mm made of polyvinyl chloride (PVC) and coated with different bioactive ...

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<meta charset="utf8"></head><body>Travma ve Transfüzyonda Trombosit Fonksiyonunu Değerlendirme Platformu

Microfluidics in Assessing Platelet Function

Microfluidics incorporate physiologically relevant substrates and flows that mimic the vasculature and are, therefore, a valuable tool for studying aspects of thrombosis and hemostasis. At high-shear environments simulating arterial flow, a microfluidic assay facilitates the study of platelet function, as platelet-rich thrombi form in a localized stenotic region of a flow channel. Utilizing devices that allow for small sample volume can additionally aid in evaluating platelet function under flow from volume-limited patient samples or animal models. Studying trauma patient samples or samples following platelet product transfusion may aid in directing therapeutic strategies for patient populations in which platelet function is critical. Effects of platelet inhibition via pharmacological agents can also be studied in this model. The objective of this protocol is to establish a microfluidic platform that incorporates physiologic flow, biological surfaces, and relevant hemostatic mechanisms to assess platelet function with implications for the study of trauma induced coagulopathy and transfusion medicine.

<meta charset="utf8"></head><body>Trombosit Fonksiyonunun Değerlendirilmesinde Mikroakışkanlar

Platelet function under flow can be assessed and simulated hemostatic resuscitation can be modeled using a microfluidic device, which has applications in trauma and transfusion medicine.

Trombosit Fonksiyonunun Değerlendirilmesinde Mikroakışkanlar

Microfluidics incorporate physiologically relevant substrates and flows that mimic the vasculature and are, therefore, a valuable tool for studying ...

Mikroakışkan Akış Chambers Hemostaz ve Trombosit Transfüzyon Model Sulandırılarak Kan kullanma

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