Z.C. destek Dartmouth başlangıç Fonu ve Branco Weiss - Derneği Bilim Kardeşliği, ETH Zürih tarafından yönetilen için kabul eder. Yazarlar Drs. Larry A. Taber, Benjamen A. Filas, Qiaohang Guo ve Yunfei Shi yararlı tartışmalar için yanı sıra adsız yorumcular Yorumlar için teşekkür ederim. Bu malzeme Ulusal Bilim Vakfı Yüksek Lisans Araştırma Bursu Grant No altında tarafından desteklenen çalışma üzerine kuruludur DGE-1313911. Herhangi bir görüş, bulgular ve sonuç ya da öneriler bu malzeme ifade yazarlar (s) ve mutlaka Ulusal Bilim Vakfı görüşlerini yansıtmamaktadır.

1. doku kültürü medya hazırlanması
<ol><li>0,5 L şişe Dulbecco'nın modifiye kartal Orta (DMEM) 4,5 g/M glikoz, sodyum bikarbonat ve L-glutamin ile kültür ortamı için temel olarak kullanın.</li>
	<li>Bir steril laminar akış başlık, antibiyotikler 10 mL DMEM 0.5 litre için ekleyin.</li>
	<li>Steril bir pipet kullanarak, DMEM antibiyotik çözüm 50 mL steril 50 mL konik tüp aktarın.</li>
	<li>Piliç serum 50 mL steril başlıklı 0,5 L şişede kalan DMEM antibiyotik çözüm ekleyin.</li>
	<li>Nihai çözüm (ahiret için piliç kültür ortamı [CCM] olarak 50 mL konik tüp aliquots-20 ° C'de olarak adlandırılır) saklamak</li>
</ol>2. yumurta kuluçka
<ol><li>Kullanım hassas döllenmiş belirli patojen ücretsiz beyaz Livorno tavuk yumurtası temizlemek için % 70 etanol ile siliyor. Yumurta sahipleri üzerinde boyuna yönlendirme düzenleyin.</li>
	<li>Bir hedef sıcaklık 37,5 ° C ayarlayın ve 48-%55 nem korumak için bir kuluçka açın. Nem oranı da kuluçka için uygun bir miktar su ekleyerek kontrol edilir.</li>
	<li>HH11-13 olarak yaklaşık 40-44 h yumurtaları kuluçkaya.</li>
	<li>İzin için püskürtme/Temizleme % 70 etanol ile önce yaklaşık 15-30 dakika oda sıcaklığında yumurta sakin olun.</li>
</ol>3. çekme cam kılcal
<ol><li>1.0 mm bir dış çapı ve 0,5 mm bir iç çapı 10 cm uzunluğundaki cam kılcal tüpler bir micropipette çektirmenin bağlayın.</li>
	<li>Isı ayarlama ve parametreleri 750 ve 400, sırasıyla çekin. İnce iğneler kapiller boruyu için çekme düğmesine basın.</li>
</ol>4. filtre kağıdı taşıyıcı yöntemi
<ol><li>Daireler yaklaşık 3 cm çapında filtre kağıdı kesti.</li>
	<li>Bir dikdörtgen kabaca bir delik zımba kullanarak Daire 2 cm x 1 cm kesti. Herhangi bir çıkıntılı kaldırmak veya keskin köşeler emin olun.</li>
</ol>5. embriyo hasat ve hazırlık
<ol><li>Alt yumurta çatlamak, kabuk yavaşça ayır ve dikkatle içeriği 150 mm x 15 mm petri kabına mevduat. Embriyo yan doldu önlemek için aynı yönde onları çatlama süre inkübe yumurta getirin.</li>
	<li>Bir tek kullanımlık Pasteur pipet kullanarak ince albümin kaldırın.</li>
	<li>Kalın albümin künt uçlu forseps kullanarak sarısı ayırın. Kalın albümin sarısının üstündeki künt uçlu forseps ile hafifçe kazıma kaldırıldığından emin olmak.</li>
	<li>İnce uçlu forseps ortalamak ve filtre kağıdı yüzük Yüzük uzun ekseni embriyo uzun ekseni ile eşleşen embriyo üzerinde yer için kullanın.</li>
	<li>Filtre kağıdı halka makasla çevreleyen sarısı kesti.</li>
	<li>Yüzük ve embriyo sarısı kapalı nerede sarısını ilk kesildi sitesi yönelik eğik bir yönde çekin.</li>
	<li>İki sıralı 100-mm yemeklerinde oda sıcaklığında 1 fosfat tamponlu tuz (PBS) x ile embriyo durulayın.</li>
	<li>Bir filtre kağıdı halka ilk 35-mm petri kabına yerleştirin. Sonra embriyo dorsal tarafta filtre kağıdı zaten 35-mm kabında yerleştirin.</li>
	<li>Paslanmaz Çelik Yüzük filtre kağıdı sandviç üstüne yerleştirin. Embriyo zarar vermeyeceğine emin olun.</li>
	<li>Önceden hazırlanmış CCM 3 mL her petri kabına ekleyin.</li>
	<li>Her embriyo VM hafifçe çekti kapiller iğne embriyo ve VM uzak soyulması, (ön) üzerinde doğru anterior sonundan başlayarak ve ilerleme-e doğru (Şekil 1A) notochord üstte kaymağını tarafından kaldırın.</li>
	<li>Sekiz 35-mm Petri yemekler (nem korumak için) doymuş su hassas görev mendil ile kaplı bir 150 mm çanak içine yerleştirin.</li>
	<li>Yere yapışmalı Plastik torba 150 mm petri kabına sonra % 95'i O2 ve %5 CO2oluşan bir gaz karışımı ile çantayı doldurun.</li>
	<li>Çantayı mühür ve 37,5 ° C kuluçka makinesine koyun.</li>
	<li>Bir ek 27 h için embriyo HH15-HH16 kadar (Şekil 1B) kuluçkaya.</li>
</ol>6. inducing yüzey gerilimi
<ol><li>Embriyolar inkübatör kaldırmak ve onları görüntü için bir optik koherens tomografi (OCT) sistemi kullanın. Nöral tüp (NT) (Şekil 2) burulma açısı belirlemek için kullanım Ekim</li>
	<li>Işık mikroskop için embriyo transfer ve 10 X büyütme oranında görselleştirin. 200 microliter pipet artımlı olarak medya 0.2 mL petri kabına kaldırmak için kullanın.</li>
	<li>Embriyo medya-AIR arabirimiyle etkilerini gözlemlemek için her aralıkta aydınlık alan görüntü alabilir.</li>
	<li>Torsiyon (Şekil 1 c) embriyo üzerinde yüzey gerilimi indükler kadar medyayı çıkarın.</li>
	<li>OCT sistemi bir kez daha embriyo denetlemek karşılaştırma için son bir burulma açısı kurmak için kullanılarak embriyo görüntü.  Not: Diseksiyon mikroskop kullanarak parlak-alan görüntüleri elde. Ekli bir mikroskop ile bir optik koherens tomografi sistemi kesitsel görüntü yığınları canlı embriyo elde etmek için kullanılmıştır. Görüntüleri 3 x 10 mm x 3 mm3 tarama etki alanında elde sonra bir düşsel bilgisayar yazılımı içinde işlenen edildi. Son olarak, fiziksel model görüntüleri ile bir dijital tek objektifli refleks fotoğraf makinesi alındı.</li>
</ol>7. yüzey gerilimi/VM güçlerinin fiziksel modelleme
<ol><li>HH14-17'ticari modelleme yazılımı (Şekil 3A) arasında bir embriyo benzer basitleştirilmiş bir 3D geometri geliştirmek.</li>
	<li>Ticari 3D bilgisayar grafik yazılımı 3D geometri negatif kalıp tasarım.</li>
	<li>1,75 mm Akrilonitril bütadien stiren filaman 3D 3D yazıcı yüklü kullanım stereolithographic (.stl) biçiminde tasarlanmış kalıp yazdırın.</li>
	<li>Kalıp döküm için silikon kauçuk elastomer bileşenleri A ve B eşit parçaya karışımı ve derhal karışımı kalıp içine dökün; 12 h (Şekil 3B) için oda sıcaklığında tedavi için döküm kalıp ayarlayın.</li>
	<li>Embriyo burulma görselleştirmek için NT sırt tarafında boyunca fiziksel model işaretleyin.</li>
	<li>Bir coverslip hangi VM veya yüzey gerilimi (şekil 3D) taklit eden 3D fiziksel modeli uygulanan kuvvet çoğaltmak için kullanın.</li>
	<li>Sert kablo fiziksel model tarafa eşit uzunlukta bir dizi ekleyin. Sonra coverslip bir dış kuvvet beyin modeli uygular, teller yere bağlıdır bir açıyla eğik haline. Dönme açısı tarafından öngörülen uzunlukta arctan her tel (Şekil 3E) orijinal uzunluğu belirler.</li>
</ol>8. kalp döngü yönünü değiştirme
<ol><li>3.1 ve 3.2 çekti bir kılcal tüp elde etmek için bölümündeki adımları izleyin.</li>
	<li>5.1 aracılığıyla 5.10 embriyo hazırlamak için adımları izleyin.</li>
	<li>Forseps bir çift filtre kağıt embriyo ventral-yan-up haline çevirmek için kullanın.</li>
	<li>Çekti kılcal tüp bir yarık splanchnopleure (SPL) membran açık kesmek için kullanın.</li>
	<li>Kılcal tüp kalbin sağ taraftan sol tarafına itmek için mekanik bir kuvvet uygulamak için kullanın.</li>
	<li>5.12 burulma değişikliği gözlemlemek için 5,15 aracılığıyla adımları izleyin.</li>
</ol>

<ol>
	<li>Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanics+of+Growth,+Remodeling,+and+Morphogenesis.">Biomechanics of Growth, Remodeling, and Morphogenesis.</a> Appl. Mech. Rev. 48, 487-545 (1995).</li><li>Wyczalkowski, M. A., Chen, Z., Filas, B. A., Varner, V. D., Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computational+models+for+mechanics+of+morphogenesis.">Computational models for mechanics of morphogenesis.</a> Birth Defects Research Part C - Embryo Today: Reviews. 96, 132-152 (2012).</li><li>Savin, T., 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=On+the+growth+and+form+of+the+gut.">On the growth and form of the gut.</a> Nature. 476, 57-62 (2011).</li><li>Gjorevski, N., Nelson, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mechanics+of+development:+Models+and+methods+for+tissue+morphogenesis.">The mechanics of development: Models and methods for tissue morphogenesis.</a> Birth Defects Research Part C - Embryo Today: Reviews. 90, 193-202 (2010).</li><li>Shyer, A. 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=Villification:+how+the+gut+gets+its+villi.">Villification: how the gut gets its villi.</a> Science. 342, 212-218 (2013).</li><li>Ambrosi, D., 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=Perspectives+on+biological+growth+and+remodeling.">Perspectives on biological growth and remodeling.</a> Journal of the Mechanics and Physics of Solids. 59, 863-883 (2011).</li><li>Chen, Z., Majidi, C., Srolovitz, D. J., Haataja, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tunable+helical+ribbons.">Tunable helical ribbons.</a> Appl. Phys. Lett. 98, (2011).</li><li>Gerbode, S. J., Puzey, J. R., McCormick, A. G., Mahadevan, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+the+cucumber+tendril+coils+and+overwinds.">How the cucumber tendril coils and overwinds.</a> Science. 337, 1087-1091 (2012).</li><li>Armon, S., Efrati, E., Kupferman, R., Sharon, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Geometry+and+mechanics+in+the+opening+of+chiral+seed+pods.">Geometry and mechanics in the opening of chiral seed pods.</a> Science. 333, 1726-1730 (2011).</li><li>Filas, B. A., 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=A+potential+role+for+differential+contractility+in+early+brain+development+and+evolution.">A potential role for differential contractility in early brain development and evolution.</a> Biomech. Model. Mechanobiol. 11, 1251-1262 (2012).</li><li>Xu, G., 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=Axons+pull+on+the+brain,+but+tension+does+not+drive+cortical+folding.">Axons pull on the brain, but tension does not drive cortical folding.</a> J. Biomech. Eng. 132, 71013 (2010).</li><li>Chen, Z., Guo, Q., Dai, E., Forsch, N., Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+the+embryonic+chick+brain+twists.">How the embryonic chick brain twists.</a> J. R. Soc. Interface. 13, (2016).</li><li>Manca, A., 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=Nerve+growth+factor+regulates+axial+rotation+during+early+stages+of+chick+embryo+development.">Nerve growth factor regulates axial rotation during early stages of chick embryo development.</a> Proc Natl Acad Sci U S A. 109, 2009-2014 (2012).</li><li>Shi, Y., Yao, J., Xu, G., Taber, L. a. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bending+of+the+looping+heart:+differential+growth+revisited.">Bending of the looping heart: differential growth revisited.</a> J. Biomech. Eng. 136, 1-15 (2014).</li><li>Shi, Y., 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=Bending+and+twisting+the+embryonic+heart:+A+computational+model+for+c-looping+based+on+realistic+geometry.">Bending and twisting the embryonic heart: A computational model for c-looping based on realistic geometry.</a> Front. Physiol. 5, (2014).</li><li>Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphomechanics:+Transforming+tubes+into+organs.">Morphomechanics: Transforming tubes into organs.</a> Current Opinion in Genetics and Development. 27, 7-13 (2014).</li><li>Hosseini, H. S., Beebe, D. C., Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+effects+of+the+surface+ectoderm+on+optic+vesicle+morphogenesis+in+the+chick+embryo.">Mechanical effects of the surface ectoderm on optic vesicle morphogenesis in the chick embryo.</a> J. Biomech. 47, 3837-3846 (2014).</li><li>Hamburger, V., Hamilton, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+series+of+normal+stages+in+the+development+of+the+chick+embryo.">A series of normal stages in the development of the chick embryo.</a> Dev. Dyn. 88, 49-92 (1951).</li><li>Shi, Y., Varner, V. D., Taber, L. a. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Why+is+cytoskeletal+contraction+required+for+cardiac+fusion+before+but+not+after+looping+begins?.">Why is cytoskeletal contraction required for cardiac fusion before but not after looping begins?.</a> Phys. Biol. 12, 16012 (2015).</li><li>Garcia, K. E., Okamoto, R. J., Bayly, P. V., Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contraction+and+stress-dependent+growth+shape+the+forebrain+of+the+early+chicken+embryo.">Contraction and stress-dependent growth shape the forebrain of the early chicken embryo.</a> J. Mech. Behav. Biomed. Mater. 65, 383-397 (2017).</li><li>Faisst, A. M., Alvarez-Bolado, G., Treichel, D., Gruss, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rotatin+is+a+novel+gene+required+for+axial+rotation+and+left-right+specification+in+mouse+embryos.">Rotatin is a novel gene required for axial rotation and left-right specification in mouse embryos.</a> Mech. Dev. 113, 15-28 (2002).</li><li>Yalcin, H. C., Shekhar, A., Rane, A. a., Butcher, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+ex-ovo+chicken+embryo+culture+system+suitable+for+imaging+and+microsurgery+applications.">An ex-ovo chicken embryo culture system suitable for imaging and microsurgery applications.</a> J. Vis. Exp. (44), (2010).</li><li>Chapman, S. C., Collignon, J., Schoenwolf, G. C., Lumsden, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+method+for+chick+whole-embryo+culture+using+a+filter+paper+carrier.">Improved method for chick whole-embryo culture using a filter paper carrier.</a> Dev. Dyn. 220, 284-289 (2001).</li><li>Camp&#224;s, O., 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=Quantifying+cell-generated+mechanical+forces+within+living+embryonic+tissues.">Quantifying cell-generated mechanical forces within living embryonic tissues.</a> Nat. Methods. 11, 183-189 (2014).</li><li>Schierenberg, E., Junkersdorf, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+eggshell+and+underlying+vitelline+membrane+for+normal+pattern+formation+in+the+early+C.+elegans+embryo.">The role of eggshell and underlying vitelline membrane for normal pattern formation in the early C. elegans embryo.</a> Roux's Arch. Dev. Biol. 202, 10-16 (1992).</li><li>Chuai, M., Weijer, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Mechanisms+Underlying+Primitive+Streak+Formation+in+the+Chick+Embryo.">The Mechanisms Underlying Primitive Streak Formation in the Chick Embryo.</a> Current Topics in Developmental Biology. 81, 135-156 (2008).</li><li>Voronov, D. A., Alford, P. W., Xu, G., Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+mechanical+forces+in+dextral+rotation+during+cardiac+looping+in+the+chick+embryo.">The role of mechanical forces in dextral rotation during cardiac looping in the chick embryo.</a> Dev. Biol. 272, 339-350 (2004).</li><li>Raya, A., Izpisua Belmonte, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unveiling+the+establishment+of+left-right+asymmetry+in+the+chick+embryo.">Unveiling the establishment of left-right asymmetry in the chick embryo.</a> Mechanisms of Development. 121, 1043-1054 (2004).</li><li>Voronov, D. A., Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+looping+in+experimental+conditions:+Effects+of+extraembryonic+forces.">Cardiac looping in experimental conditions: Effects of extraembryonic forces.</a> Dev. Dyn. 224, 413-421 (2002).</li><li>Chen, Z., Huang, G., Trase, I., Han, X., Mei, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+Self-Assembly+of+a+Strain-Engineered+Flexible+Layer:+Wrinkling,+Rolling,+and+Twisting.">Mechanical Self-Assembly of a Strain-Engineered Flexible Layer: Wrinkling, Rolling, and Twisting.</a> Phys. Rev. Appl. 5, (2016).</li><li>Manner, J., Seidl, W., Steding, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+the+cervical+flexure:+an+experimental+study+on+chick+embryos.">Formation of the cervical flexure: an experimental study on chick embryos.</a> Acta Anat. (Basel). 152, 1-10 (1995).</li><li>Ware, M., Schubert, F. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+early+axon+scaffold+in+the+rostral+brain+of+the+chick+embryo.">Development of the early axon scaffold in the rostral brain of the chick embryo.</a> J. Anat. 219, 203-216 (2011).</li><li>Ramasubramanian, A., 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=On+the+role+of+intrinsic+and+extrinsic+forces+in+early+cardiac+S-looping.">On the role of intrinsic and extrinsic forces in early cardiac S-looping.</a> Dev. Dyn. 242, 801-816 (2013).</li><li>Hoyle, C., Brown, N. a., Wolpert, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+left/right+handedness+in+the+chick+heart.">Development of left/right handedness in the chick heart.</a> Development. 115, 1071-1078 (1992).</li><li>Nerurkar, N. L., Ramasubramanian, A., Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphogenetic+adaptation+of+the+looping+embryonic+heart+to+altered+mechanical+loads.">Morphogenetic adaptation of the looping embryonic heart to altered mechanical loads.</a> Dev. Dyn. 235, 1822-1829 (2006).</li><li>Levin, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Left-right+asymmetry+and+the+chick+embryo.">Left-right asymmetry and the chick embryo.</a> Semin. Cell Dev. Biol. 9, 67-76 (1998).</li><li>Roebroek, A. 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=Failure+of+ventral+closure+and+axial+rotation+in+embryos+lacking+the+proprotein+convertase+Furin.">Failure of ventral closure and axial rotation in embryos lacking the proprotein convertase Furin.</a> Development. 125, 4863-4876 (1998).</li><li>Peebles, D. M., 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=Magnetic+resonance+proton+spectroscopy+and+diffusion+weighted+imaging+of+chick+embryo+brain+in+ovo.">Magnetic resonance proton spectroscopy and diffusion weighted imaging of chick embryo brain in ovo.</a> Dev. Brain Res. 141, 101-107 (2003).</li><li>Zhu, L., 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=Cerberus+regulates+left-right+asymmetry+of+the+embryonic+head+and+heart.">Cerberus regulates left-right asymmetry of the embryonic head and heart.</a> Curr. Biol. 9, 931-938 (1999).</li></ol>

Yazarlar hiçbir çıkar çatışmaları bildirin.

Fiziksel olaylar morfogenez26,27,28,29,30, belirli mekanik mekanizmaları, mekanik koordinasyonu ile birlikte önemli bir rol oynarken ve moleküler mekanizmalar, büyük ölçüde keşfedilmemiş kalır. Ventral bükülme ve ilkel beyin rightward burulma erken embriyonik morfogenez18,31,<su...

Modern gelişim Biyolojisi Araştırma büyük ölçüde anlayış geliştirme açısından moleküler genetik1,2,3,4,5,6 üzerinde duruluyor. , 7 , 8 , 9 , 10 , 11 , 12 , 13. fiziksel olaylar morfogenez içinde merkezi bir rol oynamak veya14,15,16,17; biyolojik nesil formu bilinen Ancak, geliştirme belirli mekanik mekanizmaları büyük ölçüde doğaçlama kalır. Ventral bükülme ve sonra Hamburger-Hamilton sahne 11 (HH 11)18 embriyonik şekle katkıda iki ana süreç ilkel beyin tüp rightward burulma19,20değiştirin. Özellikle, embriyonik beyin burulma geliştirmede temel fiziksel mekanizma tam olarak anlaşılır kalır.
Civciv embriyo embriyonik burulma-sol (sol-sağ) asimetri gelişiminde en erken morfogenetik olayları arasında yer alıyor. L-R asimetri sürecinin tedirgin, Doğum kusurları kalbin inversus, isomerismveya heterotaxia gibi21ortaya çıkar. Burada mekanik Kuvvetleri erken embriyonik beyin gelişimi sırasında karakterize için fiziksel modelleme ile ex ovo deneyler22,23 birleştiren bir iletişim kuralı mevcut. Mekanik Kuvvetleri sorumlu beyin burulma ve burulma derecesini erken geliştirme12sırasında etkileyen faktörleri belirlemek için sunulan Yöntem hedefidir. Vitelline membran (VM) embriyonun dorsal tarafında sınırlar deneysel gözlem dayalı, VM burulma gelişmekte olan beyin ikna etmek gerekli gücü sağlar olan. Bu nedenle, bu yöntemde beyin burulma üzerindeki etkilerini öğrenmek için beyin alan kaplayan VM parçası çıkardık. Ayrıca, sıvı yüzey gerilimi uygulama Yöntem VM mekanik rolü onaylamak ve daha önce yapılmamıştır beyin burulma için gerekli gücü'nün bir tahmin sağlamak için kullanılmıştır. Güçleri sırasında embriyonik morfogenez ölçme bir iştir. Özellikle, öncü bir çalışmada, Campàs ve iş24 enjekte microdroplets kullanarak hücresel stresleri ölçmek için yeni bir yöntem geliştirdi. Yine de, bu yöntem kuvvetleri hücresel düzeyde kuvvetleri, doku veya organizma düzeyinde soruşturma için bu nedenle uygulanamaz ölçmek için sınırlıydı. Bu raporda sunulan Protokolü kısmen bu boşluğu doldurmak için geliştirilmiştir.

<table border="0" cellpadding="0" cellspacing="0" width="751">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:288px;">Fertilized Specific pathogen-free White Leghorn chicken eggs</td>
			<td style="width:177px;">Charles River</td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:288px;">Optical Coherent Tomography Microscope</td>
			<td style="width:177px;">Thorlabs</td>
			<td style="width:119px;">GAN220C1</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:288px;">Silicone elastomer</td>
			<td style="width:177px;">Smooth-On, Inc.</td>
			<td style="width:119px;">EcoFlex 00-50</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Dissecting microscope</td>
			<td style="width:177px;">Leica</td>
			<td style="width:119px;">MZ8</td>
			<td></td>
		</tr>
		<tr height="39">
			<td height="39" style="height:39px;width:288px;">Dulbecco&#8217;s Modified Eagle&#8217;s Medium (DMEM)</td>
			<td style="width:177px;">Lonza</td>
			<td style="width:119px;">12-604F</td>
			<td></td>
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			<td height="21" style="height:21px;width:288px;">Antibiotics</td>
			<td style="width:177px;">Sigma</td>
			<td style="width:119px;">P4083</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Chick serum</td>
			<td style="width:177px;">Sigma</td>
			<td style="width:119px;">C5405</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Micropipette puller</td>
			<td style="width:177px;">Sutter Instrument</td>
			<td style="width:119px;">Model P-30</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Filter paper</td>
			<td style="width:177px;">Whatman</td>
			<td style="width:119px;">5202-110</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Phosphate buffered saline (PBS)</td>
			<td style="width:177px;">Corning</td>
			<td style="width:119px;">21-040-CV</td>
			<td></td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:288px;">Comsol MultiPhysics</td>
			<td style="width:177px;">Comsol</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">3D computer graphics software</td>
			<td style="width:177px;">Rhino 5</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Microscope attached with OCT</td>
			<td style="width:177px;">Nikon&#160;</td>
			<td style="width:119px;">FN1</td>
			<td></td>
		</tr>
		<tr height="18">
			<td height="18" style="height:18px;width:288px;">Digital single-lens reflex camera</td>
			<td style="width:177px;">EOS&#160;</td>
			<td style="width:119px;">Rebel T3i</td>
			<td></td>
		</tr>
	</tbody>
</table>

probing the roles of physical forces in early chick embryonic morphogenesis

Embriyonik geliştirme geleneksel biyomoleküler genetik açıdan okudu ama morfogenez mekaniğinin temel önem giderek tanınır hale. Özellikle, onlar geliştirdikçe hangi ciddi morfolojik değişiklikler geçmesi, embriyonik piliç kalp ve beyin Tüp, rol morfogenez fiziksel güçlerinin çalışmaya başbakan adayları arasında yer. İlerici ventral bükme ve borulu embriyonik piliç beyin rightward burulma organ düzeyinde sağa ve sola asimetri piliç embriyonik geliştirme erken aşamada olur. Vitelline membran (VM) embriyonun dorsal tarafında sınırlar ve burulma gelişmekte olan beyin ikna etmek gerekli gücü sağlayan karıştığı olmuştur. Burada bir arada yeni eski-ovo deneyler ve fiziksel beyin burulma mekaniği tanımlamak için modelleme mevcut. Hamburger-Hamilton aşamada 11, embriyo hasat ve kültürlü ex ovo (medya). VM çekti kılcal tüp kullanarak daha sonra kaldırılır. Sıvı düzeyini denetleyerek ve embriyo sıvı-AIR arabirimiyle tutulmasi, medya sıvı yüzey gerilimi VM mekanik rolünü değiştirmek için kullanılabilir. Mikrocerrahi deneyler de sonuç değişiklik beyin burulma sembolik bulmak için kalp konumunu değiştirmek için yapıldı. Bu iletişim kuralı sonuçlarından morfogenez sürüş mekaniğinin temel rolleri gösterilmektedir.

Bu çalışmada, HH11, embriyo VM ön taraftan torasik kivrimi kaldırıldı. Embriyo tarafından OCT sistem görüntüsü. Bu aşamada beyin tüp torsiyon (Şekil 1A) başlamamıştır. HH15-16 için inkübe sonra embriyo kaldırıldı onların VM ile düşük beyin tüp torsiyon, yaklaşık 35 yaklaşık 90 derece torsiyon gösteren embriyolar denetlemek için karşılaştırıldığında derece (Şekil 1B) sergiledi. Yüzey ge...

Watch this Scientific Journal Video about Probing the Roles of Physical Forces in Early Chick Embryonic Morphogenesis at JoVE.com

Probing the Roles of Physical Forces in Early Chick Embryonic Morphogenesis

Roller erken piliç embriyonik morfogenez fiziksel güçlerinin sondalama

Burada, yeni eski-ovo deneyleri ve morfogenetik mekaniği erken piliç embriyonik beyin burulma sırasında çalışmak için fiziksel modelleme yaklaşımlar bir dizi tanıtımı iletişim kuralı mevcut.

Embryonic development is traditionally studied from the perspective of biomolecular genetics, but the fundamental importance of mechanics in morphogenesis ...

probing-roles-physical-forces-early-chick-embryonic

Research

JoVE Journal

Bioengineering

7.2K Görüntüleme.  Dartmouth College. Burada, yeni eski-ovo deneyleri ve morfogenetik mekaniği erken piliç embriyonik beyin burulma sırasında çalışmak için fiziksel modelleme yaklaşımlar bir dizi tanıtımı iletişim kuralı mevcut.

Video: Probing the Roles of Physical Forces in Early Chick Embryonic Morphogenesis

Multiparametric Optical Mapping of the Langendorff-perfused Rabbit Heart

Optical imaging and fluorescent probes have significantly advanced research methodology in the field of cardiac electrophysiology in ways that could not have been accomplished by other approaches1. With the use of the calcium- and voltage-sensitive dyes, optical mapping allows measurement of transmembrane action potentials and calcium transients with high spatial resolution without the physical contact with the tissue. This makes measurements of the cardiac electrical activity possible under many conditions where the use of electrodes is inconvenient or impossible1. For example, optical recordings provide accurate morphological changes of membrane potential during and immediately after stimulation and defibrillation, while conventional electrode techniques suffer from stimulus-induced artifacts during and after stimuli due to electrode polarization1. 
The Langendorff-perfused rabbit heart is one of the most studied models of human heart physiology and pathophysiology. Many types of arrhythmias observed clinically could be recapitulated in the rabbit heart model. It was shown that wave patterns in the rabbit heart during ventricular arrhythmias, determined by effective size of the heart and the wavelength of reentry, are very similar to that in the human heart2. It was also shown that critical aspects of excitation-contraction (EC) coupling in rabbit myocardium, such as the relative contribution of sarcoplasmic reticulum (SR), is very similar to human EC coupling3. Here we present the basic procedures of optical mapping experiments in Langendorff-perfused rabbit hearts, including the Langendorff perfusion system setup, the optical mapping systems setup, the isolation and cannulation of the heart, perfusion and dye-staining of the heart, excitation-contraction uncoupling, and collection of optical signals. These methods could be also applied to the heart from species other than rabbit with adjustments to flow rates, optics, solutions, etc.
Two optical mapping systems are described. The panoramic mapping system is used to map the entire epicardium of the rabbit heart4-7. This system provides a global view of the evolution of reentrant circuits during arrhythmogenesis and defibrillation, and has been used to study the mechanisms of arrhythmias and antiarrhythmia therapy8,9. The dual mapping system is used to map the action potential (AP) and calcium transient (CaT) simultaneously from the same field of view10-13. This approach has enhanced our understanding of the important role of calcium in the electrical alternans and the induction of arrhythmia14-16.

This article describes the basic procedures for conducting optical mapping experiments in the Langendorff-perfused rabbit heart using the panoramic imaging system, and the dual (voltage and calcium) imaging modality.

Çok parametreli Langendorff perfüze Tavşan Kalp Optik Haritalama

Optical imaging and fluorescent probes have significantly advanced research methodology in the field of cardiac electrophysiology in ways that could not ...

Biyomühendislik

Optical Mapping of Action Potentials and Calcium Transients in the Mouse Heart

The mouse heart is a popular model for cardiovascular studies due to the existence of low cost technology for genetic engineering in this species. Cardiovascular physiological phenotyping of the mouse heart can be easily done using fluorescence imaging employing various probes for transmembrane potential (Vm), calcium transients (CaT), and other parameters. Excitation-contraction coupling is characterized by action potential and intracellular calcium dynamics; therefore, it is critically important to map both Vm and CaT simultaneously from the same location on the heart1-4. Simultaneous optical mapping from Langendorff perfused mouse hearts has the potential to elucidate mechanisms underlying heart failure, arrhythmias, metabolic disease, and other heart diseases. Visualization of activation, conduction velocity, action potential duration, and other parameters at a myriad of sites cannot be achieved from cellular level investigation but is well solved by optical mapping1,5,6. In this paper we present the instrumentation setup and experimental conditions for simultaneous optical mapping of Vm and CaT in mouse hearts with high spatio-temporal resolution using state-of-the-art CMOS imaging technology. Consistent optical recordings obtained with this method illustrate that simultaneous optical mapping of Langendorff perfused mouse hearts is both feasible and reliable.

This paper details the dissection procedure, instrumental setup, and experimental conditions during optical mapping of transmembrane potential (Vm) and intracellular calcium transient (CaT) in intact isolated Langendorff perfused mouse hearts.

Fare Kalp Aksiyon Potansiyelleri ve Kalsiyum Geçici Optik Haritalama

The mouse heart is a popular model for cardiovascular studies due to the existence of low cost technology for genetic engineering in this species. ...

Remote Magnetic Actuation of Micrometric Probes for in situ 3D Mapping of Bacterial Biofilm Physical Properties

Bacterial adhesion and growth on interfaces lead to the formation of three-dimensional heterogeneous structures so-called biofilms. The cells dwelling in these structures are held together by physical interactions mediated by a network of extracellular polymeric substances. Bacterial biofilms impact many human activities and the understanding of their properties is crucial for a better control of their development &#8212; maintenance or eradication &#8212; depending on their adverse or beneficial outcome. This paper describes a novel methodology aiming to measure in situ the local physical properties of the biofilm that had been, until now, examined only from a macroscopic and homogeneous material perspective. The experiment described here&#160;involves introducing magnetic particles into a growing biofilm to seed local probes that can be remotely actuated without disturbing the structural properties of the biofilm. Dedicated magnetic tweezers were developed to exert a defined force on each particle embedded in the biofilm. The setup is mounted on the stage of a microscope to enable the&#160;recording of time-lapse images of the particle-pulling period. The particle trajectories are then extracted from the pulling sequence and the local viscoelastic parameters are derived from each particle displacement curve, thereby providing the 3D-spatial distribution of the parameters. Gaining insights into the biofilm mechanical profile is essential from an engineer&#39;s point of view for biofilm control purposes but also from a fundamental perspective to clarify the relationship between the architectural properties and the specific biology of these structures.

Remote Magnetic Actuation of Micrometric Probes for in situ 3D Mapping of Bacterial Biofilm Physical Properties

This paper shows an original methodology based on the remote actuation of magnetic particles seeded in a bacterial biofilm and the development of dedicated magnetic tweezers to measure in situ the local mechanical properties of the complex living material built by micro-organisms at interfaces.

Için Mikrometrik Sondalar uzaktan manyetik uyarılı<em&gt; In situ</emBakteriyel biyofilm Fiziksel Özelliklerinin&gt; 3D Mapping

Bacterial adhesion and growth on interfaces lead to the formation of three-dimensional heterogeneous structures so-called biofilms. The cells dwelling in ...

Quantification of Global Diastolic Function by Kinematic Modeling-based Analysis of Transmitral Flow via the Parametrized Diastolic Filling Formalism

Quantitative cardiac function assessment remains a challenge for physiologists and clinicians.&#160;Although historically invasive methods have comprised the only means available, the development of noninvasive imaging modalities (echocardiography, MRI, CT) having high temporal and spatial resolution provide a new window for quantitative diastolic function assessment. Echocardiography is the agreed upon standard for diastolic function assessment, but indexes in current clinical use merely utilize selected features of chamber dimension (M-mode) or blood/tissue motion (Doppler) waveforms without incorporating the physiologic causal determinants of the motion itself.&#160;The recognition that all left ventricles (LV) initiate filling by serving as mechanical suction pumps allows global diastolic function to be assessed based on laws of motion that apply to all chambers. What differentiates one heart from another are the parameters of the equation of motion that governs filling. Accordingly, development of the Parametrized Diastolic Filling (PDF) formalism&#160;has shown that the entire range of clinically observed early transmitral flow (Doppler E-wave) patterns are extremely well fit by the laws of damped oscillatory motion.&#160;This permits analysis of individual E-waves in accordance with a causal mechanism (recoil-initiated suction) that yields three (numerically) unique lumped parameters whose physiologic analogues are chamber stiffness (k), viscoelasticity/relaxation (c), and load (xo).&#160;The recording of transmitral flow (Doppler E-waves) is standard practice in clinical cardiology and, therefore, the echocardiographic recording method is only briefly reviewed. Our focus is on determination of the PDF parameters from routinely recorded E-wave data.&#160;As the highlighted results indicate, once the PDF parameters have been obtained from a suitable number of load varying E-waves, the investigator is free to use the parameters or construct indexes from the parameters (such as stored energy 1/2kxo2, maximum A-V pressure gradient kxo, load independent index of diastolic function, etc.) and select the aspect of physiology or pathophysiology to be quantified.

Accurate, causality-based quantification of global diastolic function has been achieved by kinematic modeling-based analysis of transmitral flow via the Parametrized Diastolic Filling (PDF) formalism. PDF generates unique stiffness, relaxation,&#160;and load parameters and elucidates &#39;new&#39; physiology while providing sensitive and specific indexes of dysfunction.

Parametrized Diyastolik Dolum Biçimcilik yoluyla Transmitral Akışının Modellenmesi Kinematik tabanlı Analizi ile Küresel Diyastolik Fonksiyonu Kantitasyonu

Quantitative cardiac function assessment remains a challenge for physiologists and clinicians.&#160;Although historically invasive methods have comprised ...

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and dampen loads in the spine. The IVD consists of a proteoglycan-rich nucleus pulposus (NP) and a collagen-rich annulus fibrosis (AF) sandwiched by cartilaginous end-plates. Together with the adjacent vertebrae, the vertebrae-IVD structure forms a functional spine unit (FSU). These microstructures contain unique cell types as well as unique extracellular matrices. Whole organ culture of the FSU preserves the native extracellular matrix, cell differentiation phenotypes, and cellular-matrix interactions. Thus, organ culture techniques are particularly useful for investigating the complex biological mechanisms of the IVD. Here, we describe a high-throughput approach for culturing whole lumbar mouse FSUs that provides an ideal platform for studying disease mechanisms and therapies for the IVD. Furthermore, we describe several applications that utilize this organ culture method to conduct further studies including contrast-enhanced microCT imaging and three-dimensional high-resolution finite element modeling of the IVD.

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Whole organ culture of the intervertebral disc (IVD) preserves the native extracellular matrix, cell phenotypes, and cellular-matrix interactions. Here we describe an IVD culture system using mouse lumbar and caudal IVDs in their functional spinal units and several applications utilizing this system.

bir<em&gt; İn Vitro</emKemirgen İntervertebral Disk&gt; Organ Kültürü Modeli

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and ...

Improved 3D Hydrogel Cultures of Primary Glial Cells for In Vitro Modelling of Neuroinflammation

In the central nervous system, numerous acute injuries and neurodegenerative disorders, as well as implanted devices or biomaterials engineered to enhance function result in the same outcome: excess inflammation leads to gliosis, cytotoxicity, and/or formation of a glial scar that collectively exacerbate injury or prevent healthy recovery. With the intent of creating a system to model glial scar formation and study inflammatory processes, we have generated a 3D cell scaffold capable of housing primary cultured glial cells: microglia that regulate the foreign body response and initiate the inflammatory event, astrocytes that respond to form a fibrous scar, and oligodendrocytes that are typically vulnerable to inflammatory injury. The present work provides a detailed step-by-step method for the fabrication, culture, and microscopic characterization of a hyaluronic acid-based 3D hydrogel scaffold with encapsulated rat brain-derived glial cells. Further, protocols for characterization of cell encapsulation and the hydrogel scaffold by confocal immunofluorescence and scanning electron microscopy are demonstrated, as well as the capacity to modify the scaffold with bioactive substrates, with incorporation of a commercial basal lamina mixture to improved cell integration.

Improved 3D Hydrogel Cultures of Primary Glial Cells for In Vitro Modelling of Neuroinflammation

Herein, we present a protocol for the 3D culture of rat brain-derived glia cells, including astrocytes, microglia, and oligodendrocytes. We demonstrate primary cell culture, methacrylated hyaluronic acid (HAMA) hydrogel synthesis, HAMAphoto-polymerization and cell encapsulation, and sample processing for confocal and scanning electron microscopic imaging.

Geliştirilmiş 3D hidrojel Neuroinflammation Vitro modelleme için birincil gliyal hücreler kültürleri

In the central nervous system, numerous acute injuries and neurodegenerative disorders, as well as implanted devices or biomaterials engineered to enhance ...

A Tripeptide-Stabilized Nanoemulsion of Oleic Acid

We describe a method to produce a nanoemulsion composed of an oleic acids-Pt(II) core and a lysine-tyrosine-phenylalanine (KYF) coating (KYF-Pt-NE). The KYF-Pt-NE encapsulates Pt(II) at 10 wt. %, has a diameter of 107 &#177; 27 nm and a negative surface charge. The KYF-Pt-NE is stable in water and in serum, and is biologically active. The conjugation of a fluorophore to KYF allows the synthesis of a fluorescent nanoemulsion that is suitable for biological imaging. The synthesis of the nanoemulsion is performed in an aqueous environment, and the KYF-Pt-NE forms via self-assembly of a short KYF peptide and an oleic acids-platinum(II) conjugate. The self-assembly process depends on the temperature of the solution, the molar ratio of the substrates, and the flow rate of the substrate addition. Crucial steps include maintaining the optimal stirring rate during the synthesis, permitting sufficient time for self-assembly, and pre-concentrating the nanoemulsion gradually in a centrifugal concentrator.

This protocol describes an efficient method to synthesize a nanoemulsion of an oleic acids-platinum(II) conjugate stabilized with a lysine-tyrosine-phenylalanine (KYF) tripeptide. The nanoemulsion forms under mild synthetic conditions via self-assembly of the KYF and the conjugate.

Tripeptit stabilize Nanoemulsion oleik asit

We describe a method to produce a nanoemulsion composed of an oleic acids-Pt(II) core and a lysine-tyrosine-phenylalanine (KYF) coating (KYF-Pt-NE). The ...

Patterning the Geometry of Human Embryonic Stem Cell Colonies on Compliant Substrates to Control Tissue-Level Mechanics

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that correspond to primary germ layer formation during embryogenesis. Thus, these cells represent a powerful tool with which to examine the mechanisms that drive early human development. We have developed a method to culture human embryonic stem cells in confined colonies on compliant substrates that provides control over both the geometry of the colonies and their mechanical environment in order to recapitulate the physical parameters that underlie embryogenesis. The key feature of this method is the ability to generate polyacrylamide hydrogels with defined patterns of extracellular matrix ligand at the surface to promote cell attachment. This is achieved by fabricating stencils with the desired geometric patterns, using these stencils to create patterns of extracellular matrix ligand on glass coverslips, and transferring these patterns to polyacrylamide hydrogels during polymerization. This method is also compatible with traction force microscopy, allowing the user to measure and map the distribution of cell-generated forces within the confined colonies. In combination with standard biochemical assays, these measurements can be used to examine the role mechanical cues play in fate specification and morphogenesis during early human development.

Extracellular matrix ligands can be patterned onto polyacrylamide hydrogels to enable the culture of human embryonic stem cells in confined colonies on compliant substrates. This method can be combined with traction force microscopy and biochemical assays to examine the interplay between tissue geometry, cell-generated forces, and fate specification.

Doku Seviyesi Mekaniğinin Kontrol Altına Almak İçin Uyumlu Yüzeylerde İnsan Embriyonik Kök Hücre Kolonilerinin Geometrisinin Desenlemi

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that ...

Application of Atomic Force Microscopy to Detect Early Osteoarthritis

Biomechanical properties of cells and tissues not only regulate their shape and function but are also crucial for maintaining their vitality. Changes in elasticity can propagate or trigger the onset of major diseases like cancer or osteoarthritis (OA). Atomic force microscopy (AFM) has emerged as a strong tool to qualitatively and quantitatively characterize the biomechanical properties of specific biological target structures on a microscopic scale, measuring forces in a range from as small as the piconewton to the micronewton. Biomechanical properties are of special importance in musculoskeletal tissues, which are subjected to high levels of strain. OA as a degenerative disease of the cartilage results in the disruption of the pericellular matrix (PCM) and the spatial rearrangement of the chondrocytes embedded in their extracellular matrix (ECM). Disruption in PCM and ECM has been associated with changes in the biomechanical properties of cartilage. In the present study we used AFM to quantify these changes in relation to the specific spatial pattern changes of the chondrocytes. With each pattern change, significant changes in elasticity were observed for both the PCM and ECM. Measuring the local elasticity thus allows for drawing direct conclusions about the degree of local tissue degeneration in OA.

We present a method to investigate early osteoarthritic changes at the cellular level in articular cartilage by using atomic force microscopy (AFM).

Erken Osteoartrit tespit etmek için Atomik Kuvvet Mikroskobu Uygulaması

Biomechanical properties of cells and tissues not only regulate their shape and function but are also crucial for maintaining their vitality. Changes in ...

DNA Tension Probes to Map the Transient Piconewton Receptor Forces by Immune Cells

Mechanical forces transmitted at the junction between two neighboring cells and at the junction between cells and the extracellular matrix are critical for regulating many processes ranging from development to immunology. Therefore, developing the tools to study these forces at the molecular scale is critical. Our group developed a suite of molecular tension sensors to quantify and visualize the forces generated by cells and transmitted to specific ligands. The most sensitive class of molecular tension sensors are comprised of nucleic acid stem-loop hairpins. These sensors use fluorophore-quencher pairs to report on the mechanical extension and unfolding of DNA hairpins under force. One challenge with DNA hairpin tension sensors is that they are reversible with rapid hairpin refolding upon termination of the tension and thus transient forces are difficult to record. In this article, we describe the protocols for preparing DNA tension sensors that can be "locked" and prevented from refolding to enable "storing" of mechanical information. This allows for the recording of highly transient piconewton forces, which can be subsequently "erased" by the addition of complementary nucleic acids that remove the lock. This ability to toggle between real-time tension mapping and mechanical information storing reveals weak, short-lived, and less abundant forces, that are commonly employed by T cells as part of their immune functions.

This paper describes a detailed protocol for using DNA-based tension probes to image the receptor forces applied by immune cells. This approach can map receptor forces &gt;4.7pN in real-time and can integrate forces over time.

Bağışıklık Hücreleri Tarafından Geçici Piconewton Reseptör Kuvvetlerini Haritalamak için DNA Gerilim Probları

Mechanical forces transmitted at the junction between two neighboring cells and at the junction between cells and the extracellular matrix are critical ...