Name: generation and grafting of tissue-engineered vessels in a mouse model
Uploaded: 2015-03-18T14:00:00
Description: Watch this Scientific Journal Video about Generation and Grafting of Tissue-engineered Vessels in a Mouse Model at JoVE.com

This work was supported by The British Heart Foundation and The Oak Foundation.

प्रयोगशाला पशुओं के उपयोग और देखभाल के लिए संस्थागत समिति द्वारा अनुमोदित प्रोटोकॉल के अनुसार सभी पशु प्रयोगों प्रदर्शन। संस्कृति मीडिया के 1. तैयारी <ol><li> एफ-12K मध्यम, 10% भ्रूण गोजातीय सीरम (FBS) और 100 यू /...

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	<li>Kurobe, H., Maxfield, M. W., Breuer, C. K., Shinoka, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Concise+Review:+Tissue-Engineered+Vascular+Grafts+for+Cardiac+Surgery:+Past,+Present,+and+Future.">Concise Review: Tissue-Engineered Vascular Grafts for Cardiac Surgery: Past, Present, and Future.</a> Stem Cells Transl Med. 1 (7), 566-571 (2012).</li><li>Jonas, R. A., Freed, M. D., Mayer, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+follow-up+of+patients+with+synthetic+right+heart+conduits.">Long-term follow-up of patients with synthetic right heart conduits.</a> Circulation. 72, II77-II83 (1985).</li><li>Heureux, N., 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=Technology+insight:+the+evolution+of+tissue-engineered+vascular+grafts-from+research+to+clinical+practice.">Technology insight: the evolution of tissue-engineered vascular grafts-from research to clinical practice.</a> Nat Clin Pract Cardiovasc Med. 4, 389-395 (2007).</li><li>Zhang, W. J., Liu, W., Cui, L., Cao, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+engineering+of+blood+vessel.">Tissue engineering of blood vessel.</a> J Cell Mol Med. 11, 945-957 (2007).</li><li>Cearbhaill, E. 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=Response+of+mesenchymal+stem+cells+to+the+biomechanical+environment+of+the+endothelium+on+a+flexible+tubular+silicone+substrate.">Response of mesenchymal stem cells to the biomechanical environment of the endothelium on a flexible tubular silicone substrate.</a> Biomaterials. 29, 1610-1619 (2008).</li><li>Gong, Z., Niklason, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small-diameter+human+vessel+wall+engineered+from+bone+marrow-derived+mesenchymal+stem+cells+(hMSCs).">Small-diameter human vessel wall engineered from bone marrow-derived mesenchymal stem cells (hMSCs).</a> FASEB J. 22, 1635-1648 (2008).</li><li>Wong, M. 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=Over-expression+of+HSP47+augments+mouse+embryonic+stem+cell+smooth+muscle+differentiation+and+chemotaxis.">Over-expression of HSP47 augments mouse embryonic stem cell smooth muscle differentiation and chemotaxis.</a> PLoS One. 9 (1), e86118 (2014).</li><li>Park, S. W., 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=Efficient+differentiation+of+human+pluripotent+stem+cells+into+functional+CD34++progenitor+cells+by+combined+modulation+of+the+MEK/ERK+and+BMP4+signaling+pathways.">Efficient differentiation of human pluripotent stem cells into functional CD34+ progenitor cells by combined modulation of the MEK/ERK and BMP4 signaling pathways.</a> Blood. 116, 5762-5772 (2010).</li><li>Samuel, R., 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=Generation+of+functionally+competent+and+durable+engineered+blood+vessels+from+human+induced+pluripotent+stem+cells.">Generation of functionally competent and durable engineered blood vessels from human induced pluripotent stem cells.</a> Proc Natl Acad Sci USA. 110, 12774-12779 (2013).</li><li>Margariti, 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=Reprogramming+of+fibroblasts+into+endothelial+cells+capacble+of+angiogenesis+and+reendothelialization+in+tissue-engineered+vessels.">Reprogramming of fibroblasts into endothelial cells capacble of angiogenesis and reendothelialization in tissue-engineered vessels.</a> Proc Natl Acad Sci USA. 109, 13793-13798 (2012).</li><li>Karamariti, 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=Smooth+muscle+cells+differentiated+from+reprogrammed+embryonic+lung+fibroblasts+through+DKK3+signaling+are+potent+for+tissue+engineering+of+vascular+grafts.">Smooth muscle cells differentiated from reprogrammed embryonic lung fibroblasts through DKK3 signaling are potent for tissue engineering of vascular grafts.</a> Circ Res. 112, 1433-1443 (2013).</li><li>Udelsman, B., 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=Development+of+an+operator-independent+method+for+seeding+tissue-engineered+vascular+grafts.">Development of an operator-independent method for seeding tissue-engineered vascular grafts.</a> Tissue Eng Part C Methods. 17 (7), 731-736 (2011).</li><li>Cearbhaill, E. D., Murphy, M., Barry, F., McHugh, P. E., Barron, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavior+of+human+mesenchymal+stem+cells+in+fibrin-based+vascular+tissue+engineering+constructs.">Behavior of human mesenchymal stem cells in fibrin-based vascular tissue engineering constructs.</a> Ann Biomed Eng. 38 (3), 649-657 (2010).</li><li>Wong, M. 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=Macrophages+control+vascular+stem/progenitor+cell+plasticity+through+tumor+necrosis+factor-&#945;-mediated+nuclear+factor-&#954;B+activation.">Macrophages control vascular stem/progenitor cell plasticity through tumor necrosis factor-&#945;-mediated nuclear factor-&#954;B activation.</a> Arterioscler Thromb Vasc Biol. 34 (3), 635-643 (2014).</li><li>Wong, M. 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=Sirolimus+stimulates+vascular+stem/progenitor+cell+migration+and+differentiation+into+smooth+muscle+cells+via+epidermal+growth+factor+receptor/extracellular+signal-regulated+kinase/&#946;-catenin+signaling+pathway.">Sirolimus stimulates vascular stem/progenitor cell migration and differentiation into smooth muscle cells via epidermal growth factor receptor/extracellular signal-regulated kinase/&#946;-catenin signaling pathway.</a> Arterioscler Thromb Vasc Biol. 33 (10), 2397-2406 (2013).</li><li>Lee, J., Cuddihy, M. J., Kotov, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+cell+culture+matrices:+State+of+the+art.">Three-dimensional cell culture matrices: State of the art.</a> Tissue Eng Part B Rev. 14, 61-86 (2008).</li><li>Hung, H. S., Hsu, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+Advances+of+stem+cell-based+approaches+to+tissue-engineering+vascular+grafts.">Current Advances of stem cell-based approaches to tissue-engineering vascular grafts.</a> OA Tissue Engineering. 1 (1), 2 (2013).</li><li>Quint, 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=Decellularized+tissue-engineered+blood+vessel+as+an+arterial+conduit.">Decellularized tissue-engineered blood vessel as an arterial conduit.</a> Proc Natl Acad Sci USA. 108 (22), 9214-9219 (2011).</li><li>Zhang, X., Xu, Y., Thomas, V., Bellis, S. L., Vohra, Y. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineering+an+antiplatelet+adhesion+layer+on+an+electrospun+scaffold+using+porcine+endothelial+progenitor+cells.">Engineering an antiplatelet adhesion layer on an electrospun scaffold using porcine endothelial progenitor cells.</a> J Biomed Mater Res A. 97 (2), 145-151 (2011).</li><li>Hibino, N., 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=Evaluation+of+the+use+of+an+induced+puripotent+stem+cell+sheet+for+the+construction+of+tissue-engineered+vascular+grafts.">Evaluation of the use of an induced puripotent stem cell sheet for the construction of tissue-engineered vascular grafts.</a> J Thorac Cardiovasc Surg. 143 (3), 696-703 (2012).</li><li>Zhao, 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=A+novel+strategy+to+engineer+small-diameter+vascular+grafts+from+marrow-derived+mesenchymal+stem+cells.">A novel strategy to engineer small-diameter vascular grafts from marrow-derived mesenchymal stem cells.</a> Artif Organs. 36 (1), 93-101 (2012).</li><li>Tsai, 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=Contribution+of+stem+cells+to+neointimal+formation+of+decellularized+vessel+grafts+in+a+novel+mouse+model.">Contribution of stem cells to neointimal formation of decellularized vessel grafts in a novel mouse model.</a> Am J Pathol. 181 (1), 362-373 (2012).</li><li>Kasimir, M. 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=Comparison+of+different+decellularization+procedures+of+porcine+heart+valves.">Comparison of different decellularization procedures of porcine heart valves.</a> Int J Artif Organs. 26 (5), 421-427 (2003).</li><li>Stephenson, 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=Derivation+and+propagation+of+human+embryonic+stem+cell+lines+from+frozen+embryos+in+an+animal+product-free+environment.">Derivation and propagation of human embryonic stem cell lines from frozen embryos in an animal product-free environment.</a> Nature Protocols. 7, 1366-1381 (2012).</li><li>Takahashi, K., Okita, K., Nakagawa, M., Yamanaka, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+pluripotent+stem+cells+from+fibroblast+cultures.">Induction of pluripotent stem cells from fibroblast cultures.</a> Nature Protocols. 2, 3081-3089 (2007).</li><li>McCall, F. 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=Myocardial+infarction+and+intramyocardial+injection+models+in+swine.">Myocardial infarction and intramyocardial injection models in swine.</a> Nature Protocols. 7, 1479-1496 (2012).</li><li>Olausson, 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=Transplantation+of+an+allogeneic+vein+bioengineered+with+autologous+stem+cells:+a+proof-of-concept+study.">Transplantation of an allogeneic vein bioengineered with autologous stem cells: a proof-of-concept study.</a> Lancet. 380 (9838), 230-237 (2012).</li></ol>

मौजूदा प्रोटोकॉल कार्यात्मक ऊतक इंजीनियर वाहिकाओं मानव fibroblasts से PiPSC का उपयोग कर उत्पन्न किया जा सकता है, जिसमें एक ध्वनि, तेज, सरल, कुशल और प्रतिलिपि प्रस्तुत करने की रणनीति का संकेत है। इस तकनीक को निकट भ...

संवहनी नाली का निर्माण हृदय रोगों से उत्पन्न क्षतिग्रस्त और घायल जहाजों की शल्य चिकित्सा की मरम्मत के लिए एक बुनियादी रणनीति है। , Allografts, ऑटोलॉगस ऊतक (पेरीकार्डियम या saphenous नस) और xenografts 1; तिथि करने के लिए, सर्जरी में इस्तेमाल भ्रष्टाचार सामग्री biocompatible है सिंथेटिक पॉलिमर ([गोर-टेक्स ePTFE] या पॉलीथीन terephthalate [Dacron] polytetrafluoroethylene [Teflon], विस्तारित polytetrafluoroethylene) शामिल हैं। कृत्रिम ग्राफ्ट (जैसे, गोर-टेक्स और Dacron) सबसे अधिक इस्तेमाल कर रहे हैं, whilst इन सामग्रियों की संभावना एक प्रकार का रोग, कैल्शियम बयान, thrombo-embolization और संक्रमण शामिल है कि कई छोटी और लंबी अवधि जटिलताओं के कारण। साथ मौजूद जैविक grafts के साथ रोगियों thrombo-embolic की घटनाओं में कमी आई है, वे अभी भी इस तरह कड़ा हो जाना गिरावट 2 के कारण माध्यमिक भ्रष्टाचार असफलता और छोटा स्थायित्व के रूप में सीमाओं मुठभेड़। इसलिए, शल्य टी में महत्वपूर्ण सुधार के बावजूदसाल, शोधकर्ताओं और चिकित्सकों से अधिक echniques अभी भी संवहनी रोगों के लिए आदर्श नाली की पहचान करने के लिए की जरूरत के बोझ तले दब रहे हैं। हाल ही में, संवहनी ऊतक इंजीनियरिंग के अनुसंधान के क्षेत्र कोशिकाओं सफल ग्राफ्टिंग एक के लिए एक कार्यात्मक पोत के प्रतीक हैं कि एक biomimetic माहौल बनाने के उद्देश्य के साथ, biodegradable के scaffolds के रूप में शामिल कर रहे हैं, जिसमें एक अवधारणा उत्पन्न किया है। मूलरूप में, संवहनी निर्माणों की सफलता के तीन आवश्यक घटकों पर निर्भर करती है; यानी पाड़, एक endothelial सेल भीतरी परत और एक चिकनी पेशी सेल परत, देशी वाहिका संरचना करने के लिए तुलनीय यांत्रिक गुणों प्रदान करने के लिए उपयुक्त बाह्य मैट्रिक्स युक्त एक चबूतरा है, और / विनियमन की शुरुआत के लिए आवश्यक है कि सेलुलर / आणविक संकेत दे कि शामिल कोशिकाओं मरम्मत। दीर्घकालिक भ्रष्टाचार प्रत्यक्षता और नव-ऊतकों के निरंतर विकास, वें scaffolds के प्रभावी सेल बोने पर अत्यधिक निर्भर हैंereby महत्व का सेल प्रकार के निर्णय प्रतिपादन। कई रिपोर्टों छोटे व्यास नाली 3-6 विकसित करने के लिए परिपक्व endothelial और विभिन्न स्रोतों से चिकनी मांसपेशियों की कोशिकाओं के उपयोग के प्रदर्शन। होनहार हालांकि, पर्याप्त ऑटोलॉगस जहाजों की कमी परिपक्व endothelial और चिकनी मांसपेशियों की कोशिकाओं एक काफी बोझ रहना प्राप्त करने के लिए। अभी हाल ही में विभिन्न स्रोतों से स्टेम कोशिकाओं संवहनी ऊतक इंजीनियरिंग अनुप्रयोगों के लिए शोषण किया गया है। दरअसल, भ्रूण स्टेम कोशिकाओं 7 सहित स्टेम सेल प्रकार की एक किस्म, प्रेरित स्टेम कोशिकाओं (IPSCs) 8,9, PiPSC 10,11, अस्थि मज्जा व्युत्पन्न कोशिकाओं mononuclear 12, mesenchymal स्टेम सेल 13, endothelial पूर्वज कोशिकाओं और वयस्क पोत दीवार स्टेम व्युत्पन्न सेल प्रतिजन-1 (एससीए -1) + 14,15 सभी परिभाषित मीडिया के जवाब में कार्यात्मक एन्दोथेलिअल या चिकनी मांसपेशियों या तो कोशिकाओं में भेदभाव करने में सक्षम होने के लिए प्रदर्शन किया गया है स्टेम / पूर्वपुस्र्ष कोशिकाओं औरसंस्कृति की स्थिति। इसके अलावा, स्टेम कोशिकाओं की असीमित आत्म नवीकरण क्षमता उन्हें परिपक्व endothelial और केवल विकास गिरफ्तारी और वार्धक्य से गुजरने के पहले के समय की एक निश्चित संख्या के लिए विभाजित कर सकते हैं जो चिकनी मांसपेशियों की कोशिकाओं के विपरीत बेहतर उम्मीदवार बनाती है। ग्राफ्टिंग ऐसे biocompatibility, बायोमैकेनिकल गुण, और बायो़डीग्रेडेशन की दर के रूप में कई कारकों पर निर्भर करता है के लिए पाड़ सामग्री का चयन सफल ऊतक इंजीनियर पोत उत्पन्न करने के लिए। मूलरूप में, सामग्री, biodegradable होना चाहिए ग्राफ्ट के लिए scaffolds बनाने के लिए प्रयोग किया जाता है और अनावश्यक प्राप्तकर्ता प्रतिरक्षा प्रतिक्रिया माउंट नहीं होगा। इसके अतिरिक्त, यह सेल लगाव और बाद के अस्तित्व के लिए एक उपयुक्त सरंध्रता और microstructure धरना चाहिए। तिथि करने के लिए, संवहनी ऊतक इंजीनियरिंग में scaffolds के लिए इस्तेमाल सबसे आम सामग्री polyglycolic एसिड, polylactic एसिड, और पाली ε-caprolactone 16 की पॉलिमर शामिल हैं। हाल ही में, decellularized जैविक सामग्री हैयह भी कुछ सफलता के साथ लागू किया गया। कई प्रयोगशालाओं ऑटोलॉगस कोशिकाओं के साथ decellularized मानव, कुत्ते या सुअर का वाहिकाओं बोने के थक्के और intimal हाइपरप्लासिया 17-19 विरोध कि एक जैविक भ्रष्टाचार प्रदान की जाती है कि पता चला है। संवहनी ऊतक इंजीनियरिंग में अन्य रणनीतियों पाड़ समर्थन 20, 21 बिना जैसे बाह्य मैट्रिक्स प्रोटीन आधारित संवहनी ग्राफ्ट, आतंच जेल में 13 बोने कोशिकाओं और पैदा करने सेल पत्रक शामिल हैं। मौजूदा प्रोटोकॉल कार्यात्मक endothelial और चिकनी मांसपेशियों की कोशिकाओं, गंभीर संयुक्त इम्यूनो में ऊतक इंजीनियर वाहिकाओं के एक कार्यात्मक PiPSC व्युत्पन्न नाड़ी कोशिकाओं बंदरगाह के लिए एक decellularized पोत पाड़ से मिलकर बायोरिएक्टर, और ग्राफ्टिंग की पीढ़ी (SCID में मानव PiPSC के भेदभाव को दर्शाता है ) चूहों। PiPSC इन कोशिकाओं को चूहों में ट्यूमर फार्म या नैतिक बढ़ा नहीं है क्योंकि पोत grafts के ऊतक इंजीनियरिंग के लिए उपयोग करने के लिए एक इष्टतम सेल प्रकार के होते हैं औरallo-प्रतिरक्षा प्रतिक्रिया। इसके अलावा, हम पिप्स-endothelial कोशिकाओं और पिप्स-चिकनी मांसपेशियों की कोशिकाओं को उत्पन्न करने के लिए रणनीति कुशल और 10,11 प्रतिलिपि प्रस्तुत करने योग्य है कि पता चला है। इसके बाद, हम इस प्रकार ग्राफ्टिंग और अस्तित्व प्रभावकारिता को बढ़ाने, बारीकी से एक देशी पोत के भीतर मौजूद है कि मैट्रिक्स प्रोटीन की नकल करने PiPSC व्युत्पन्न नाड़ी कोशिकाओं के बोने के लिए एक decellularized पोत बनाया गया है। इसके अलावा, पूर्व PiPSC बोने के लिए जहाजों की decellularization ऐसे मैक्रोफेज के रूप में प्रतिरक्षा सेल प्रकार से मुहिम शुरू की भड़काऊ प्रतिक्रियाओं की घटना को रोकता है। इससे भी महत्वपूर्ण बात, इस प्रोटोकॉल केवल मनुष्य में अनुवाद के लिए संवहनी नाली का वादा उत्पन्न करने के लिए एक पद्धति का प्रतिनिधित्व नहीं करता है, लेकिन यह भी अध्ययन और माउस मॉडल के माध्यम से संवहनी ऊतक पुनर्जनन को नियंत्रित करने वाले आणविक तंत्र को समझने के मूल्यवान साधन प्रदान करता है।

<table border="0" cellpadding="0" cellspacing="0" >
	<tbody>
		<tr >
			<td >Human Fibroblasts CCL-153</td>
			<td >ATCC</td>
			<td >CCL-153</td>
			<td>Prenatal human embryonic fibroblasts</td>
		</tr>
		<tr >
			<td >ATCC F-12K Medium (Kaighn&#39;s Modification of Ham&#39;s F-12 Medium)</td>
			<td >ATCC</td>
			<td >30-2004</td>
			<td></td>
		</tr>
		<tr >
			<td >Fetal Bovine Serum</td>
			<td >ATCC</td>
			<td >30-2020</td>
			<td></td>
		</tr>
		<tr >
			<td >Knockout DMEM medium optimized for embryonic stem cells</td>
			<td >Life technologies (Gibco)</td>
			<td >12660-012</td>
			<td></td>
		</tr>
		<tr >
			<td >Knockout Serum Replacement</td>
			<td >Life technologies (Invitrogen)</td>
			<td >10828-028</td>
			<td></td>
		</tr>
		<tr >
			<td >Human Basic FGF-2&#160;</td>
			<td >Miltenyi Biotech</td>
			<td >130-093-837</td>
			<td></td>
		</tr>
		<tr >
			<td >alpha-MEM medium</td>
			<td >Life technologies (Invitrogen)</td>
			<td >32571093</td>
			<td></td>
		</tr>
		<tr >
			<td >Human PDGF</td>
			<td >R&#38;D System</td>
			<td >120-HD-001</td>
			<td></td>
		</tr>
		<tr >
			<td >Gelatin Solution 2%</td>
			<td >Sigma</td>
			<td >G1393</td>
			<td></td>
		</tr>
		<tr >
			<td >Plasmid 20866: pCAG2LMKOSimO (SOX2, OCT4, KLF4, C-MYC)</td>
			<td >Addgene</td>
			<td >20866</td>
			<td></td>
		</tr>
		<tr >
			<td >&#160;PvuI Restriction Enzyme</td>
			<td >New England Biolabs</td>
			<td >RO150S</td>
			<td></td>
		</tr>
		<tr >
			<td >SureClean Plus</td>
			<td >Bioline</td>
			<td >BIO-37047</td>
			<td></td>
		</tr>
		<tr >
			<td >Nucelofection Kit (NHDF Kit)</td>
			<td >LONZA</td>
			<td >VPD-1001</td>
			<td></td>
		</tr>
		<tr >
			<td >Neomycin</td>
			<td >SIGMA</td>
			<td >G418</td>
			<td>Selection of&#160;</td>
		</tr>
		<tr >
			<td >KL 1500 LCD, Illumination for Stereo Microscopy</td>
			<td >SCHOTT</td>
			<td >KL 1500 LCD</td>
			<td>Cold light illumination for stereo microscopy</td>
		</tr>
		<tr >
			<td >Nikon Zoom Steromicroscope SMZ800</td>
			<td >Nikon</td>
			<td >SMZ800</td>
			<td></td>
		</tr>
		<tr >
			<td >Heparin sodium salt</td>
			<td >Sigma</td>
			<td >H3393</td>
			<td></td>
		</tr>
		<tr >
			<td >10% SDS Stock Solution Molecular Biology Reagent</td>
			<td >Severn Biotech</td>
			<td >CAS 151-21-3</td>
			<td></td>
		</tr>
		<tr >
			<td >Dulbecco&#39;s Phosphate Buffered Saline</td>
			<td >Sigma</td>
			<td >D8537</td>
			<td></td>
		</tr>
		<tr >
			<td >Matrigel (10mg/ml)</td>
			<td >BD</td>
			<td >A6661</td>
			<td></td>
		</tr>
		<tr >
			<td >Shaker IKA Vibrax with Shaking platform VX 7&#160;</td>
			<td >Jepson Bolton&#39;s, Janke&#38;Kunkel</td>
			<td >S32-102</td>
			<td></td>
		</tr>
		<tr >
			<td >Masterflex L/S Digital Pump Drive</td>
			<td >Cole-Parmer</td>
			<td >WZ-07523-80</td>
			<td></td>
		</tr>
		<tr >
			<td >Masterflex L/S 6-channel, 6-roller cartridge pump head</td>
			<td >Cole-Parmer</td>
			<td >EW-07519-15</td>
			<td></td>
		</tr>
		<tr >
			<td >Masterflex L/S large cartridges for pump head</td>
			<td >Cole-Parmer</td>
			<td >EW-07519-75</td>
			<td></td>
		</tr>
		<tr >
			<td >Masterflex platinum-cured silicone pump tubing, L/S 14, 25 ft</td>
			<td >Cole-Parmer&#160;</td>
			<td >WZ-96410-14</td>
			<td >Tubing goes through the peristaltic pump</td>
		</tr>
		<tr >
			<td >0.5mm ID, 0.8 mm OD Silicone Tubing</td>
			<td >SILEX</td>
			<td >N/A</td>
			<td>Tubings connect incubation chamber, media reservoir and compliance chamber&#160;</td>
		</tr>
		<tr >
			<td >Fitting Reducer 0.5 to 1.6, natural Polypropyline</td>
			<td >Ibidi</td>
			<td >10829</td>
			<td>Adapter connect above two types of tubings</td>
		</tr>
		<tr >
			<td >1/32&#34; Tubing, ID 0.01&#34; (250&#181;m) Material: PEEK</td>
			<td >LabSmith</td>
			<td >T-132-010P</td>
			<td>Tubing through the incubation chamber wall which connects the graft with outside tubing</td>
		</tr>
		<tr >
			<td >One-Piece Fittings&#160;</td>
			<td >LabSmith</td>
			<td >T-132-100</td>
			<td>Fix the above tubings through the incubation chamber wall</td>
		</tr>
		<tr >
			<td >Nylon tubes (OD 0.9mm, ID 0.75mm)&#160;</td>
			<td >Smiths Medical</td>
			<td >N/A</td>
			<td>Tubings insert into two ends of the aorta graft</td>
		</tr>
		<tr >
			<td >NOD.CB17-Prkdcscid/NcrCrl mouse</td>
			<td >Charles River</td>
			<td ></td>
			<td ></td>
		</tr>
		<tr >
			<td >Surgical sutures, 8-0&#160; silk</td>
			<td >ETHICON</td>
			<td >W819</td>
			<td ></td>
		</tr>
		<tr >
			<td >Hypnorm</td>
			<td >Vetapharm</td>
			<td >Vm21757/4000</td>
			<td >Neuroleptanalgesic for use in mice</td>
		</tr>
		<tr >
			<td >Hypnovel (Midazolam)</td>
			<td >Roche</td>
			<td >59467-70-8</td>
			<td >Induction of anaesthesia</td>
		</tr>
		<tr >
			<td >Dissecting microscope</td>
			<td >Carl Zeiss</td>
			<td >Stemi 2000</td>
			<td ></td>
		</tr>
		<tr >
			<td >Nylon Tubing</td>
			<td >Portex LTD</td>
			<td >800/200/100/200</td>
			<td >0.65 mm in diameter and 1 mm in length; to make artery cuff</td>
		</tr>
		<tr >
			<td >Electrocoagulator</td>
			<td >Martin&#160;</td>
			<td >SN 54.131</td>
			<td >Ligation of artery branches on aorta</td>
		</tr>
		<tr >
			<td >Bipolar micro hemostat forceps</td>
			<td >Martin</td>
			<td >80-91-12-04</td>
			<td >Fixation of vessel ends</td>
		</tr>
		<tr >
			<td >Vessel Dilator</td>
			<td >S&#38;T</td>
			<td >JFX-7</td>
			<td ></td>
		</tr>
		<tr >
			<td >Vessel Dilator</td>
			<td >S&#38;T</td>
			<td >JFL-3dZ</td>
			<td ></td>
		</tr>
		<tr >
			<td >Vessel Dilator</td>
			<td >S&#38;T</td>
			<td >D-5aZ</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mini applier&#160;</td>
			<td >AESCULAP</td>
			<td >FE572K</td>
			<td ></td>
		</tr>
		<tr >
			<td >Micro hemostats clips</td>
			<td >AESCULAP</td>
			<td >FE720K</td>
			<td ></td>
		</tr>
		<tr >
			<td >Surgical sutures, 6-0 VICRYL</td>
			<td >ETHICON</td>
			<td >V489</td>
			<td ></td>
		</tr>
	</tbody>
</table>

generation and grafting of tissue-engineered vessels in a mouse model

The construction of vascular conduits is a fundamental strategy for surgical repair of damaged and injured vessels resulting from cardiovascular diseases. The current protocol presents an efficient and reproducible strategy in which functional tissue engineered vessel grafts can be generated using partially induced pluripotent stem cell (PiPSC) from human fibroblasts. We designed a decellularized vessel scaffold bioreactor, which closely mimics the matrix protein structure and blood flow that exists within a native vessel, for seeding of PiPSC-endothelial cells or smooth muscle cells prior to grafting into mice. This approach was demonstrated to be advantageous because immune-deficient mice engrafted with the PiPSC-derived grafts presented with markedly increased survival rate 3 weeks after surgery. This protocol represents a valuable tool for regenerative medicine, tissue engineering and potentially patient-specific cell-therapy in the near future.

PiPSC के सफल पीढ़ी 4 प्रतिलेखन कारक, OCT4, Sox2, KLF4 और सी-MYC (OSKM) ले जाने के एक linearized pCAG2LMKOSimO प्लाज्मिड के साथ मानव fibroblasts nucleofecting के बाद चार दिनों की पुष्टि की थी। PiPSC fibroblasts (2A चित्रा) की तुलना में जब एक स्पष्ट रूप से अलग फेनोटा?...

Watch this Scientific Journal Video about Generation and Grafting of Tissue-engineered Vessels in a Mouse Model at JoVE.com

Generation and Grafting of Tissue-engineered Vessels in a Mouse Model

यहाँ, हम डबल बोने आंशिक रूप से प्रेरित स्टेम सेल से चूहों में कलम बांधने का काम के लिए कार्य कर रहे हैं कि ऊतक इंजीनियर पोत ग्राफ्ट उत्पन्न करने के लिए एक प्रोटोकॉल प्रस्तुत (PiPSC) - एक decellularized पोत पाड़ बायोरिएक्टर पर व्युत्पन्न endothelial कोशिकाओं - चिकनी मांसपेशियों की कोशिकाओं और PiPSC निकाली गई।

एक माउस मॉडल में ऊतक इंजीनियर वेसल्स का सृजन और कलम बांधने का काम

The construction of vascular conduits is a fundamental strategy for surgical repair of damaged and injured vessels resulting from cardiovascular diseases. ...

generation-and-grafting-of-tissue-engineered-vessels-in-a-mouse-model

Research

JoVE Journal

Bioengineering

Protocol for Relative Hydrodynamic Assessment of Tri-leaflet Polymer Valves

Limitations of currently available prosthetic valves, xenografts, and homografts have prompted a recent resurgence of developments in the area of tri-leaflet polymer valve prostheses. However, identification of a protocol for initial assessment of polymer valve hydrodynamic functionality is paramount during the early stages of the design process. Traditional in vitro pulse duplicator systems are not configured to accommodate flexible tri-leaflet materials; in addition, assessment of polymer valve functionality needs to be made in a relative context to native and prosthetic heart valves under identical test conditions so that variability in measurements from different instruments can be avoided. Accordingly, we conducted hydrodynamic assessment of i) native (n = 4, mean diameter, D = 20 mm), ii) bi-leaflet mechanical (n= 2, D = 23 mm) and iii) polymer valves (n = 5, D = 22 mm) via the use of a commercially available pulse duplicator system (ViVitro Labs Inc, Victoria, BC) that was modified to accommodate tri-leaflet valve geometries. Tri-leaflet silicone valves developed at the University of Florida comprised the polymer valve group. A mixture in the ratio of 35:65 glycerin to water was used to mimic blood physical properties. Instantaneous flow rate was measured at the interface of the left ventricle and aortic units while pressure was recorded at the ventricular and aortic positions. Bi-leaflet and native valve data from the literature was used to validate flow and pressure readings. The following hydrodynamic metrics were reported: forward flow pressure drop, aortic root mean square forward flow rate, aortic closing, leakage&#160;and regurgitant volume, transaortic closing, leakage, and total energy losses. Representative results indicated that hydrodynamic metrics from the three valve groups could be successfully obtained by incorporating a custom-built assembly into a commercially available pulse duplicator system and subsequently, objectively compared to provide insights on functional aspects of polymer valve design.

There has been renewed interest in developing polymer valves. Here, the objectives are to demonstrate the feasibility of modifying a commercial pulse duplicator to accommodate tri-leaflet geometries and to define a protocol to present polymer valve hydrodynamic data in comparison to native and prosthetic valve data collected under near-identical conditions.

सप्ताह में तीन पत्रक पॉलिमर वाल्व के सापेक्ष द्रव्यगतिकी आकलन के लिए प्रोटोकॉल

Limitations of currently available prosthetic valves, xenografts, and homografts have prompted a recent resurgence of developments in the area of ...

Preparation of Light-responsive Membranes by a Combined Surface Grafting and Postmodification Process

In order to modify the surface tension of commercial available track-edged polymer membranes, a procedure of surface-initiated polymerization is presented. The polymerization from the membrane surface is induced by plasma treatment of the membrane, followed by reacting the membrane surface with a methanolic solution of 2-hydroxyethyl methacrylate (HEMA). Special attention is given to the process parameters for the plasma treatment prior to the polymerization on the surface. For example, the influence of the plasma-treatment on different types of membranes (e.g.&#160;polyester, polycarbonate, polyvinylidene fluoride) is studied. Furthermore, the time-dependent stability of the surface-grafted membranes is shown by contact angle measurements. When grafting poly(2-hydroxyethyl methacrylate) (PHEMA) in this way, the surface can be further modified by esterification of the alcohol moiety of the polymer with a carboxylic acid function of the desired substance. These reactions can therefore be used for the functionalization of the membrane surface. For example, the surface tension of the membrane can be changed or a desired functionality as the presented light-responsiveness can be inserted. This is demonstrated by reacting PHEMA with a carboxylic acid functionalized spirobenzopyran unit which leads to a light-responsive membrane. The choice of solvent plays a major role in the postmodification step and is discussed in more detail in this paper. The permeability measurements of such functionalized membranes are performed using a Franz cell with an external light source. By changing the wavelength of the light from the visible to the UV-range, a change of permeability of aqueous caffeine solutions is observed.

A plasma-induced polymerization procedure is described for the surface-initiated polymerization on polymer membranes. Further postmodification of the grafted polymer with photochromic substances is presented with a protocol of conducting permeability measurements of light-responsive membranes.

एक संयुक्त भूतल कलम बांधने का काम और Postmodification प्रक्रिया से प्रकाश उत्तरदायी झिल्ली की तैयारी

In order to modify the surface tension of commercial available track-edged polymer membranes, a procedure of surface-initiated polymerization is ...

Surgical Technique for the Implantation of Tissue Engineered Vascular Grafts and Subsequent In Vivo Monitoring

The development of Tissue Engineered Vessels (TEVs) is advanced by the ability to routinely and effectively implant TEVs (4-5 mm in diameter) into a large animal model. A step by-step protocol for inter-positional placement of the TEV and real-time digital assessment of the TEV and native carotid arteries is described here. In vivo monitoring is made possible by the implantation of flow probes, catheters and ultrasonic crystals (capable of recording dynamic diameter changes of implanted TEVs and native carotid arteries) at the time of surgery. Once implanted, researchers can calculate arterial blood flow patterns, invasive blood pressure and artery diameter yielding parameters such as pulse wave velocity, augmentation index, pulse pressures and compliance. Data acquisition is accomplished using a single computer program for analysis throughout the duration of the experiment. Such invaluable data provides insight into TEV matrix remodeling, its resemblance to native/sham controls and overall TEV performance in vivo.

Surgical Technique for the Implantation of Tissue Engineered Vascular Grafts and Subsequent In Vivo Monitoring

A step-by-step protocol for the inter-positional placement of Tissue Engineered Vessels (TEVs) into the carotid artery of a sheep using end-to-end anastomosis and real-time digital assessment in vivo until animal sacrifice.

ऊतक इंजीनियर संवहनी grafts और इसके बाद के आरोपण के लिए शल्य चिकित्सा तकनीक<em&gt; Vivo</em&gt; निगरानी

The development of Tissue Engineered Vessels (TEVs) is advanced by the ability to routinely and effectively implant TEVs (4-5 mm in diameter) into a large ...

Generation of a Three-dimensional Full Thickness Skin Equivalent and Automated Wounding

In vitro models are a cost effective and ethical alternative to study cutaneous wound healing processes. Moreover, by using human cells, these models reflect the human wound situation better than animal models. Although two-dimensional models are widely used to investigate processes such as cellular migration and proliferation, models that are more complex are required to gain a deeper knowledge about wound healing. Besides a suitable model system, the generation of precise and reproducible wounds is crucial to ensure comparable results between different test runs. In this study, the generation of a three-dimensional full thickness skin equivalent to study wound healing is shown. The dermal part of the models is comprised of human dermal fibroblast embedded in a rat-tail collagen type I hydrogel. Following the inoculation with human epidermal keratinocytes and consequent culture at the air-liquid interface, a multilayered epidermis is formed on top of the models. To study the wound healing process, we additionally developed an automated wounding device, which generates standardized wounds in a sterile atmosphere.

The goal of this protocol is to build up a three-dimensional full thickness skin equivalent, which resembles natural skin. With a specifically constructed automated wounding device, precise and reproducible wounds can be generated under maintenance of sterility.

एक तीन आयामी पूर्ण मोटाई त्वचा की पीढ़ी के बराबर है और स्वचालित लोग घायल हो गए

In vitro models are a cost effective and ethical alternative to study cutaneous wound healing processes. Moreover, by using human cells, these models ...

Production, Characterization and Potential Uses of a 3D Tissue-engineered Human Esophageal Mucosal Model

The incidence of both esophageal adenocarcinoma and its precursor, Barrett&#8217;s Metaplasia, are rising rapidly in the western world. Furthermore esophageal adenocarcinoma generally has a poor prognosis, with little improvement in survival rates in recent years. These are difficult conditions to study and there has been a lack of suitable experimental platforms to investigate disorders of the esophageal mucosa.
A model of the human esophageal mucosa has been developed in the MacNeil laboratory which, unlike conventional 2D cell culture systems, recapitulates the cell-cell and cell-matrix interactions present in vivo and produces a mature, stratified epithelium similar to that of the normal human esophagus. Briefly, the model utilizes non-transformed normal primary human esophageal fibroblasts and epithelial cells grown within a porcine-derived acellular esophageal scaffold. Immunohistochemical characterization of this model by CK4, CK14, Ki67 and involucrin staining demonstrates appropriate recapitulation of the histology of the normal human esophageal mucosa.
This model provides a robust, biologically relevant experimental model of the human esophageal mucosa. It can easily be manipulated to investigate a number of research questions including the effectiveness of pharmacological agents and the impact of exposure to environmental factors such as alcohol, toxins, high temperature or gastro-esophageal refluxate components. The model also facilitates extended culture periods not achievable with conventional 2D cell culture, enabling, inter alia, the study of the impact of repeated exposure of a mature epithelium to the agent of interest for up to 20 days. Furthermore, a variety of cell lines, such as those derived from esophageal tumors or Barrett&#8217;s Metaplasia, can be incorporated into the model to investigate processes such as tumor invasion and drug responsiveness in a more biologically relevant environment.

This manuscript describes the production, characterization and potential uses of a tissue engineered 3D esophageal construct prepared from normal primary human esophageal fibroblast and squamous epithelial cells seeded within a de-cellularized porcine scaffold. The results demonstrate the formation of a mature stratified epithelium similar to the normal human esophagus.

एक 3 डी ऊतक इंजीनियर मानव इसोफेजियल mucosal मॉडल का उत्पादन, लक्षण और क्षमता का उपयोग करता

The incidence of both esophageal adenocarcinoma and its precursor, Barrett&#8217;s Metaplasia, are rising rapidly in the western world. Furthermore ...

A Combined 3D Tissue Engineered In Vitro/In Silico Lung Tumor Model for Predicting Drug Effectiveness in Specific Mutational Backgrounds

In the present study, we combined an in vitro 3D lung tumor model with an in silico model to optimize predictions of drug response based on a specific mutational background. The model is generated on a decellularized porcine scaffold that reproduces tissue-specific characteristics regarding extracellular matrix composition and architecture including the basement membrane. We standardized a protocol that allows artificial tumor tissue generation within 14 days including three days of drug treatment. Our article provides several detailed descriptions of 3D read-out screening techniques like the determination of the proliferation index Ki67 staining&#39;s, apoptosis from supernatants by M30-ELISA and assessment of epithelial to mesenchymal transition (EMT), which are helpful tools for evaluating the effectiveness of therapeutic compounds. We could show compared to 2D culture a reduction of proliferation in our 3D tumor model that is related to the clinical situation. Despite of this lower proliferation, the model predicted EGFR-targeted drug responses correctly according to the biomarker status as shown by comparison of the lung carcinoma cell lines HCC827 (EGFR -mutated, KRAS wild-type) and A549 (EGFR wild-type, KRAS-mutated) treated with the tyrosine-kinase inhibitor (TKI) gefitinib. To investigate drug responses of more advanced tumor cells, we induced EMT by long-term treatment with TGF-beta-1 as assessed by vimentin/pan-cytokeratin immunofluorescence staining. A flow-bioreactor was employed to adjust culture to physiological conditions, which improved tissue generation. Furthermore, we show the integration of drug responses upon gefitinib treatment or TGF-beta-1 stimulation - apoptosis, proliferation index and EMT - into a Boolean in silico model. Additionally, we explain how drug responses of tumor cells with a specific mutational background and counterstrategies against resistance can be predicted. We are confident that our 3D in vitro approach especially with its in silico expansion provides an additional value for preclinical drug testing in more realistic conditions than in 2D cell culture.

A Combined 3D Tissue Engineered In Vitro/In Silico Lung Tumor Model for Predicting Drug Effectiveness in Specific Mutational Backgrounds

We present a three-dimensional (3D) lung cancer model based on a biological collagen scaffold to study sensitivity towards non-small-cell-lung-cancer-(NSCLC)-targeted therapies. We demonstrate different read-out techniques to determine the proliferation index, apoptosis and epithelial-mesenchymal transition (EMT) status. Collected data are integrated into an in silico model for prediction of drug sensitivity.

एक संयुक्त 3 डी ऊतक इंजीनियर<em&gt; इन विट्रो</em&gt; /<em&gt; सिलिको</emविशिष्ट mutational पृष्ठभूमि में ड्रग प्रभावशीलता की भविष्यवाणी के लिए&gt; फेफड़े ट्यूमर मॉडल

In the present study, we combined an in vitro 3D lung tumor model with an in silico model to optimize predictions of drug response based on a specific ...

Applications of In Vivo Functional Testing of the Rat Tibialis Anterior for Evaluating Tissue Engineered Skeletal Muscle Repair

Despite the regenerative capacity of skeletal muscle, permanent functional and/or cosmetic deficits (e.g., volumetric muscle loss (VML) resulting from traumatic injury, disease and various congenital, genetic and acquired conditions are quite common. Tissue engineering and regenerative medicine technologies have enormous potential to provide a therapeutic solution. However, utilization of biologically relevant animal models in combination with longitudinal assessments of pertinent functional measures are critical to the development of improved regenerative therapeutics for treatment of VML-like injuries. In that regard, a commercial muscle lever system can be used to measure length, tension, force and velocity parameters in skeletal muscle. We used this system, in conjunction with a high power, bi-phase stimulator, to measure in vivo force production in response to activation of the anterior crural compartment of the rat hindlimb. We have previously used this equipment to assess the functional impact of VML injury on the tibialis anterior (TA) muscle, as well as the extent of functional recovery following treatment of the injured TA muscle with our tissue engineered muscle repair (TEMR) technology. For such studies, the left foot of an anaesthetized rat is securely anchored to a footplate linked to a servomotor, and the common peroneal nerve is stimulated by two percutaneous needle electrodes to elicit muscle contraction and dorsiflexion of the foot. The peroneal nerve stimulation-induced muscle contraction is measured over a range of stimulation frequencies (1-200 Hz), to ensure an eventual plateau in force production that allows for an accurate determination of peak tetanic force. In addition to evaluation of the extent of VML injury as well as the degree of functional recovery following treatment, this methodology can be easily applied to study diverse aspects of muscle physiology and pathophysiology. Such an approach should assist with the more rational development of improved therapeutics for muscle repair and regeneration.

Applications of In Vivo Functional Testing of the Rat Tibialis Anterior for Evaluating Tissue Engineered Skeletal Muscle Repair

We describe an in vivo protocol to measure dorsiflexion of the foot following stimulation of the peroneal nerve and contraction of the anterior crural compartment of the rat hindlimb. Such measurements are an indispensable translational tool for evaluating skeletal muscle pathology and tissue engineering approaches to muscle repair and regeneration.

के आवेदन<em&gt; Vivo</em&gt; ऊतक मूल्यांकन के लिए चूहा tibialis पूर्वकाल के कार्यात्मक परीक्षण इंजीनियर कंकाल की मांसपेशी की मरम्मत

Despite the regenerative capacity of skeletal muscle, permanent functional and/or cosmetic deficits (e.g., volumetric muscle loss (VML) resulting from ...

Three-dimensional Tissue Engineered Aligned Astrocyte Networks to Recapitulate Developmental Mechanisms and Facilitate Nervous System Regeneration

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to replace lost neurons and regenerate axonal pathways. However, during nervous system development, neuronal migration and axonal extension often occur along pathways formed by other cells, referred to as &#34;living scaffolds&#34;. Seeking to emulate these mechanisms and to design a strategy that circumvents the inhibitory environment of the CNS, this manuscript presents a protocol to fabricate tissue engineered astrocyte-based &#34;living scaffolds&#34;. To create these constructs, we employed a novel biomaterial encasement scheme to induce astrocytes to self-assemble into dense three-dimensional bundles of bipolar longitudinally-aligned somata and processes. First, hollow hydrogel micro-columns were assembled, and the inner lumen was coated with collagen extracellular-matrix. Dissociated cerebral cortical astrocytes were then delivered into the lumen of the cylindrical micro-column and, at a critical inner diameter of &#60;350 &#181;m, spontaneously self-aligned and contracted to produce long fiber-like cables consisting of dense bundles of astrocyte processes and collagen fibrils measuring &#60;150 &#181;m in diameter yet extending several cm in length. These engineered living scaffolds exhibited &#62;97% cell viability and were virtually exclusively comprised of astrocytes expressing a combination of the intermediate filament proteins glial-fibrillary acidic protein (GFAP), vimentin, and nestin. These aligned astrocyte networks were found to provide a permissive substrate for neuronal attachment and aligned neurite extension. Moreover, these constructs maintain integrity and alignment when extracted from the hydrogel encasement, making them suitable for CNS implantation. These preformed constructs structurally emulate key cytoarchitectural elements of naturally occurring glial-based &#34;living scaffolds&#34; in vivo. As such, these engineered living scaffolds may serve as test-beds to study neurodevelopmental mechanisms in vitro or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding following CNS degeneration in vivo.

We showcase the development of self-assembled, three-dimensional bundles of longitudinally aligned astrocytic somata and processes within a novel biomaterial encasement. These engineered &#34;living scaffolds&#34;, exhibiting micron-scale diameter yet extending centimeters in length, may serve as test-beds to study neurodevelopmental mechanisms or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding.

तीन आयामी ऊतक दोहराऊंगा विकासात्मक तंत्र के लिए गठबंधन Astrocyte नेटवर्क इंजीनियर और तंत्रिका तंत्र पुनर्जनन की सुविधा

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to ...

A Novel Tenorrhaphy Suture Technique with Tissue Engineered Collagen Graft to Repair Large Tendon Defects

Surgical management of large tendon defects with tendon grafts is challenging, as there are a finite number of sites where donors can be readily identified and used. Currently, this gap is filled with tendon auto-, allo-, xeno-, or artificial grafts, but clinical methods to secure them are not necessarily translatable to animals because of the scale. In order to evaluate new biomaterials or study a tendon graft made up of collagen type 1, we have developed a modified suture technique to help maintain the engineered tendon in alignment with the tendon ends. Mechanical properties of these grafts are inferior to the native tendon. To incorporate engineered tendon into clinically relevant models of loaded repair, a strategy was adopted to offload the tissue engineered tendon graft and allow for the maturation and integration of the engineered tendon in vivo until a mechanically sound neo-tendon was formed. We describe this technique using incorporation of the collagen type 1 tissue engineered tendon construct.

In this paper, we present an in vitro and in situ protocol to repair a tendon gap of up to 1.5 cm by filling it with engineered collagen graft. This was performed by developing a modified suture technique to take the mechanical load until the graft matures into the host tissue.

बड़े टेंडन दोषों की मरम्मत के लिए ऊतक इंजीनियर कोलेजन ग्राफ्ट के साथ एक उपन्यास टेनोरहैफी सीवन तकनीक

Surgical management of large tendon defects with tendon grafts is challenging, as there are a finite number of sites where donors can be readily ...

Seeding and Implantation of a Biosynthetic Tissue-engineered Tracheal Graft in a Mouse Model

Treatment options for congenital or secondary long segment tracheal defects have historically been limited due to an inability to replace functional tissue. Tissue engineering holds great promise as a potential solution with its ability to integrate cells and signaling molecules into a 3-dimensional scaffold. Recent work with tissue engineered tracheal grafts (TETGs) has seen some success but their translation has been limited by graft stenosis, graft collapse, and delayed epithelialization. In order to investigate the mechanisms driving these issues, we have developed a mouse model for tissue engineered tracheal graft implantation. TETGs were constructed using electrospun polymers polyethylene terephthalate (PET) and polyurethane (PU) in a mixture of PET and PU (20:80 percent weight). Scaffolds were then seeded using bone marrow mononuclear cells isolated from 6-8 week-old C57BL/6 mice by gradient centrifugation. Ten million cells per graft were seeded onto the lumen of the scaffold and allowed to incubate overnight before implantation between the third and seventh tracheal rings. These grafts were able to recapitulate the findings of stenosis and delayed epithelialization as demonstrated by histological analysis and lack of Keratin 5 and Keratin 14 basal epithelial cells on immunofluorescence. This model will serve as a tool for investigating cellular and molecular mechanisms involved in host remodeling.

Graft stenosis poses a critical obstacle in tissue engineered airway replacement. To investigate cellular mechanisms underlying stenosis, we utilize a murine model of tissue engineered tracheal replacement with seeded bone marrow mononuclear cells (BM-MNC). Here, we detail our protocol, including scaffold manufacturing, BM-MNC isolation, graft seeding, and implantation.

एक माउस मॉडल में एक जैव सिंथेटिक ऊतक इंजीनियर Tracheal भ्रष्टाचार के बोने और आरोपण

Treatment options for congenital or secondary long segment tracheal defects have historically been limited due to an inability to replace functional ...