Yeni Teşvik Ödülü, Thrasher Araştırma Fonu ve Boston Çocuk Hastanesi&#39;nden Kalp İletim Fonu katkı; Bu çalışma Ulusal Sağlık Enstitüsü&#39;nün araştırma hibeleri (HL088206 HL068915) tarafından desteklenmektedir.

Bölüm 1: döküm kalıpları inşa birleştirin. <ol><li> Yarıya silikon tüp (VWR) ve 3 cm uzunluğunda parçalar halinde kesmek için jilet kullanın. </li><li> Hortumun her iki ucundaki iç implant dereceli RTV silikon yapıştırıcı (Rhodia) bir damla yerleştirin. </li><li> Silikon yapıştırıcı açılan küçük bir parça polyester örgü (1 cm x 1 cm) (McMaster-Carr) hızlı bir şekilde yerleştirin ve hortumun ucu ile aynı hizaya getirin. Bu yapı eki için biraz yükseltilmiş ve düz bir yüzey sağlayacaktır. Diğer ucu için tekrarlayın. </li><li> Kalıp, 3 gün boyunca oda sıcaklığında kurumaya bırakın. Bu aslında tek olarak, bir defada 20 ila 30 kalıp yapmak için yararlı olur. </li><li> Yapıştırıcı tamamen kuruduktan sonra ihtiyaç duydukları kadar,% 70 etanol ile dolu bir beher bu kalıpları saklamak. Bu adım kalıpları sterilize yardımcı olacak ve bitmiş ürün Şekil 1&#39;de gösterilmiştir. </li></ol> Bölüm 2: myoblast hücre izolasyonu için Hazırlık <ol><li> 250 1 mg Laminin (Sigma) sulandırınız ml 0.22 mikron filtre ile sterilize edilmiş fosfat tamponlu salin (PBS) ve% 1 penisilin / Streptomisin (Invitrogen) ve% 1 Fungizone (Invitrogen) içeren. </li><li> Coat 150 mm 4 seyreltilmiş Laminin çözüm adımı 1.1 mL ve birincil iskelet matür kaplama önce en az 4 saat süreyle 37 º C&#39;de inkübe doku kültürü levhalar (BD Falcon). </li><li> (% 20 FBS (Atlanta Biyolojik), 5 ng / L temel Fibroblast Büyüme Faktörü (Promega), 1% Penisilin / Streptomisin (Invitrogen), ve% 1 Fungizone Ham F-10 Besin Karışım (Sigma) karıştırma myoblast orta olun Invitrogen). </li><li> 1 g, 100 mL 2.4 U / ml Dispase-2 (Roche) ~ 295 U / mg kollajenaz 2 (Worthington) eriterek iskelet kas sindirim çözüm hazırlayın. 0.037 g CaCl 2 ekleyin ve iyice karıştırın. -20 ° C&#39;de 10 ml şırınga ve mağaza alikotları takılan bir 0,2 mikron filtre disk kullanarak sindirim tampon sterilize filtreleme 37 ° C myoblast medya ile birlikte doku sindirim için gerekli olan miktar koyun. </li></ol> Bölüm 3: iskelet kas Myoblast izolasyonu <ol><li> Forseps ve küçük bir makas kullanarak, omurilik boyunca arka dilimleme cilt ve fasya tabakaları geri soyma ve sonra kasların eksize ölü yenidoğan Lewis sıçan paraspinal kaslar çıkarın. </li><li> Bir doku kültürü kaputu, buz üzerinde 1X Hanks Dengeli Tuz Çözeltisi 40 ml (HBSS) (Invitrogen) ile dolu bir 50 ml konik tüp (BD Falcon) eksize kasları yerleştirin. Kas şeritleri tüp altına yerleşmek ve dikkatli bir kültür kapağı (Baker), steril bir Pasteur pipet yardımıyla vakum emme sıvı ve kan kalıntılarının en çıkarmak için izin verin. </li><li> Hasat kas adet 150 mm kültür çanak üzerine dökün ve mümkün olduğunca emme ile kalan sıvı kadar kaldırın. 2 tek kenarlı Jilet kullanmak kalın bir macun doku kıyma. Hamurun üzerine dökün ve önceden ısıtılmış sindirim çözüm karışımı 10 ml pipet kullanarak yeni bir 50 ml tüp transferi. Enzimatik sindirim sırasında, doku bazen telsiz Pipet-Aid (Drummond) takılan 10 ml pipetle (köpüren olmadan) triturated konumundadır. Yine, aşırı sıvı doku yerleşmek ve kaldırmak için izin verir. </li><li> Sallanan bir platform üzerinde tüp yerleştirin ve yaklaşık 30 dakika süreyle 37 º C&#39;de sindirimi. </li><li> Kas sıvılaştırılmış sonra, 600 xg (Beckman GP) 10 dakika boyunca oda sıcaklığında 70 mikron hücre süzgecinden (BD Falcon) ve santrifüj yoluyla çözüm geçmek. Pasteur, pipet ve emme ile sıvı kadar mümkün olduğunca kaldırın ve tekrar süspansiyon, 10 ml sıcak myoblast orta pelet. </li><li> Ön plakası 15 dakika boyunca bir kaplanmamış 150 mm doku kültürü plaka hücreleri fibroblastlar kaldırmanıza yardımcı olmak için. </li><li> Henüz laminin kaplı Kültür varlıkları bağlı ve her 1 ila 2 sıçan yavrular için bir tabak olacak şekilde seyreltik hücreleri aktarın. 37 ° C ile% 5 CO 2 nemlendirilmiş bir inkübatör seti plaka koyun. </li></ol> Bölüm 4: Döküm mühendislik doku yapıları (5 ml) <ol><li> 1 ila 2 gün sonra, 10 inkübatör 150 mm myoblast doku kültürü tabak kaldırmak için, 37 ° C 1X PBS ile iki kez yıkayın ve sıcak,% 0.05 tripsin-EDTA 4 mL her plaka ekleyin. 5 dakika süreyle inkübatör plakaları geri dön. </li><li> Kültür kaputun içindeki plakalar müstakil matür Hasat ve 50 ml tüp içinde sıvı (BD Falcon) toplayabilir. 10 ml myoblast orta plakaların yıkayın ve santrifüj tüpüne hücreleri birleştirmek için kullanın. Pelet 600 xg (Beckman GP) 10 dakika oda sıcaklığında hücreleri ve adım 3.5 &#39;te açıklandığı gibi aşırı sıvı kaldırmak. </li><li> Buz üzerinde myoblast orta ve yerin 1.6 mL myoblast hücreleri tekrar </li><li> Forseps kullanarak dikkatli bir şekilde adım 1,5 &#39;dan 4 yapı kalıpları kaldırmak ve onları 1X PBS ile iki kez yıkayın. 6-iyi bir doku cu her kalıp yerleştirmeden önce Pasteur pipeti ile PBS tüm izlerini kapalı vakum emmelture plaka (BD Falcon). </li><li> Buz üzerinde yapı hazırlanması için gerekli diğer reaktifler (10X Ham F10, antibiyotikler, tip 1 kollajen [3,9 mg / ml] [6] ve Matrigel ™) toplayın ve 37 º C&#39;de myoblast medya tutmak 500 mcL 10X Ham F10, 100 mcL Penisilin / Streptomisin, 100 mcL Fungizone, 1.6 ml kollajen, ve 15 ml konik tüp içinde 750 mcL Matrigel ™ birleştirdik. 10 sn buz üzerinde 10 Mini-Vortexer (VWR) ve yeri için çözüm karıştırın. </li><li> Sonra, adım 3.5 80 NaHCO 3 mcL ve 3.3 adım myoblast süspansiyon karışıma ekleyin. 10 sn vorteksleyin tüm karışım ve baloncuklar çözüm temizlemek için birkaç dakika süreyle buz kovası tüp. </li><li> 10 ml pipet kullanarak katılaşmaya başlamadan önce kalıplar içine karışımı dikkatlice döküm. Her kalıp viskoz sıvı yaklaşık 1 ml yapacak. Bu işlem sırasında hava kabarcıkları tanıtan önlemek için deneyin. </li><li> Inkübatör dökme yapıları içeren plaka dikkatlice aktarın. ~ 30 dakika sonra, inkübatör katılaşmış yapıları kaldırmak ve doku inşa kapsayacak şekilde dikkatle, her bir kuyunun myoblast orta eklemek. Inkübatör (Şekil 2) plaka dönün. </li></ol> Bölüm 5: Temsilci sonuçları Bu protokol düzgün çalıştırıldığında, myoblast içeren doku inşa in vivo implantasyon için hazırdır (küf kaldırılır gibi) ya da 2 gün sonra in vitro analizler Daha fazla bilgi için . <img src="/files/ftp_upload/1137/Figure1.jpg" alt="" /> Şekil 1. tamamlanan yapı kalıp örnekleri (Adım 1.5 &#39;e bakınız). <img src="/files/ftp_upload/1137/Figure2.jpg" alt="" width="400" height="321" /> Şekil 2 katılaşmış myoblast içeren doku [1] inşa. <img src="/files/ftp_upload/1137/Figure3.jpg" alt="" /> Şekil 3: H &amp; E myoblast içeren doku lekeli bölümleri oluşturun . &quot;A&quot; uzunlamasına bir bölümü gösteriyor ve &quot;B&quot; bir kesit göstermektedir.

<ol>
	<li>Choi, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+conduction+through+engineered+tissue.">Cardiac conduction through engineered tissue.</a> Am J Pathol. 169 (1), 72-85 (2006).</li><li>Rando, T. A., Blau, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Primary+mouse+myoblast+purification,+characterization,+and+transplantation+for+cell-mediated+gene+therapy.">Primary mouse myoblast purification, characterization, and transplantation for cell-mediated gene therapy.</a> J Cell Biol. 125 (6), 1275-1287 (1994).</li><li>Blau, H. M., Webster, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+characterization+of+human+muscle+cells.">Isolation and characterization of human muscle cells.</a> Proc Natl Acad Sci U S A. 78 (9), 5623-5627 (1981).</li><li>Powell, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue-engineered+human+bioartificial+muscles+expressing+a+foreign+recombinant+protein+for+gene+therapy.">Tissue-engineered human bioartificial muscles expressing a foreign recombinant protein for gene therapy.</a> Hum Gene Ther. 10 (4), 565-577 (1999).</li><li>Vandenburgh, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue-engineered+skeletal+muscle+organoids+for+reversible+gene+therapy.">Tissue-engineered skeletal muscle organoids for reversible gene therapy.</a> Hum Gene Ther. 7 (17), 2195-2200 (1996).</li><li>Gallop, P. M., Seifter, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+Properties+of+Soluble+Collagens.">Preparation and Properties of Soluble Collagens.</a> Methods in Enzymology. 6, 635-641 (1963).</li></ol>

Boston Çocuk Hastanesi&#39;nden Kurumsal Hayvan Bakım ve Kullanım Kurulu tarafından belirlenen kurallara ve yönetmeliklere uygun olarak hayvanlar üzerinde deneyler yapıldı.

Olacağı doku inşa döküm kalıpları, herhangi bir şekil ve boyut olarak yapılabilir, ancak, ek, en az iki puan olması gerekir. Aksi takdirde, matriks ve hücrelerin küresel bir yapı oluştururlar ve hücreleri ölür. Bu protokolde, polyester mesh kullanımı bu amaç için bir tarif, ama biz de başarıyla kullanılan paslanmaz çelik hasır. Açıkçası, büyük kalıplar daha fazla hücre ve diğer malzemelerle daha büyük bir hacim gerektirir. Kalıpları yaparken, kullanılan silikon yapıştırıcı mi...

<table><tbody><tr><td>Silicone tubing</td><td>VWR international</td><td>60985-724</td><td></td></tr><tr><td>Silicone adhesive</td><td>Rhodia Silicones</td><td>MED ADH 4300 RTV</td><td></td></tr><tr><td>Polyester Mesh</td><td>McMaster-Carr</td><td>93185T17</td><td></td></tr><tr><td>Laminin</td><td>Sigma-Aldrich</td><td>L2020</td><td></td></tr><tr><td>Nutrient Mixture F-10 HAM</td><td>Sigma-Aldrich</td><td>N6908</td><td></td></tr><tr><td>Fetal Bovine Serum</td><td>Atlanta Biologicals</td><td>S11550</td><td></td></tr><tr><td>Penicillin/Streptomycin</td><td>Invitrogen</td><td>15140</td><td></td></tr><tr><td>Fungizone</td><td>Invitrogen</td><td>15290-018</td><td></td></tr><tr><td>Dispase-2</td><td>Roche Group</td><td>10295825001</td><td></td></tr><tr><td>Collagenase 2</td><td>Worthington Biochemical</td><td>46H8863</td><td></td></tr><tr><td>Basic Fibroblast Growth Factor</td><td>Promega Corp.</td><td>G5071</td><td></td></tr><tr><td>150 mm tissue culture dishes</td><td>BD Biosciences</td><td>353025</td><td></td></tr><tr><td>0.05% (1X) Trypsin-EDTA</td><td>GIBCO, by Life Technologies</td><td>25300</td><td></td></tr><tr><td>1X Hanks Balanced Salt Solution</td><td>Invitrogen</td><td>14170-112</td><td></td></tr><tr><td>7.5% NaHCO&lt;sub&gt;3&lt;/sub&gt;</td><td>GIBCO, by Life Technologies</td><td>25080-094</td><td></td></tr><tr><td>70 &amp;mu;m cell strainer</td><td>BD Biosciences</td><td>352350</td><td></td></tr><tr><td>6-well plates</td><td>BD Biosciences</td><td>353046</td><td></td></tr><tr><td>50 mL Conical Vial</td><td>BD Biosciences</td><td>352098</td><td></td></tr><tr><td>15 mL Conical Vial</td><td>BD Biosciences</td><td>352099</td><td></td></tr><tr><td>0.2 &amp;mu;m filter</td><td>Nalge Nunc international</td><td>194-2520</td><td></td></tr></tbody></table>

fabrication of myogenic engineered tissue constructs

Elektronik kalp pili olduğu gerçeğine rağmen yaşam tasarruf tıbbi cihazlar, pediatrik hastalarda uzun süreli performans bir çocuğun, küçük boyutları ve onların kaçınılmaz büyüme dayattığı kısıtlamaları sorunlu nedeniyle olabilir. Sonuç olarak, kalp ritmi bozuklukları olan pediatrik hastalar için özel olarak tasarlanmış yenilikçi tedaviler için gerçek bir ihtiyaç vardır. Önerdiğimiz içeren bir kolajen bazlı matris oluşan iletken bir biyolojik alternatif hücreler daha iyi, daha büyümeye uyum tekrarlayan ameliyatlar için ihtiyacını azaltır ve büyük ölçüde bu hastalar için yaşam kalitesini artırmak autologously-türetilmiştir. Bu çalışmada, biz moda hidrojel bir matriks içinde kalbin üst ve alt odacıkları arasındaki bir elektrik iletkeni olarak hizmet verecek bir cerrahi implant doku birincil iskelet myoblast hücre kültürleri birleştiren bir yapı için bir prosedür açıklanmaktadır. Sonuçta, biz, tam kalp bloğu olan çocuklar atriyoventriküler elektrik iletim geri yüklemek için bu tür mühendislik doku kullanarak tahmin ediyoruz. Bunun görünümünde matür, yenidoğan Lewis sıçan ve plaka kurulan protokolleri değiştirilmiş bir sürümünü kullanarak laminin kaplı doku kültürü yemekleri üzerine iskelet kasları izole<sup&gt; [2, 3]</sup&gt;. 1-2 gün sonra, kültür hücreleri, antibiyotik ile tip 1 kollajen, Matrigel ™, ve NaHCO toplanır ve karıştırılır<sub&gt; 3</sub&gt;. Sonucu hemen hemen her şekil ve büyüklükte bir kalıp içine dökme edilebilir bir viskoz, düzgün bir çözüm<sup&gt; [1, 4, 5]</sup&gt;. Doku yapıları, tip 1 kollajen standart prosedürler kullanarak fetal kuzu derisi izole istihdam<sup&gt; [6]</sup&gt;. Sonra doku, 37 katılaşmış ° C, yapı suya kadar kültür ortamı dikkatle plaka eklenir. Mühendislik doku daha sonra bunun için hazır olduğunu ve bu noktada, 2 gün daha dehidratasyon ile daha fazla yoğunlaşmaya izin verilir<em&gt; In vitro</em&gt; Değerlendirme veya cerrahi implantasyon.

Watch this Scientific Journal Video about Fabrication of Myogenic Engineered Tissue Constructs at JoVE.com

Fabrication of Myogenic Engineered Tissue Constructs

Burada, kolajen doku, iskelet matür içeren yapıları imalatı göstermektedir. Bu 3-D mühendislik yapıları dokuların değiştirmek veya onarmak için kullanılan olabilir<em&gt; In vivo</em&gt;. Bizim amaçlarımız için, atriyoventriküler tam kalp bloğu tamiri için bir elektrik iletkeni olarak tasarladık<sup&gt; [1]</sup&gt;.

MİYOJEN Engineered Doku oluşturur imalatı

Despite the fact that electronic pacemakers are life-saving medical devices, their long-term performance in pediatric patients can be problematic owing to ...

fabrication-of-myogenic-engineered-tissue-constructs

Universidad de Cartagena UDEC

Research

JoVE Journal

Biology

10.4K Görüntüleme.  Children's Hospital Boston and Harvard Medical School. Burada, kolajen doku, iskelet matür içeren yapıları imalatı göstermektedir. Bu 3-D mühendislik yapıları dokuların değiştirmek veya onarmak için kullanılan olabilir In vivo. Bizim amaçlarımız için, atriyoventriküler tam kalp bloğu tamiri için bir elektrik iletkeni olarak tasarladık [1].

Video: Fabrication of Myogenic Engineered Tissue Constructs

Fabrication of Biologically Derived Injectable Materials for Myocardial Tissue Engineering

This protocol provides methods for the preparation of an injectable extracellular matrix (ECM) gel for myocardial tissue engineering applications. Briefly, decellularized tissue is lyophilized, milled, enzymatically digested, and then brought to physiological pH. The lyophilization removes all water content from the tissue, resulting in dry ECM that can be ground into a fine powder with a small mill. After milling, the ECM powder is digested with pepsin to form an injectable matrix. After adjustment to pH 7.4, the liquid matrix material can be injected into the myocardium. Results of previous characterization assays have shown that matrix gels produced from decellularized pericardial and myocardial tissue retain native ECM components, including diverse proteins, peptides and glycosaminoglycans. Given the use of this material for tissue engineering, in vivo characterization is especially useful; here, a method for performing an intramural injection into the left ventricular (LV) free wall is presented as a means of analyzing the host response to the matrix gel in a small animal model. Access to the chest cavity is gained through the diaphragm and the injection is made slightly above the apex in the LV free wall. The biologically derived scaffold can be visualized by biotin-labeling before injection and then staining tissue sections with a horse radish peroxidase-conjugated neutravidin and visualizing via diaminobenzidine (DAB) staining. Analysis of the injection region can also be done with histological and immunohistochemical staining. In this way, the previously examined pericardial and myocardial matrix gels were shown to form fibrous, porous networks and promote vessel formation within the injection region.

Methods for preparing an injectable matrix gel from decellularized tissue and injecting it into rat myocardium in vivo are described.

Miyokard Doku Mühendisliği Biyolojik Türetilmiş Enjektabl Malzeme imalatı

This protocol provides methods for the preparation of an injectable extracellular matrix (ECM) gel for myocardial tissue engineering applications.  ...

Biyomühendislik

Engineering Skeletal Muscle Tissues from Murine Myoblast Progenitor Cells and Application of Electrical Stimulation

Engineered muscle tissues can be used for several different purposes, which include the production of tissues for use as a disease model in vitro, e.g. to study pressure ulcers, for regenerative medicine and as a meat alternative 1. The first reported 3D muscle constructs have been made many years ago and pioneers in the field are Vandenburgh and colleagues 2,3. Advances made in muscle tissue engineering are not only the result from the vast gain in knowledge of biochemical factors, stem cells and progenitor cells, but are in particular based on insights gained by researchers that physical factors play essential roles in the control of cell behavior and tissue development. State-of-the-art engineered muscle constructs currently consist of cell-populated hydrogel constructs. In our lab these generally consist of murine myoblast progenitor cells, isolated from murine hind limb muscles or a murine myoblast cell line C2C12, mixed with a mixture of collagen/Matrigel and plated between two anchoring points, mimicking the muscle ligaments. Other cells may be considered as well, e.g. alternative cell lines such as L6 rat myoblasts 4, neonatal muscle derived progenitor cells 5, cells derived from adult muscle tissues from other species such as human 6 or even induced pluripotent stem cells (iPS cells) 7. Cell contractility causes alignment of the cells along the long axis of the construct 8,9 and differentiation of the muscle progenitor cells after approximately one week of culture. Moreover, the application of electrical stimulation can enhance the process of differentiation to some extent 8. Because of its limited size (8 x 2 x 0.5 mm) the complete tissue can be analyzed using confocal microscopy to monitor e.g. viability, differentiation and cell alignment. Depending on the specific application the requirements for the engineered muscle tissue will vary; e.g. use for regenerative medicine requires the up scaling of tissue size and vascularization, while to serve as a meat alternative translation to other species is necessary.

Engineered muscle tissue has great potential in regenerative medicine, as disease model and also as an alternative source for meat. Here we describe the engineering of a muscle construct, in this case from mouse myoblast progenitor cells, and the stimulation by electrical pulses.

Elektrik Stimülasyonu murin myoblast Progenitör Hücreler ve Uygulama Mühendislik İskelet Kası Dokular

Engineered muscle tissues can be used for several different purposes, which include the production of tissues for use as a disease model in vitro, e.g. to ...

Generation of Aligned Functional Myocardial Tissue Through Microcontact Printing

Advanced heart failure represents a major unmet clinical challenge, arising from the loss of viable and/or fully functional cardiac muscle cells. Despite optimum drug therapy, heart failure represents a leading cause of mortality and morbidity in the developed world. A major challenge in drug development is the identification of cellular assays that accurately recapitulate normal and diseased human myocardial physiology in vitro. Likewise, the major challenges in regenerative cardiac biology revolve around the identification and isolation of patient-specific cardiac progenitors in clinically relevant quantities. These cells have to then be assembled into functional tissue that resembles the native heart tissue architecture. Microcontact printing allows for the creation of precise micropatterned protein shapes that resemble structural organization of the heart, thus providing geometric cues to control cell adhesion spatially. Herein we describe our approach for the isolation of highly purified myocardial cells from pluripotent stem cells differentiating in vitro, the generation of cell growth surfaces micropatterned with extracellular matrix proteins, and the assembly of the stem cell-derived cardiac muscle cells into anisotropic myocardial tissue.

The generation of aligned myocardial tissue is a key requirement for adapting the recent advances in stem cell biology to clinically useful purposes. Herein we describe a microcontact printing approach for the precise control of cell shape and function. Using highly purified populations of embryonic stem cell derived cardiac progenitors, we then generate anisotropic functional myocardial tissue.

Mikrokontak baskı sayesinde Bağlantısızlar Fonksiyonel Miyokard Doku Üretimi

Advanced heart failure represents a major unmet clinical challenge,  arising from the loss of viable and/or fully functional cardiac muscle  cells. ...

Engineering Fibrin-based Tissue Constructs from Myofibroblasts and Application of Constraints and Strain to Induce Cell and Collagen Reorganization

Collagen content and organization in developing collagenous tissues can be influenced by local tissue strains and tissue constraint. Tissue engineers aim to use these principles to create tissues with predefined collagen architectures. A full understanding of the exact underlying processes of collagen remodeling to control the final tissue architecture, however, is lacking. In particular, little is known about the (re)orientation of collagen fibers in response to changes in tissue mechanical loading conditions. We developed an in&#160;vitro model system, consisting of biaxially-constrained myofibroblast-seeded fibrin constructs, to further elucidate collagen (re)orientation in response to i) reverting biaxial to uniaxial static loading conditions and ii) cyclic uniaxial loading of the biaxially-constrained constructs before and after a change in loading direction, with use of the Flexcell FX4000T loading device. Time-lapse confocal imaging is used to visualize collagen (re)orientation in a nondestructive manner.
Cell and collagen organization in the constructs can be visualized in real-time, and an internal reference system allows us to relocate cells and collagen structures for time-lapse analysis. Various aspects of the model system can be adjusted, like cell source or use of healthy and diseased cells. Additives can be used to further elucidate mechanisms underlying collagen remodeling, by for example adding MMPs or blocking integrins. Shape and size of the construct can be easily adapted to specific needs, resulting in a highly tunable model system to study cell and collagen (re)organization.

This model system starts from a myofibroblast-populated fibrin gel that can be used to study endogenous collagen (re)organization real-time in a nondestructive manner. The model system is very tunable, as it can be used with different cell sources, medium additives, and can be adapted easily to specific needs.

Mühendislik Fibrin tabanlı Doku miyofibroblastlar ve Kısıtlar Uygulamasından Yapıları ve Hücre ve Kollajen (Re) Organizasyon tetikleyebilecek süzün

Collagen content and organization in developing collagenous tissues can be influenced by local tissue strains and tissue constraint. Tissue engineers aim ...

Tissue Engineering: Construction of a Multicellular 3D Scaffold for the Delivery of Layered Cell Sheets

Many tissues, such as the adult human hearts, are unable to adequately regenerate after damage.2,3 Strategies in tissue engineering propose innovations to assist the body in recovery and repair. For example, TE approaches may be able to attenuate heart remodeling after myocardial infarction (MI) and possibly increase total heart function to a near normal pre-MI level.4 As with any functional tissue, successful regeneration of cardiac tissue involves the proper delivery of multiple cell types with environmental cues favoring integration and survival of the implanted cell/tissue graft. Engineered tissues should address multiple parameters including: soluble signals, cell-to-cell interactions, and matrix materials evaluated as delivery vehicles, their effects on cell survival, material strength, and facilitation of cell-to-tissue organization. Studies employing the direct injection of graft cells only ignore these essential elements.2,5,6 A tissue design combining these ingredients has yet to be developed. Here, we present an example of integrated designs using layering of patterned cell sheets with two distinct types of biological-derived materials containing the target organ cell type and endothelial cells for enhancing new vessels formation in the &#8220;tissue&#8221;. Although these studies focus on the generation of heart-like tissue, this tissue design can be applied to many organs other than heart with minimal design and material changes, and is meant to be an off-the-shelf product for regenerative therapies. The protocol contains five detailed steps. A temperature sensitive Poly(N-isopropylacrylamide) (pNIPAAM) is used to coat tissue culture dishes. Then, tissue specific cells are cultured on the surface of the coated plates/micropattern surfaces to form cell sheets with strong lateral adhesions. Thirdly, a base matrix is created for the tissue by combining porous matrix with neovascular permissive hydrogels and endothelial cells. Finally, the cell sheets are lifted from the pNIPAAM coated dishes and transferred to the base element, making the complete construct.

For creation of highly organized structures of complex tissue, one must assemble multiple material and cell types into an integrated composite. This combinatorial design incorporates organ-specific layered cell sheets with two distinct biologically-derived materials containing a strong fibrous matrix base, and endothelial cells for enhancing new vessels formation.

Doku Mühendisliği: Katmanlı Hücre Sheets teslimi için bir Multisellüler 3D İskele İnşaatı

Many tissues, such as the adult human hearts, are unable to adequately regenerate after damage.2,3 Strategies in tissue engineering propose innovations to ...

Engineering 3D Cellularized Collagen Gels for Vascular Tissue Regeneration

Synthetic materials are known to initiate clinical complications such as inflammation, stenosis, and infections when implanted as vascular substitutes. Collagen has been extensively used for a wide range of biomedical applications and is considered a valid alternative to synthetic materials due to its inherent biocompatibility (i.e., low antigenicity, inflammation, and cytotoxic responses). However, the limited mechanical properties and the related low hand-ability of collagen gels have hampered their use as scaffold materials for vascular tissue engineering. Therefore, the rationale behind this work was first to engineer cellularized collagen gels into a tubular-shaped geometry and second to enhance smooth muscle cells driven reorganization of collagen matrix to obtain tissues stiff enough to be handled.
The strategy described here is based on the direct assembling of collagen and smooth muscle cells (construct) in a 3D cylindrical geometry with the use of a molding technique. This process requires a maturation period, during which the constructs are cultured in a bioreactor under static conditions (without applied external dynamic mechanical constraints) for 1 or 2 weeks. The &#8220;static bioreactor&#8221; provides a monitored and controlled sterile environment (pH, temperature, gas exchange, nutrient supply and waste removal) to the constructs. During culture period, thickness measurements were performed to evaluate the cells-driven remodeling of the collagen matrix, and glucose consumption and lactate production rates were measured to monitor the cells metabolic activity. Finally, mechanical and viscoelastic properties were assessed for the resulting tubular constructs. To this end, specific protocols and a focused know-how (manipulation, gripping, working in hydrated environment, and so on) were developed to characterize the engineered tissues.

In this work, we present a technique for the rapid fabrication of living vascular tissues by direct culturing of collagen, smooth muscle cells and endothelial cells. In addition, a new protocol for the mechanical characterization of engineered vascular tissues is described.

Vasküler Doku Rejenerasyon için Mühendislik 3D cellularized Kollajen jeller

Synthetic materials are known to initiate clinical complications such as inflammation, stenosis, and infections when implanted as vascular substitutes. ...

Engineered Vascularized Muscle Flap

One of the main factors limiting the thickness of a tissue construct and its consequential viability and applicability in vivo, is the control of oxygen supply to the cell microenvironment, as passive diffusion is limited to a very thin layer. Although various materials have been described to restore the integrity of full-thickness defects of the abdominal wall, no material has yet proved to be optimal, due to low graft vascularization, tissue rejection, infection, or inadequate mechanical properties. This protocol describes a means of engineering a fully vascularized flap, with a thickness relevant for muscle tissue reconstruction. Cell-embedded poly L-lactic acid/poly lactic-co-glycolic acid constructs are implanted around the mouse femoral artery and vein and maintained in vivo for a period of one or two weeks. The vascularized graft is then transferred as a flap towards a full thickness defect made in the abdomen. This technique replaces the need for autologous tissue sacrifications and may enable the use of in vitro engineered vascularized flaps in many surgical applications.

To date, thick tissue defects are typically reconstructed by applying autologous tissue flaps or engineered tissues. In this protocol, we present a new method for engineering vascularized tissue flap bearing an autologous pedicle, to serve as a substitute to autologous flaps.

Engineered Vaskülarize Muscle Flap

One of the main factors limiting the thickness of a tissue construct and its consequential viability and applicability in vivo, is the control of oxygen ...

Fabrication of Custom Agarose Wells for Cell Seeding and Tissue Ring Self-assembly Using 3D-Printed Molds

Engineered tissues are being used clinically for tissue repair and replacement, and are being developed as tools for drug screening and human disease modeling. Self-assembled tissues offer advantages over scaffold-based tissue engineering, such as enhanced matrix deposition, strength, and function. However, there are few available methods for fabricating 3D tissues without seeding cells on or within a supporting scaffold. Previously, we developed a system for fabricating self-assembled tissue rings by seeding cells into non-adhesive agarose wells. A polydimethylsiloxane (PDMS) negative was first cast in a machined polycarbonate mold, and then agarose was gelled in the PDMS negative to create ring-shaped cell seeding wells. However, the versatility of this approach was limited by the resolution of the tools available for machining the polycarbonate mold. Here, we demonstrate that 3D-printed plastic can be used as an alternative to machined polycarbonate for fabricating PDMS negatives. The 3D-printed mold and revised mold design is simpler to use, inexpensive to produce, and requires significantly less agarose and PDMS per cell seeding well. We have demonstrated that the resulting agarose wells can be used to create self-assembled tissue rings with customized diameters from a variety of different cell types. Rings can then be used for mechanical, functional, and histological analysis, or for fabricating larger and more complex tubular tissues.

This protocol describes a platform for fabricating self-assembled tissue rings in variable sizes using a customized 3D-printed plastic mold. PDMS negatives are cured in the 3D-printed mold; then agarose is cast in the cured PDMS negatives. Cells are seeded into the resulting agarose wells where they aggregate into tissue rings.

Hücre tohum için özel özel Wells ve kendinden montajlı 3D baskı kalıpları kullanarak doku yüzük imalatı

Engineered tissues are being used clinically for tissue repair and replacement, and are being developed as tools for drug screening and human disease ...

Assessing Functional Metrics of Skeletal Muscle Health in Human Skeletal Muscle Microtissues

Three-dimensional (3D) in vitro models of skeletal muscle are a valuable advancement in biomedical research as they afford the opportunity to study skeletal muscle reformation and function in a scalable format that is amenable to experimental manipulations. 3D muscle culture systems are desirable as they enable scientists to study skeletal muscle ex vivo in the context of human cells. 3D in vitro&#160;models closely mimic aspects of the native tissue structure of adult skeletal muscle. However, their universal application is limited by the availability of platforms that are simple to fabricate, cost and user-friendly, and yield relatively high quantities of human skeletal muscle tissues. Additionally, since skeletal muscle plays an important functional role that is impaired over time in many disease states, an experimental platform for microtissue studies is most practical when minimally invasive calcium transient and contractile force measurements can be conducted directly within the platform itself. In this protocol, the fabrication of a 96-well platform known as &#39;MyoTACTIC&#39;, and en masse production of 3D human skeletal muscle microtissues (hMMTs) is described. In addition, the methods for a minimally invasive application of electrical stimulation that enables repeated measurements of skeletal muscle force and calcium handling of each microtissue over time are reported.

This manuscript describes a detailed protocol to produce arrays of 3D human skeletal muscle microtissues and minimally invasive downstream in situ assays of function, including contractile force and calcium handling analyses.

İnsan İskelet Kas Mikrotissularında İskelet Kas Sağlığının Fonksiyonel Ölçümlerinin Değerlendirilmesi

Three-dimensional (3D) in vitro models of skeletal muscle are a valuable advancement in biomedical research as they afford the opportunity to study ...

Preclinical Drug Testing in Scalable 3D Engineered Muscle Tissues

Accurately modeling healthy and disease conditions in vitro is vital for the development of new treatment strategies and therapeutics. For cardiac and skeletal muscle diseases, contractile force and kinetics constitute key metrics for assessing muscle function. New and improved methods for generating engineered muscle tissues (EMTs) from induced pluripotent stem cells have made in vitro disease modeling more reliable for contractile tissues; however, reproducibly fabricating tissues from suspended cell cultures and measuring their contractility is challenging. Such techniques are often plagued with high failure rates and require complex instrumentation and customized data analysis routines. A new platform and device that utilizes 3D EMTs in conjunction with a label-free, highly-parallel, and automation-friendly contractility assay circumvent many of these obstacles. The platform enables facile and reproducible fabrication of 3D EMTs using virtually any cell source. Tissue contractility is then measured via an instrument that simultaneously measures 24 tissues without the need for complex software analysis routines. The instrument can reliably measure micronewton changes in force, allowing for dose-dependent compound screening to measure the effect of a drug or therapeutic on contractile output. Engineered tissues made with this device are fully functional, generating twitch and tetanic contractions upon electrical stimulation, and can be analyzed longitudinally in culture over weeks or months. Here, we show data from cardiac muscle EMTs under acute and chronic dosing with known toxicants, including a drug (BMS-986094) that was pulled from clinical trials after patient fatalities due to unanticipated cardiotoxicity. Altered skeletal muscle function in engineered tissues in response to treatment with a myosin inhibitor is also presented. This platform enables the researcher to integrate complex, information-rich bioengineered model systems into their drug discovery workflow with minimal additional training or skills required.

This protocol provides methods for generating 3D engineered cardiac and skeletal muscle tissues and describes their use in preclinical drug screening modalities. The described methods utilize a magnetic sensing system to facilitate the simultaneous assessment of 24 tissues in parallel.

Ölçeklenebilir 3D Mühendislik Kas Dokularında Preklinik İlaç Testi

Accurately modeling healthy and disease conditions in vitro is vital for the development of new treatment strategies and therapeutics. For cardiac and ...