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

أداء جميع التجارب على الحيوانات وفقا لبروتوكولات وافقت عليها اللجنة المؤسسية لاستخدام ورعاية الحيوانات المختبرية. 1. إعداد الثقافة وسائل الإعلام <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> جعل وسائل الإعلام ثقافة لخط الخلية الليفية ...

<ol>
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ويشير البروتوكول الحالي لوسريعة استراتيجية سليمة وبسيطة وفعالة وقابلة للتكرار الذي يمكن توليد الأنسجة المهندسة السفن الوظيفية باستخدام PiPSC من الخلايا الليفية الإنسان. هذه التقنية تمثل أداة قيمة للطب التجديدي، هندسة الأنسجة والعلاج بالخلايا يحتمل المريض محددة في ?...

بناء قنوات الأوعية الدموية هي استراتيجية أساسية للإصلاح الجراحي للتلف وإصابة الأوعية الناتجة عن أمراض القلب والأوعية الدموية. حتى الآن، والمواد الكسب غير المشروع المستخدمة في الجراحة وتشمل حيويا البوليمرات الاصطناعية (تترافلوروإيثيلين [تفلون]، وسعت تترافلوروإيثيلين [EPTFE، غور تكس] أو البولي ايثلين [الداكرون])، المغايرة، الأنسجة ذاتي (التامور أو الوريد الصافن) وxenografts 1. في حين الطعوم الاصطناعية (على سبيل المثال، غور تكس والداكرون) هي الأكثر شيوعا، وهذه المواد المحتمل أن يسبب العديد من المضاعفات على المدى القصير والمدى الطويل التي تشمل تضيق، ترسب الكالسيوم وخثرات الانصمام والالتهابات. على الرغم من أن المرضى الذين يعانون من الطعوم البيولوجية الحالية مع تراجع أحداث خثرات صمية، فإنها لا تزال تواجه القيود مثل فشل الكسب غير المشروع الثانوي والمتانة تقصير بسبب تدهور تكلس 2. لذلك، على الرغم من التحسينات الكبيرة في تي الجراحيةلا تزال مثقلة echniques على مر السنين، والباحثين والأطباء مع ضرورة تحديد قناة مثالية لأمراض الأوعية الدموية. وفي الآونة الأخيرة، وقد ولدت مجال أبحاث هندسة الأنسجة الوعائية مفهوم التي تدرج بها الخلايا في السقالات القابلة للتحلل، وذلك بهدف خلق بيئة بيوميمتيك التي تجسد سفينة الوظيفية لنجاح تطعيم 1. في الأساس، فإن نجاح يبني الأوعية الدموية يعتمد على ثلاثة عناصر أساسية. الخلايا التي تتكون من سقالة، أي طبقة داخلية خلية البطانية وطبقة الخلايا العضلية الملساء، سقالة تحتوي على المصفوفة خارج الخلية المناسبة لتوفير الخصائص الميكانيكية مماثلة لالأوعية الدموية الأصلي، والإشارات الجزيئية / الخلوي ما هو مطلوب لبدء / تنظيم إصلاح. طويلة المدى المباح الكسب غير المشروع والتنمية المستدامة للأنسجة الجدد تعتمد اعتمادا كبيرا على بذر خلية فعالة السقالات، عشرereby تقديم قرار نوع من الخلايا ذات أهمية حاسمة. وتظهر عدة تقارير استخدام البطانية ناضجة وخلايا العضلات الملساء من مصادر مختلفة لتطوير قنوات صغيرة قطرها 3-6. وعلى الرغم من واعدة، وعدم وجود السفن ذاتي كافية للحصول تبقى البطانية ناضجة وخلايا العضلات الملساء عبئا كبيرا. وفي الآونة الأخيرة، تم استغلال الخلايا الجذعية من مصادر مختلفة لتطبيقات هندسة الأنسجة الوعائية. خلايا وحيدات النوى في الواقع، ومجموعة متنوعة من أنواع الخلايا الجذعية بما في ذلك الخلايا الجذعية الجنينية 7، الناجم عن الخلايا الجذعية المحفزة (iPSCs) 8،9، PiPSC 10،11، والمستمدة نخاع العظم 12، الخلايا الجذعية الوسيطة 13، الخلايا الاصلية البطانية وجدار الوعاء الدموي الكبار -derived الخلايا الجذعية مستضد 1 (SCA-1) + الخلايا الجذعية / السلف كلها قد أثبتت 14،15 لتكون قادرة على التمايز إلى خلايا إما البطانية وظيفية أو العضلات الملساء ردا على وسائل الاعلام محددة وشروط الثقافة. وعلاوة على ذلك، فإن القدرة تجديد الذات غير محدودة من الخلايا الجذعية جعلها المرشحين الأفضل على عكس البطانية ناضجة وخلايا العضلات الملساء التي يمكن أن يقسم إلا لعدد محدود من المرات قبل ان يخضع لاعتقال النمو والشيخوخة. اختيار المواد سقالة لتوليد الأنسجة ناجحة سفينة هندسيا للتطعيم يعتمد على عدة عوامل مثل توافق مع الحياة، خصائص النشاط الحيوي، ومعدل التحلل البيولوجي. في الأساس، والمواد المستخدمة في إنشاء السقالات لترقيع يجب أن تكون قابلة للتحلل ولن جبل المتلقي لزوم لها الاستجابات المناعية. بالإضافة إلى ذلك، يجب أن تشمل المسامية مناسبة والمجهرية لمرفق الخلية والبقاء على قيد الحياة لاحق. حتى الآن، والمواد الأكثر شيوعا لالسقالات في هندسة الأنسجة الوعائية وتشمل البوليمرات من حمض polyglycolic، عديد حمض اللبنيك، وبولي ε-caprolactone 16. وفي الآونة الأخيرة، المواد البيولوجية decellularized لهاكما تم تطبيقه مع بعض النجاح. وقد أظهرت العديد من المختبرات التي البذر السفن الخنازير البشرية decellularized، والكلاب أو مع خلايا ذاتي قدمت الكسب غير المشروع البيولوجي التي قاومت تخثر وباطنة تضخم 17-19. وتشمل الاستراتيجيات الأخرى في هندسة الأنسجة الوعائية خارج الخلية ترقيع الأوعية الدموية القائمة على البروتينات المصفوفة على سبيل المثال، بذر الخلايا في الليفين هلام 13 وأوراق خلية توليد دون دعم سقالة 20 و 21. يوضح البروتوكول الحالي تمايز PiPSC الإنسان في البطانية الوظيفية وخلايا العضلات الملساء، وتوليد مفاعل حيوي يتكون من سقالة سفينة decellularized لإيواء خلايا الأوعية الدموية PiPSC المشتقة وظيفية، وترقيع الأوعية الأنسجة المهندسة إلى نقص المناعة الشديد مجتمعة (SCID ) الفئران. PiPSC تشكل نوع من الخلايا الأمثل لاستخدامها لهندسة الأنسجة الطعوم السفينة لأن هذه الخلايا لا تشكل الأورام في الفئران أو رفع الأخلاقي وردود ألو-المناعية. وعلاوة على ذلك، لقد أظهرنا أن استراتيجية لتوليد بالنقاط، البطانية الخلايا ونقطة على نحو سلس خلايا العضلات هي فعالة وقابلة للتكرار 10،11. بعد ذلك، قمنا بتصميم سفينة decellularized لزرع البذور من خلايا الأوعية الدموية PiPSC المشتقة من لتقليد بشكل وثيق البروتينات المصفوفة موجود داخل سفينة الأم، وبالتالي تعزيز التطعيم وبقاء فعالية. وعلاوة على ذلك، فإن decellularization من السفن قبل PiPSC البذر يمنع وقوع الاستجابات الالتهابية التي شنت من قبل أنواع الخلايا المناعية مثل الضامة. الأهم من ذلك، هذا البروتوكول لا تمثل سوى منهجية لتوليد واعدة قنوات الأوعية الدموية للترجمة إلى البشر، ولكنها توفر أيضا وسيلة قيمة لدراسة وفهم الآليات الجزيئية التي تتحكم في تجديد الأنسجة الوعائية من خلال نماذج الماوس.

<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.

وأكد الجيل الناجح لPiPSC 4 أيام بعد nucleofecting الخلايا الليفية الإنسان مع البلازميد pCAG2LMKOSimO خطي تحمل 4 عوامل النسخ، OCT4، SOX2، KLF4 وج-MYC (OSKM). PiPSC عرض النمط الظاهري واضح بشكل ملحوظ بالمقارنة مع الخلايا الليفية (الشكل 2A)، وأعرب عن عوامل إعادة برمجة 4 في مرنا (الشكل 2B)</stro...

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

هنا، نقدم بروتوكول لتوليد الأنسجة المهندسة ترقيع الأوعية التي هي وظيفية للتطعيم في الفئران عن طريق بذر المزدوج الناجم جزئيا الخلايا الجذعية المحفزة (PiPSC) - المشتقة خلايا العضلات الملساء وPiPSC - الخلايا البطانية مشتقة على decellularized سفينة سقالة مفاعل حيوي.

جيل ومسمار سفن الهندسة الأنسجة في نموذج الفأر

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.

بروتوكول لتقييم هيدرودينامي النسبية للثلاثي النشرة بوليمر صمامات

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.

إعداد الأغشية ضوء استجابة من قبل التطعيم سطح الجامع وعملية Postmodification

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.

تقنية جراحية لزرع الأنسجة المهندسة الأوعية الدموية الطعوم واللاحقة<em&gt; في فيفو</em&gt; الرصد

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.

جيل من سمك ثلاثي الأبعاد الجلد كامل أي ما يعادل واصابة الآلي

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.

إنتاج وتوصيف والمحتملة استخدامات الأنسجة المهندسة-3D الإنسان المريء المخاطي نموذج

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.

والأنسجة المشتركة 3D هندسيا<em&gt; في المختبر</em&gt; /<em&gt; في السيليكو</em&gt; الرئة نموذج الورم للتنبؤ فعالية الدواء في خلفيات الطفرات محددة

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.

تطبيقات<em&gt; في فيفو</em&gt; التجارب الفنية من الفئران قصبة الساق الأمامية لتقييم الأنسجة المهندسة وإصلاح العضلات والهيكل العظمي

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.

ثلاثي الأبعاد الأنسجة المهندسة الانحياز شبكات Astrocyte الخص الآليات الإنمائية وتيسير التجدد العصبي

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.

تقنية خياطة تينورهافي جديدة مع الأنسجة المهندسة الكولاجين الكسب غير المشروع لإصلاح عيوب وتر كبير

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.

بذر وغرس الاختلاس الرغامى السكروز هندسة الأنسجة في طراز الماوس

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