Yazarlar, sistem ve yazının hazırlanmasında yardım için Valtresa Myles tasarım ve üretim ile yardım için Shad Schipke ve Daniel Chesser minnettarız.

1. Doku Hasat ve Hazırlık <ol><li> Aort vanaları hemen ölümünden sonra en fazla 120 kg ağırlığında yetişkin domuz toplanan olmalıdır. </li><li> Valfler iki kez yıkayın steril fosfat tamponlu salin (PBS) ve buz üzerinde laboratuar ulaşım. </li><li> Tüm sonraki basamaklar steril şartlar altında yapılmalıdır. </li><li> Bu broşür, yırtılma ya da kireçlenme dejenerasyon herhangi bir işaret yok olun. Aort kökü broşürler annulus mesafenin 1 / 3 keserek çıkarın. </li><li> Yeri altı plaka bireysel kuyularda broşürler ve bir gecede 37 ° C ve% 5 CO 2% 1 anti-biotic/anti-mycotic çözüm ve% 10 fetal sığır serumu ile takviye 3ml Dulbecco&#39;nun Modifiye Kartal Orta kuluçkaya yatmaktadır. </li><li> Alternatif, izole hücreler altı kuyu kültür plakaları numaralı seribaşı ve basınçlı cihaz gibi. Daha önce açıklandığı gibi 13, 14 valf endotel hücreleri ve interstisyel hücre izolasyonu yapılabilir. </li></ol> 2. Basınç Çalışmaları <ol><li> Aort kapak dokusu 15 siklik basınç mechanobiological etkilerini incelemek amacıyla yapılmış özel bir basınç sistemi dizayn edilmiştir. </li><li> Bilgisayara oturum açın ve LabVIEW programı açın (Şekil 1). </li><li> Kalibrasyon: <ol><li> Öncesinde deney, sistemin düzgün kalibre edilmelidir. </li><li> Güç kaynağı devre kartına bağlayın. Bu odasına ve dışarı hava akışını kontrol solenoid valfler için güç sağlar. </li><li> Basınçlı hava sistemine bağlı olduğundan emin olun ve tam hızı ile hava beslemesi açık. </li><li> Sinyal amplifikatörü açın. Voltaj okuma 0.00 olduğundan emin olun. Gerektiği gibi ayarlayın. </li><li> LabVIEW arayüzü &quot;TEST / RECORD&quot; işaretli bir anahtarı vardır. Anahtarı &quot;TEST&quot; olarak ayarlanmış olduğundan emin olun. &quot;Hava İkmal giriş selenoid vana açmak için&quot; işaretli düğmeye tıklayın. </li><li> Gaz basınç regülatörü kullanarak, sıkıştırılmış hava ile odasına 1 PSI basınç. Odasında basınç odasının arka uç plakası bulunan dijital basınç göstergesi kullanılarak okunabilir. Basıncı dengelenir sonra, sinyal kuvvetlendirici voltaj okuma kaydedin. 2, 3, 4 ve 5 PSI tekrarlayın. </li><li> Basınç vs gerilim bir kalibrasyon eğrisi oluşturun. Basınç PSI mmHg dönüştürülmesi gerekir. LabVIEW programı kod grafikte denklemi içine yerleştirilebilir </li></ol></li><li> Alüminyum ön plaka basınç odasından çıkarın ve% 70 etanol ile odanın sprey. Kalan etanol dumanı dağıtmak için izin vermek için en az 10 dakika bekletin. </li><li> Odasına broşür örnekleri içeren altı plaka yerleştirin ve ön uç plakasını değiştirmek. Mühür, el ile uç plakası her köşesinde bulunan dört dişli çubuklar bulunan somunları sıkarak hava geçirmez olduğundan emin olun. 37 ° C inkübatör, basınç odasının yerleştirin. Basınç odasının şematik diyagramı Şekil 2&#39;de gösterilmiştir. </li><li> Kullanıcı arayüzü, basınçlı hava giriş ve çıkış arasındaki sistemi döngüleri zaman miktarını sağlamak için isteyecektir. Bu 1Hz bir sıklık sırasıyla, 0.6s ve taklit etmek 0.4s diyastolik ve sistolik koşulları, ayarlanmış olmalıdır. Kullanıcı ayrıca bir veri dosyası yolu girmeniz gerekir. </li><li> LabVIEW&#39;da çalıştırmak tıklayın ve &quot;TEST / RECORD&quot; &quot;KAYIT&quot; geçiş anahtarı. </li><li> Basınç LabVIEW arayüzü grafik kullanarak istenilen düzeyde olduğundan emin olun. Basınçlı gaz basınç regülatörü kullanarak ayarlanabilir. </li><li> Zaman istenilen uzunlukta için programı çalıştırın. </li><li> Deney tamamlandıktan sonra, LabVIEW üzerinde stop düğmesini tıklatın, hava kaynağı kapatmak ve basınç odasının egzoz valfi açık. </li><li> Ön uç plakası odasından çıkarın ve altı plaka içeren numuneler almak. Örnekleri gen ekspresyonu, protein ekspresyonu, histoloji, mekanik özellikleri vb analiz edilebilir </li></ol> 3. Temsilcisi Sonuçlar: Basınç sistemi normotansif altında gözlenen maksimum transvalvüler baskılara taklit yeteneğine sahip, I ve evre II hipertansif koşulları sahne. Ancak, basınç, in vivo olarak aslında sıfır sistolik basınç gradyan, taklit etmek mümkün değildi. Frekans 0.6s ve 0.4s bir egzoz kez bir hava giriş zamanı, 1Hz korunur. Sistemden elde edilen normal ya da yüksek basınç koşulları Temsilcisi basınç dalga şekilleri Şekil 3&#39;te görülebilir. <img src="/files/ftp_upload/3316/3316fig1.jpg" alt="Şekil 1"/> Şekil 1: LabVIEW arayüzünün ekran görüntüsü. <img src="/files/ftp_upload/3316/3316fig2.jpg" alt="Şekil 2"/> Şekil 2: Şematik çizim basınç odasının, basınç odasının A. İzometrik görünüm; basınç odasının B. Yandan görünüm;C. basınç odasının görünümü. <img src="/files/ftp_upload/3316/3316fig3.jpg" alt="Şekil 3"/> Şekil 3: (A) normotansif, (B) hipertansif Sahne, ve (C) Evre II hipertansif koşulları, basınç odasının içinde basınç simülasyon grafiği.

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Çıkar çatışması ilan etti.

Basınç sistemi başarıyla aort kapak broşürler, diastolik transvalvüler basınç temsilcisi siklik baskılara maruz. Ancak, sadece basıncı 40 mmHg düştü, sistolik transvalvüler basınç taklit etmek mümkün değildi. Transvalvüler basınç Asendan aorta ve sol ventrikül basıncı arasındaki farktır. Diyastol sırasında, kapak kapatıldığında, normotansif koşulları ve 90 mmHg altında basınç farkı 80mmHg ve evre I ve evre II hipertansiyon, sırasıyla 100mmHg. Sistol sırasında, kapak açık ol...

<table border="1"><tbody><tr><th> Reaktifin Adı </th><th> Şirket </th><th> Katalog numarası </th><th> Yorumlar (isteğe bağlı) </th></tr><tr><td> DMEM </td><td> Sigma </td><td> D5671 </td><td></td></tr><tr><td> Dulbecco&#39;nun PBS </td><td> Sigma </td><td> D5652 </td><td></td></tr><tr><td> Anti-mycotic/antibiotic çözüm </td><td> Sigma </td><td> A5955 </td><td></td></tr><tr><td> Fetal sığır serumu </td><td> ThermoScientific </td><td> SH30070 </td><td></td></tr><tr><td> Viton diyaframlı solenoid valfler </td><td> McMaster Carr </td><td> 4868K11 </td><td></td></tr><tr><td> Basınç Transducer </td><td> Omega Engineering, Inc. </td><td> PX302-200GV </td><td></td></tr><tr><td> Yük hücresi kremi </td><td> Encore Electronics, Inc. </td><td> 4025-101 </td><td></td></tr><tr><td> Veri Toplama (DAQ) Modülü </td><td> Ölçüm Bilgisayar </td><td> PMD1608 </td><td></td></tr></tbody></table>

design of a cyclic pressure bioreactor for the ex vivo study of aortic heart valves

Ventrikül içine geri akmasını önlemek, sol ventrikül ve aorta arasında bulunan aort kapak, tek yönlü kan akımını sağlar. Aort kapak broşürler, interstisyel hücreleri ve endotel hücre tek tabaka ile kaplı, bir ekstrasellüler matriks (ECM) içinde askıya oluşur. Vana sert, dinamik bir ortamda dayanıklıdır ve kesme, fleksiyon, gerginlik, ve sıkıştırma sürekli maruz kalmaktadır. Araştırma endotel bozulması veya interstisyel matris hasar 1-3 bir sonucu olarak, yüksek mekanik stres alanlarında meydana hastalıklı vanalar kalsifik lezyonlar göstermiştir . Bu nedenle, epidemiyolojik çalışmalarda yüksek kan basıncı, aort kapak hastalığı 4 başlangıcı önde gelen risk faktörü olarak göstermiştir ki şaşırtıcı değildir . Hastalıklı bir biyoprotez ve mekanik kapak 5 ile vana, kapak hastalığı için mevcut tek tedavi seçeneği cerrahi yerine geçer . Fiziksel strese yanıt olarak vana biyolojisinin daha iyi anlaşılması, valf patogenezinin mekanizmaları aydınlatmak yardımcı olacaktır. Buna karşılık, bu gibi ilaç müdahale ya da önlenmesi gibi non-invaziv tedavilerin geliştirilmesine yardımcı olabilir. Çeşitli biyoreaktörler daha önce, yerli veya mühendislik kalp kapakçıkları 6-9 mechanobiology okumak için geliştirilmiştir . Pulsatil biyoreaktörler da dahil olmak üzere dokularda kıkırdak 10, 11 kemik ve mesane 12 bir dizi çalışma için geliştirilmiştir. Bu çalışmanın amacı, yüksek basınç yükleri aort kapak broşür biyolojik yanıt aydınlatmak için kullanılan olabilir döngüsel bir basınç sistemi geliştirmek için oldu. Sistem örnekleri yer ve döngüsel basınç, basınç döngüsünün zamanlamasını kontrol etmek için viton diyafram solenoid valfler, ve elektrikli cihazları kontrol etmek için bir bilgisayar üretmek için akrilik bir odasının oluşuyordu. Basınç, basınç dönüştürücü kullanarak takip edildi ve sinyal bir yük hücresi kremi kullanılarak klimalı. LabVIEW programı uygun hızda sistem içine basınçlı hava pompalamak için bir analog cihaz kullanarak basınç düzenlenmiştir. Sistem, aort kapak ile ilişkili dinamik transvalvüler basınç seviyeleri taklit bir testere dişi dalga kapak açılışını temsil eden keskin bir basınç düşüşü takip diyastolde vana üzerinden mevcut olduğunu transvalvüler basınç gradiyenti tipik basınç kademeli bir artış, üretilen sistol. LabVIEW programı kullanıcıları siklik basınç büyüklüğü ve sıklığı kontrol etmek için izin verdi. Sistem basınç koşulları fizyolojik ve patolojik doku örnekleri konu başardı. Bu cihaz, kalp kapakçıkları, yerel mekanik çevre değişiklikleri nasıl cevap anlayışımızı artırmak için kullanılabilir.

Watch this Scientific Journal Video about Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves at JoVE.com

Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

Basınç koşulları fizyolojik ve patolojik kalp kapakçığı dokusu tabi yapabilen bir siklik basınç biyoreaktör dizayn edilmiştir. LabVIEW programı, kullanıcıların basınç büyüklüğü, genlik ve frekans kontrol etmenizi sağlar. Bu cihaz, kalp kapakçığı dokusu veya izole hücrelerin mechanobiology incelemek için kullanılabilir.

Devirli Basınç Biyoreaktör Tasarım Ex vivo</emAort Kalp Vanalar> Eğitim

The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic ...

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Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

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15.6K Görüntüleme.  Mississippi State University. Basınç koşulları fizyolojik ve patolojik kalp kapakçığı dokusu tabi yapabilen bir siklik basınç biyoreaktör dizayn edilmiştir. LabVIEW programı, kullanıcıların basınç büyüklüğü, genlik ve frekans kontrol etmenizi sağlar. Bu cihaz, kalp kapakçığı dokusu veya izole hücrelerin mechanobiology incelemek için kullanılabilir.

Video: Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations

Patient-specific simulations of heart (dys)function aimed at personalizing cardiac therapy are hampered by the absence of in vivo imaging technology for clinically acquiring myocardial fiber orientations. The objective of this project was to develop a methodology to estimate cardiac fiber orientations from in vivo images of patient heart geometries. An accurate representation of ventricular geometry and fiber orientations was reconstructed, respectively, from high-resolution ex vivo structural magnetic resonance (MR) and diffusion tensor (DT) MR images of a normal human heart, referred to as the atlas. Ventricular geometry of a patient heart was extracted, via semiautomatic segmentation, from an in vivo computed tomography (CT) image. Using image transformation algorithms, the atlas ventricular geometry was deformed to match that of the patient. Finally, the deformation field was applied to the atlas fiber orientations to obtain an estimate of patient fiber orientations. The accuracy of the fiber estimates was assessed using six normal and three failing canine hearts. The mean absolute difference between inclination angles of acquired and estimated fiber orientations was 15.4 &deg;. Computational simulations of ventricular activation maps and pseudo-ECGs in sinus rhythm and ventricular tachycardia indicated that there are no significant differences between estimated and acquired fiber orientations at a clinically observable level.The new insights obtained from the project will pave the way for the development of patient-specific models of the heart that can aid physicians in personalized diagnosis and decisions regarding electrophysiological interventions.

A methodology to estimate ventricular fiber orientations from in vivo images of patient heart geometries for personalized modeling is described. Validation of the methodology performed using normal and failing canine hearts demonstrate that that there are no significant differences between estimated and acquired fiber orientations at a clinically observable level.

Kalp Hastaya özel Modelleme: Ventriküler Fiber Yönelimlerin Tahmini

Patient-specific  simulations of heart (dys)function aimed at personalizing cardiac therapy are hampered  by the absence of in vivo imaging technology for ...

Biyomühendislik

Design of a Biaxial Mechanical Loading Bioreactor for Tissue Engineering

We designed a loading device that is capable of applying uniaxial or biaxial mechanical strain to a tissue engineered biocomposites fabricated for transplantation. While the device primarily functions as a bioreactor that mimics the native mechanical strains, it is also outfitted with a load cell for providing force feedback or mechanical testing of the constructs. The device subjects engineered cartilage constructs to biaxial mechanical loading with great precision of loading dose (amplitude and frequency) and is compact enough to fit inside a standard tissue culture incubator. It loads samples directly in a tissue culture plate, and multiple plate sizes are compatible with the system. The device has been designed using components manufactured for precision-guided laser applications. Bi-axial loading is accomplished by two orthogonal stages. The stages have a 50 mm travel range and are driven independently by stepper motor actuators, controlled by a closed-loop stepper motor driver that features micro-stepping capabilities, enabling step sizes of less than 50 nm. A polysulfone loading platen is coupled to the bi-axial moving platform. Movements of the stages are controlled by Thor-labs Advanced Positioning Technology (APT) software. The stepper motor driver is used with the software to adjust load parameters of frequency and amplitude of both shear and compression independently and simultaneously. Positional feedback is provided by linear optical encoders that have a bidirectional repeatability of 0.1 &mu;m and a resolution of 20 nm, translating to a positional accuracy of less than 3 &mu;m over the full 50 mm of travel. These encoders provide the necessary position feedback to the drive electronics to ensure true nanopositioning capabilities. In order to provide the force feedback to detect contact and evaluate loading responses, a precision miniature load cell is positioned between the loading platen and the moving platform. The load cell has high accuracies of 0.15% to 0.25% full scale.

We designed a novel mechanical loading bioreactor that can apply uniaxial or biaxial mechanical strain to a cartilage biocomposite prior to transplantation into an articular cartilage defect.

Doku Mühendisliği için iki eksenli Mekanik Yükleniyor Biyoreaktör tasarımı

We  designed a loading device that is capable of applying uniaxial or biaxial  mechanical strain to a tissue engineered biocomposites fabricated for  ...

Operation of a Benchtop Bioreactor

Fermentation systems are used to provide an optimal growth environment for many different types of cell cultures. The ability afforded by fermentors to carefully control temperature, pH, and dissolved oxygen concentrations in particular makes them essential to efficient large scale growth and expression of fermentation products. This video will briefly describe the advantages of the fermentor over the shake flask. It will also identify key components of a typical benchtop fermentation system and give basic instruction on setup of the vessel and calibration of its probes. The viewer will be familiarized with the sterilization process and shown how to inoculate the growth medium in the vessel with culture. Basic concepts of operation, sampling, and harvesting will also be demonstrated. Simple data analysis and system cleanup will also be discussed.

Fermentors are used to increase culture yield and productivity of bioengineered cells. After screening multiple microbial or animal cell culture candidates in shake flasks, the next logical step is to increase the selected culture&#x2019;s biomass with the fermentor. This video demonstrates the setup and operation of a typical benchtop bioreactor system.

Bir Benchtop Biyoreaktör Operasyonu

Fermentation systems are used to provide an optimal growth environment for many different types of cell cultures. The ability afforded by fermentors to ...

Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study

Plants provide multiple benefits for the production of biopharmaceuticals including low costs, scalability, and safety. Transient expression offers the additional advantage of short development and production times, but expression levels can vary significantly between batches thus giving rise to regulatory concerns in the context of good manufacturing practice. We used a design of experiments (DoE) approach to determine the impact of major factors such as regulatory elements in the expression construct, plant growth and development parameters, and the incubation conditions during expression, on the variability of expression between batches. We tested plants expressing a model anti-HIV monoclonal antibody (2G12) and a fluorescent marker protein (DsRed). We discuss the rationale for selecting certain properties of the model and identify its potential limitations. The general approach can easily be transferred to other problems because the principles of the model are broadly applicable: knowledge-based parameter selection, complexity reduction by splitting the initial problem into smaller modules, software-guided setup of optimal experiment combinations and step-wise design augmentation. Therefore, the methodology is not only useful for characterizing protein expression in plants but also for the investigation of other complex systems lacking a mechanistic description. The predictive equations describing the interconnectivity between parameters can be used to establish mechanistic models for other complex systems.

We describe a design of experiments approach that can be used to determine and model the influence of transgene regulatory elements, plant growth and development parameters, and incubation conditions on the transient expression of monoclonal antibodies and reporter proteins in plants.

Bir Vaka Çalışması Olarak Tütün Geçici Protein Expression: Deneyler Yaklaşımı Tasarım Kullanma Karmaşık Sistemler Karakterizasyonu

Plants provide multiple benefits for the production of biopharmaceuticals including low costs, scalability, and safety. Transient expression offers the ...

Anatomically Realistic Neonatal Heart Model for Use in Neonatal Patient Simulators

Neonatal patient simulators (NPS) are artificial patient surrogates used in the context of medical simulation training. Neonatologists and nursing staff practice clinical interventions such as chest compressions to ensure patient survival in the case of bradycardia or cardiac arrest. The simulators used currently are of low physical fidelity and therefore cannot provide qualitative insight into the procedure of chest compressions. The embedding of an anatomically realistic heart model in future simulators enables the detection of cardiac output generated during chest compressions; this can provide clinicians with an output parameter, which can deepen the understanding of the effect of the compressions in relation to the amount of blood flow generated. Before this monitoring can be achieved, an anatomically realistic heart model must be created containing: two atria, two ventricles, four heart valves, pulmonary veins and arteries, and systemic veins and arteries. This protocol describes the procedure for creating such a functional artificial neonatal heart model by utilizing a combination of magnetic resonance imaging (MRI), 3D printing, and casting in the form of cold injection molding. Using this method with flexible 3D printed inner molds in the injection molding process, an anatomically realistic heart model can be obtained.

This protocol describes a procedure for creating functional artificial neonatal heart models by utilizing a combination of magnetic resonance imaging, 3D printing, and injection molding. The purpose of these models is for integration into the next generation of neonatal patient simulators and as a tool for physiological and anatomical studies.

Anatomik olarak gerçekçi yenidoğan kalp modeli kullanılmak üzere yenidoğan hasta simülatörleri

Neonatal patient simulators (NPS) are artificial patient surrogates used in the context of medical simulation training. Neonatologists and nursing staff ...

Light-sheet Fluorescence Microscopy for the Study of the Murine Heart

Light-sheet fluorescence microscopy has been widely used for rapid image acquisition with a high axial resolution from micrometer to millimeter scale. Traditional light-sheet techniques involve the use of a single illumination beam directed orthogonally at sample tissue. Images of large samples that are produced using a single illumination beam contain stripes or artifacts and suffer from a reduced resolution due to the scattering and absorption of light by the tissue. This study uses a dual-sided illumination beam and a simplified CLARITY optical clearing technique for the murine heart. These techniques allow for deeper imaging by removing lipids from the heart and produce a large field of imaging, greater than 10 x 10 x 10 mm3. As a result, this strategy enables us to quantify the ventricular dimensions, track the cardiac lineage, and localize the spatial distribution of cardiac-specific proteins and ion-channels from the post-natal to adult mouse hearts with sufficient contrast and resolution.

This study uses a dual-sided illumination light-sheet fluorescence microscopy (LSFM) technique combined with optical clearing to study the murine heart.

Fare kalp çalışma için ışık sayfalık floresans mikroskobu

Light-sheet fluorescence microscopy has been widely used for rapid image acquisition with a high axial resolution from micrometer to millimeter scale. ...

A New Ex Vivo Model for the Evaluation of Endoscopic Submucosal Injection Material Performance

Increasing the performance of submucosal injection materials (SIMs) is important for endoscopic therapy of early gastrointestinal cancer. It is essential to establish an ex vivo model that can evaluate SIM performance accurately, for developing high-performance SIMs. In our previous study, we developed a new ex vivo model that can be used to evaluate the performance of various SIMs in detail by applying constant tension to the specimen&#39;s ends. We also confirmed that the proposed new ex vivo model allows accurate submucosal elevation height (SEH) measurement under uniform conditions and detailed comparisons of the performances of various types of SIMs. Here, we describe the new ex vivo model and explain the detailed setup methodology of this model. Since all parts of the new model were easy to obtain, the setup of the new model could be completed quickly. SEH of various SIMs could be measured more accurately by using the new model. The critical factor that determines SIM performance can be identified using the new model. SIM development speed will drastically increase after the factor has been identified.

A New Ex Vivo Model for the Evaluation of Endoscopic Submucosal Injection Material Performance

We developed a new ex vivo model that applies constant tension to the porcine gastric specimen. This development made it possible to evaluate the performance (the height and duration of the submucosal elevation) of various SIMs accurately.&#160; The detailed setup methodology of this new model is explained.

Endoskopik Submucosal enjeksiyon malzemesi performans değerlendirilmesi için yeni bir Ex Vivo Model

Increasing the performance of submucosal injection materials (SIMs) is important for endoscopic therapy of early gastrointestinal cancer. It is essential ...

Biaxial Mechanical Characterizations of Atrioventricular Heart Valves

Extensive biaxial mechanical testing of the atrioventricular heart valve leaflets can be utilized to derive&#160;optimal parameters used in constitutive models, which provide a mathematical representation of the mechanical function of those structures. This presented biaxial mechanical testing protocol involves (i) tissue acquisition, (ii) the preparation of tissue specimens, (iii) biaxial mechanical testing, and (iv) postprocessing of the acquired data. First, tissue acquisition requires obtaining porcine or ovine hearts from a local Food and Drug Administration-approved abattoir for later dissection to retrieve the valve leaflets. Second, tissue preparation requires using tissue specimen cutters on the leaflet tissue to extract a clear zone for testing. Third, biaxial mechanical testing of the leaflet specimen requires the use of a commercial biaxial mechanical tester, which consists of force-controlled, displacement-controlled, and stress-relaxation testing protocols to characterize the leaflet tissue&#39;s mechanical properties. Finally, post-processing requires the use of data image correlation techniques and force and displacement readings to summarize the tissue&#39;s mechanical behaviors in response to external loading. In general, results from biaxial testing demonstrate that the leaflet tissues yield a nonlinear, anisotropic mechanical response. The presented biaxial testing procedure is advantageous to other methods since the method presented here allows for a more comprehensive characterization of the valve leaflet tissue under one unified testing scheme, as opposed to separate testing protocols on different tissue specimens. The proposed testing method has its limitations in that shear stress is potentially present in the tissue sample. However, any potential shear is presumed negligible.

This protocol involves characterizations of atrioventricular valve leaflets with force-controlled, displacement-controlled, and stress-relaxation biaxial mechanical testing procedures. Results acquired with this protocol can be used for constitutive model development to simulate the mechanical behavior of functioning valves under a finite element simulation framework.

Atriyoventriküler kalp kapakları biaxial mekanik karakterizasyonu

Extensive biaxial mechanical testing of the atrioventricular heart valve leaflets can be utilized to derive&#160;optimal parameters used in constitutive ...

A Friction Testing-Bioreactor Device for Study of Synovial Joint Biomechanics, Mechanobiology, and Physical Regulation

In primary osteoarthritis (OA), normal 'wear and tear' associated with aging inhibits the ability of cartilage to sustain its load-bearing and lubrication functions, fostering a deleterious physical environment. The frictional interactions of articular cartilage and synovium may influence joint homeostasis through tissue level wear and cellular mechanotransduction. To study these mechanical and mechanobiological processes, a device capable of replicating the motion of the joint is described. The friction testing device controls the delivery of reciprocal translating motion and normal load to two contacting biological counterfaces. This study adopts a synovium-on-cartilage configuration, and friction coefficient measurements are presented for tests performed in a phosphate-buffered saline (PBS) or synovial fluid (SF) bath. The testing was performed for a range of contact stresses, highlighting the lubricating properties of SF under high loads. This friction testing device can be used as a biomimetic bioreactor for studying the physical regulation of living joint tissues in response to applied physiologic loading associated with diarthrodial joint articulation.

The present protocol describes a friction testing device that applies simultaneous reciprocal sliding and normal load to two contacting biological counterfaces.

Sinovyal Eklem Biyomekaniği, Mekanobiyoloji ve Fiziksel Regülasyon Çalışmaları için Bir Sürtünme Testi-Biyoreaktör Cihazı

In primary osteoarthritis (OA), normal 'wear and tear' associated with aging inhibits the ability of cartilage to sustain its load-bearing and lubrication ...

Procurement and Decellularization of Rat Hindlimbs Using an Ex Vivo Perfusion-Based Bioreactor for Vascularized Composite Allotransplantation

Patients with severe traumatic injuries and tissue loss require complex surgical reconstruction. Vascularized composite allotransplantation (VCA) is an evolving reconstructive avenue for transferring multiple tissues as a composite subunit. Despite the promising nature of VCA, the long-term immunosuppressive requirements are a significant limitation due to the increased risk of malignancies, end-organ toxicity, and opportunistic infections. Tissue engineering of acellular composite scaffolds is a potential alternative in reducing the need for immunosuppression. Herein, the procurement of a rat hindlimb and its subsequent decellularization using sodium dodecyl sulfate (SDS) is described. The procurement strategy presented is based upon the common femoral artery. A machine perfusion-based bioreactor system was constructed and used for ex vivo decellularization of the hindlimb. Successful perfusion decellularization was performed, resulting in a white translucent-like appearance of the hindlimb. An intact, perfusable, vascular network throughout the hindlimb was observed. Histological analyses showed the removal of nuclear contents and the preservation of tissue architecture across all tissue compartments.

Procurement and Decellularization of Rat Hindlimbs Using an Ex Vivo Perfusion-Based Bioreactor for Vascularized Composite Allotransplantation

We describe the surgical technique and decellularization process for composite rat hindlimbs. Decellularization is conducted using low-concentration sodium dodecyl sulfate through an ex vivo machine perfusion system.

Vaskülarize Kompozit Allotransplantasyon için Ex Vivo Perfüzyon Bazlı Biyoreaktör Kullanılarak Sıçan Arka Bacaklarının Tedariği ve Desellülarizasyonu

Patients with severe traumatic injuries and tissue loss require complex surgical reconstruction. Vascularized composite allotransplantation (VCA) is an ...

Devirli Basınç Biyoreaktör Tasarım Ex vivo Eğitim