作者感谢他们的设计和制造系统，并与准备的稿子援助Valtresa迈尔斯的协助下沙德Schipke和丹尼尔Chesser。

1。组织收获和准备<ol><li>应收集称重后立即死亡的不超过120磅的成年猪主动脉瓣。 </li><li>阀门两次洗净，用无菌磷酸盐缓冲液（PBS）和运输上冰实验室。 </li><li>应在无菌条件下进行的所有后续步骤。 </li><li>确保，单张不显示任何退化的迹象，撕裂或钙化。删除从纤维环削减1 / 3的距离从主动脉根部的宣传单张。 </li><li>放置传单，在六孔板个别井和3毫升贝科改良Eagle 1％anti-biotic/anti-mycotic解决方案，并在37 ° C和5％的CO 2 10％胎牛血清培养基孵育过夜。 </li><li>作为一种替代方法，分离出的细胞可以接种到6孔培养板，压力设备中使用的。如前所述13，14阀内皮细胞和间质细胞的分离，可以进行。 </li></ol> 2。压力研究<ol><li>一个特制的压力系统的设计研究循环压力的主动脉瓣组织15 mechanobiological影响。 </li><li>登录到计算机上，打开LabVIEW程序（图1）。 </li><li>校准： <ol><li>试验之前，该系统应正确校准。 </li><li>连接到电路板的电源。这提供电源的电磁阀控制流入和流出的空气室的流动。 </li><li>确保压缩空气系统连接，并打开送风全速度。 </li><li>开启的信号放大器。确保电压读数是0.00。根据需要调整</li><li> LabVIEW的接口标有“测试/记录”的一个开关。确保将开关设置为“test”。点击标有“空气补给”，打开进水电磁阀“按钮。 </li><li>使用燃气压力调节器，用压缩空气加压室1 PSI。在会议厅内的压力可以读取使用位于室的后端板的数字压力表。一旦压力平衡，记录信号放大器的电压读数。重复2，3，4和5 PSI。 </li><li>构建的压力与电压的校准曲线。压力应该从PSI的转换，以毫米汞柱。从图中的计算公式可以被放置到LabVIEW程序代码</li></ol></li><li>从压力室中删除的铝制前板和喷雾室，用70％乙醇。至少10分钟离开，让残留的乙醇气体消散。 </li><li>将6孔板单张样本含有进入会议厅和更换前端板。确保密封不透气收紧位于四个螺纹杆（位于终板的每个角落）手工坚果。将在37℃孵化器压力室。一个压力室的示意图如图2所示。 </li><li>该界面会提示用户提供的压缩空气输入和输出之间的时间系统周期量。这些应设置为0.6S和0.4秒模仿的舒张压和收缩压的条件下，分别在频率为1Hz，。用户还应该输入数据文件的路径。 </li><li>在LabVIEW中，单击“运行”和“测试/记录”切换开关“录制”。 </li><li>确保在使用LabVIEW的接口图所需的水平压力。压力可以调整使用的燃气调压。 </li><li>运行程序所需的时间长度。 </li><li>一旦实验完成后，单击“基于LabVIEW的停止按钮，关掉供气，打开排气阀上的压力室。 </li><li>从室取出前端板和检索六孔板样品。现在可以分析基因表达，蛋白表达，组织学，力学性能等样品</li></ol> 3。代表性的成果： 压力系统是能够模拟正常血压下观察到的最大跨瓣压力，阶段I和第II阶段的高血压的条件。然而，压力是不能够模仿的收缩压梯度，这基本上是零，在体内。保持以1Hz的频率，0.6S的进气口和排气时间的0.4秒时间。代表从系统中获得的条件正常和压力升高的压力波形图3中可以看出。 <img src="/files/ftp_upload/3316/3316fig1.jpg" alt="图1"/> 图1：LabVIEW的接口的屏幕截图。 <img src="/files/ftp_upload/3316/3316fig2.jpg" alt="图2"/> 图2：A.压力腔压力腔等轴测视图示意图; B.压力室的侧视图;C.压力室的顶视图。 <img src="/files/ftp_upload/3316/3316fig3.jpg" alt="图3"/> 图3：图内的压力腔的压力模拟（一）血压正常，（二）第一阶段高血压，和（C）第二阶段高血压条件。

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没有利益冲突的声明。

压力系统成功地暴露了主动脉瓣舒张期跨瓣压差，分别代表循环压力。然而，这是不能够模仿收缩跨瓣压差，压力仅下降40毫米汞柱。跨瓣压差在升主动脉和左心室之间的压力差。在舒张期，当阀门关闭时，压力差是80mmHg血压正常的条件下和90毫米汞柱，并在第一阶段100mmHg我和第二阶段的高血压，分别为。在收缩过程中，当阀门打开时，左心室和主动脉之间的压力差为零。发生在主动脉瓣病变的?...

<table border="1"><tbody><tr><th>试剂名称</th><th>公司</th><th>目录编号</th><th>评论（可选） </th></tr><tr><td> DMEM培养液</td><td>西格玛</td><td> D5671 </td><td></td></tr><tr><td>贝科的PBS </td><td>西格玛</td><td> D5652 </td><td></td></tr><tr><td> Anti-mycotic/antibiotic解决方案</td><td>西格玛</td><td> A5955 </td><td></td></tr><tr><td>胎牛血清</td><td> ThermoScientific </td><td> SH30070 </td><td></td></tr><tr><td>氟橡胶膜片电磁阀</td><td>麦克马斯特卡尔</td><td> 4868K11 </td><td></td></tr><tr><td>压力传感器</td><td> Omega工程公司</td><td> PX302 - 200GV </td><td></td></tr><tr><td>称重传感器空调</td><td>喝采电子，公司</td><td> 4025-101 </td><td></td></tr><tr><td>数据采集​​（DAQ）模块</td><td> Measurement Computing公司</td><td> PMD1608 </td><td></td></tr></tbody></table>

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

主动脉瓣，左心室和主动脉之间，允许单向血流量，防止回流入脑室。主动脉瓣叶内细胞外基质（ECM）暂停，内衬内皮细胞单层的间质细胞组成。该阀门可承受苛刻的，动态的环境和不断暴露剪切，前屈，张力和压缩。研究表明病变瓣膜钙化病变发生在机械应力高的地区作为内皮细胞破坏或间质性基质损害 1-3的结果。因此，这并不奇怪，流行病学研究表明高血压，要在一个主要危险因素的主动脉瓣病变 4的发生。 目前瓣膜病唯一的治疗选择是一个bioprosthetic或机械瓣膜病变瓣膜置换手术。物理讲改进阀生物学的了解将有助于阐明阀的发病机制。反过来，这将有助于在非侵入性治疗，如医药干预或预防的发展。几个生物反应器，此前已开发研究本地或工程心脏瓣膜6-9 mechanobiology。脉动生物反应器也已发展到包括软骨，骨 11 10和12膀胱组织的研究范围。这项工作的目的是发展循环压力系统，可以用来澄清压力负荷增加的主动脉瓣叶的生物反应。 该系统由丙烯酸商会在其中放置样品和生产循环的压力，氟橡胶膜片电磁阀控制压力周期的时间，和一台计算机来控制电气设备。压力监测使用的压力传感器，空调使用的信号是一个负载单元空调。一个LabVIEW程序规范使用模拟设备系统，在适当的速度泵入压缩空气的压力。该系统模仿与主动脉瓣跨瓣压差的动态水平;一个锯齿波产生的压力逐渐增加，典型的是目前在舒张期，阀门两端的跨瓣压差梯度，压力急剧描绘阀门的开度在下降收缩。 LabVIEW程序允许用户控制循环压力的大小和频率。该系统能够受到生理和病理的压力条件下的组织样本。此设备可用于增加心脏瓣膜如何应对在当地的机械环境的变化的认识。

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

循环压力的心脏瓣膜组织遭受的生理和病理的压力条件下的生物反应器已经设计。一个LabVIEW程序允许用户控制压力的大小，幅度和频率。此装置可用于研究心脏瓣膜组织或孤立的细胞mechanobiology。

循环压力为生物反应器的设计体外主动脉心脏瓣膜的研究

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 次观看.  Mississippi State University. 循环压力的心脏瓣膜组织遭受的生理和病理的压力条件下的生物反应器已经设计。一个LabVIEW程序允许用户控制压力的大小，幅度和频率。此装置可用于研究心脏瓣膜组织或孤立的细胞mechanobiology。

视频: 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.

病人的具体建模之心：的心室纤维方向估计

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

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生物工程

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.

组织工程生物反应器的双轴机械装载设计

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.

一个台式生物反应器的操作

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.

烟草中瞬时表达的蛋白作为一个案例研究：复杂系统采用的实验方法设计的表征

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.

在新生儿患者模拟器中使用的解剖现实新生儿心脏模型

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.

光片荧光显微术在小鼠心脏研究中的应用

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.

内镜下黏膜下注射材料性能评价的一种新的体内模型

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.

房室心脏瓣膜的双轴力学特性

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.

一种摩擦试验-用于研究滑膜关节生物力学、机械生物学和物理调节的生物反应器装置

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.

使用 离体 灌注生物反应器进行大鼠后肢的获取和去细胞化血管化复合同种异体移植

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