המחברים מודים שאד Schipke ודניאל Chesser עזרתם בעיצוב ייצור של המערכת מיילס Valtresa לסיוע בהכנת כתב היד.

1. רקמות קציר הכנה <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> שסתומים אבי העורקים צריכה להיות שנאספו חזירים מבוגר במשקל של לא יותר מ 120 £ מיד לאחר מותו. </li><li style=";text-align:right;direction:rtl"> שטפו את השסתומים פעמיים עם פוספט סטרילי שנאגרו מלוחים (PBS) הובלה למעבדה על הקרח. </li><li style=";text-align:right;direction:rtl"> כל הצעדים הבאים צריכים להתבצע בתנאים סטריליים. </li><li style=";text-align:right;direction:rtl"> ודא כי הכרוזים אינם מראים כל סימן של ניוון, קריעה או הסתיידות. הסר כרוזים מן השורש על ידי חיתוך אבי העורקים 1 / 3 של המרחק annulus. </li><li style=";text-align:right;direction:rtl"> המקום עלונים בבארות בודדים של צלחת שישה היטב דגירה לילה עם בינוני השתנה הנשר 3ml של Dulbecco להשלים עם פתרון anti-biotic/anti-mycotic 1% ו -10% בסרום שור העובר על 37 ° C ו 5% CO 2. </li><li style=";text-align:right;direction:rtl"> כחלופה, תאים מבודדים ניתן seeded לתוך שש צלחות היטב בתרבות בשימוש במכשיר לחץ. בידוד של תאים שסתום אנדותל ותאים ביניים יכול להתבצע כפי שתואר לעיל 13, 14. </li></ol> 2. לחץ מחקרים <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> מערכת מחוייט לחץ תוכנן כדי לחקור את ההשפעות של הלחץ mechanobiological מחזורית על רקמת שסתום אבי העורקים 15. </li><li style=";text-align:right;direction:rtl"> היכנס למחשב, לפתוח את התוכנית LabVIEW (איור 1). </li><li style=";text-align:right;direction:rtl"> כיול: <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> לפני ניסויים, המערכת צריכה להיות מכויל כראוי. </li><li style=";text-align:right;direction:rtl"> חבר את ספק הכוח המעגל. זה מספק הכוח שסתומים סולנואיד כי שליטה על זרימת האוויר לתוך ומחוץ לתא. </li><li style=";text-align:right;direction:rtl"> ודא אוויר דחוס הוא מחובר למערכת ולפתוח את אספקת האוויר למהירות מלאה. </li><li style=";text-align:right;direction:rtl"> הפעל את המגבר האות. ודא קריאת מתח 0.00. כוון לפי הצורך </li><li style=";text-align:right;direction:rtl"> ממשק LabVIEW יש מתג מסומן &quot;TEST / שיא&quot;. ודא את המתג מוגדר &quot;TEST&quot;. לחץ על הלחצן שכותרתו &quot;אספקת אוויר&quot; כדי לפתוח את שסתום היניקה סולנואיד. </li><li style=";text-align:right;direction:rtl"> באמצעות ווסת לחץ הגז, לחצים על החדר עם אוויר דחוס ב 1 PSI. הלחץ בתא ניתן לקרוא באמצעות מד לחץ דיגיטלי הממוקם על הקצה האחורי צלחת של החדר. לאחר הלחץ יש equilibrated, להקליט את הקריאה מתח מ מגבר את האות. חזור עבור PSI 2, 3, 4 ו -5. </li><li style=";text-align:right;direction:rtl"> בניית עקומת כיול של לחץ מול מתח. הלחץ צריך להיות המרה ל PSI מ&quot;מ כספית. המשוואה מן הגרף ניתן להציב לתוך הקוד של התוכנית LabVIEW </li></ol></li><li style=";text-align:right;direction:rtl"> הסר את הלוח הקדמי אלומיניום מבית הבליעה לחץ ולרסס את החדר עם אתנול 70%. השאירו למשך תקופה מינימלית של 10 דקות כדי לאפשר אדי אתנול שיורית להתפוגג. </li><li style=";text-align:right;direction:rtl"> מניחים את צלחת שש היטב המכילה את דגימות כרוז אל תוך החדר ולהחליף את צלחת הקדמי. ודא החותם הוא אטום על ידי הידוק אגוזים ממוקמת על ארבעה מוטות הברגה (נמצא בכל פינה של צלחת סוף) ביד. הנח את תא הלחץ ב 37 מעלות צלזיוס חממה. תרשים סכמטי של תא הלחץ שמוצג באיור 2. </li><li style=";text-align:right;direction:rtl"> ממשק תנחה את המשתמש על מנת לספק את כמות הזמן בין מחזורי מערכת קלט ופלט אוויר דחוס. אלה צריך להיות מוגדר התנאים הסיסטולי והדיאסטולי ואת 0.6s ו 0.4s לחקות, בהתאמה, בתדר של 1Hz. המשתמש צריך גם להזין נתיב קובץ הנתונים. </li><li style=";text-align:right;direction:rtl"> ב LabVIEW, לחץ לרוץ לעבור &quot;מבחן / RECORD&quot; לעבור את &quot;שיא&quot;. </li><li style=";text-align:right;direction:rtl"> ודא הלחץ הוא ברמה הרצויה באמצעות גרף על ממשק LabVIEW. לחץ יכול להיות מותאם באמצעות ווסת לחץ הגז. </li><li style=";text-align:right;direction:rtl"> הפעלת התוכנית לאורך הזמן הרצוי. </li><li style=";text-align:right;direction:rtl"> לאחר הניסוי הושלם, לחץ על כפתור לעצור על LabVIEW, לכבות את אספקת האוויר ולפתוח את שסתום הפליטה על תא הלחץ. </li><li style=";text-align:right;direction:rtl"> הסר את צלחת הקצה הקדמי של החדר ולאחזר שש דגימות גם צלחת ובה. דוגמאות ניתן כעת ניתח עבור ביטוי גנים, ביטוי חלבון, היסטולוגיה, תכונות מכניות וכו &#39; </li></ol> 3. נציג תוצאות: מערכת הלחץ הוא מסוגל לדמות את הלחצים transvalvular המרבי נצפה תחת normotensive, יתר לחץ דם בשלב התנאים ואני בשלב II. עם זאת, הלחץ לא היה מסוגל לחקות את הלחץ הסיסטולי הדרגתי, שהוא בעצם אפס in vivo. תדירות נשמר 1Hz, עם זמן אוויר מפרצון של 0.6s ואת זמן פליטה של ​​0.4s. נציג גל הלחץ של התנאים לחץ נורמלי גבוהות המתקבל המערכת ניתן לראות באיור 3. <img src="/files/ftp_upload/3316/3316fig1.jpg" alt="איור 1"/> איור 1: צילום מסך של ממשק LabVIEW. <img src="/files/ftp_upload/3316/3316fig2.jpg" alt="איור 2"/> איור 2: ציור סכמטי של תא הלחץ להציג א איזומטרי של תא הלחץ, להציג צד ב &#39;של תא הלחץ;נוף ג לראש תא הלחץ. <img src="/files/ftp_upload/3316/3316fig3.jpg" alt="איור 3"/> איור 3: תרשים של סימולציה לחץ בתוך תא הלחץ (A) normotensive, (ב) שלב I יתר לחץ דם, ו - (ג) שלב II תנאים יתר לחץ דם.

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המערכת חשופה ללחץ בהצלחה עלונים שסתום אבי העורקים ללחצים מחזורית שהיו נציג הלחץ הדיאסטולי transvalvular. עם זאת, לא הצליחה לחקות את הלחץ הסיסטולי transvalvular, כמו הלחץ רק ירד ל 40 מ&quot;מ כספית. לחץ Transvalvular ההבדל בין הלחץ באבי העורקים העולה ואת החדר השמאלי. במהלך דיאסטולה, כאשר שסתו...

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><th> שם מגיב </th><th> חברה </th><th> מספר קטלוגי </th><th> הערות (אופציונלי) </th></tr><tr><td> DMEM </td><td> סיגמא </td><td> D5671 </td><td></td></tr><tr><td> Dulbecco של PBS </td><td> סיגמא </td><td> D5652 </td><td></td></tr><tr><td> Anti-mycotic/antibiotic פתרון </td><td> סיגמא </td><td> A5955 </td><td></td></tr><tr><td> סרום שור עוברית </td><td> ThermoScientific </td><td> SH30070 </td><td></td></tr><tr><td> סולנואיד Viton הסרעפת שסתומים </td><td> מקמאסטר קאר </td><td> 4868K11 </td><td></td></tr><tr><td> לחץ מתמר </td><td> אומגה הנדסה בע&quot;מ </td><td> PX302-200GV </td><td></td></tr><tr><td> תא עומס מרכך </td><td> הדרן אלקטרוניקה, Inc </td><td> 4025-101 </td><td></td></tr><tr><td> רכישת נתונים (DAQ) Module </td><td> מדידה המיחשוב </td><td> PMD1608 </td><td></td></tr></tbody></table>

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

שסתום אבי העורקים, הנמצא בין החדר השמאלי לבין אבי העורקים, שמאפשר זרימת דם חד כיווני, מונע backflow לתוך החדר. שסתום אבי העורקים עלונים מורכבים תאים ביניים מושעה בתוך המטריצה ​​תאית (ECM) ו מכוסים monolayer תא האנדותל. השסתום עמיד סביבה קשים, דינמי חשוף כל הזמן גזירה, כפיפה, מתח, דחיסה. מחקרים הראו נגעים calcific ב שסתומים חולה להתרחש באזורים של לחץ מכני גבוה כתוצאה של הפרעה או נזק אנדותל מטריצה ​​ביניים 1-3. לפיכך, אין זה מפתיע כי מחקרים אפידמיולוגיים הראו לחץ דם גבוה להיות גורם סיכון המובילות תחילת המחלה שסתום אבי העורקים 4. האפשרות היחידה העומדת כיום לטיפול במחלה הוא החלפת המסתם כירורגית של המסתם הפגוע עם שסתום מכני או bioprosthetic 5. הבנה משופרת של הביולוגיה שסתום בתגובה מדגיש גופנית תעזור להבהיר את מנגנוני הפתוגנזה שסתום. בתורו, זה יכול לעזור בפיתוח של טיפולים לא פולשניים כגון התערבות מניעה או תרופות. Bioreactors פותחו מספר קודם ללמוד את mechanobiology של מסתמי הלב יליד או מהונדסים 6-9. Bioreactors pulsatile יש גם פותחו ללמוד מגוון רחב של רקמות, כולל 10 סחוס, עצם 11 ושלפוחית ​​השתן 12. מטרת עבודה זו היתה לפתח מערכת לחצים מחזורית שניתן להשתמש בו על מנת להבהיר את התגובה הביולוגית של עלונים שסתום אבי העורקים אל המון לחץ מוגבר. המערכת כללה תא אקרילי שבו למקום דגימות לייצר לחץ מחזורית, סולנואיד Viton הסרעפת שסתומים לשלוט בעיתוי של המחזור לחץ, מחשב כדי לשלוט מכשירים חשמליים. הלחץ היה פיקוח באמצעות מתמר הלחץ, את האות הותנה בעזרת מרכך תא העומס. תוכנית LabVIEW מוסדר את הלחץ באמצעות מכשיר אנלוגי משאבת אוויר דחוס לתוך המערכת בקצב המתאים. המערכת חיקה את רמות הלחץ הדינמי transvalvular הקשורים שסתום אבי העורקים, גל שן ראה המיוצר עלייה הדרגתית בלחץ, אופייני שיפוע הלחץ transvalvular כי קיים על פני המסתם במהלך דיאסטולה, ואחריו ירידה חדה בלחץ המתארות פתיחת שסתום התכווצות. התוכנית LabVIEW מותר למשתמשים לשלוט על עוצמת ותדירות לחץ מחזורית. המערכת הצליחה נושא דגימות רקמה לתנאי הלחץ פיזיולוגיים ופתולוגיים. מכשיר זה יכול לשמש כדי להגביר את הבנתנו כיצד מסתמי הלב להגיב לשינויים בסביבה מכני המקומית.

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

Bioreactor לחץ מחזורית מסוגל להעמיד שסתום רקמת לב לתנאי הלחץ פיזיולוגיים ופתולוגיים תוכנן. תוכנית LabVIEW מאפשר למשתמשים לשלוט על גודל הלחץ, משרעת ותדירות. מכשיר זה יכול לשמש כדי לחקור את mechanobiology של רקמת לב שסתום או תאים בודדים.

עיצוב של bioreactor לחץ על מחזורי Ex Vivo מחקר של מסתמי הלב אבי העורקים

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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15.7K Views.  Mississippi State University. Bioreactor לחץ מחזורית מסוגל להעמיד שסתום רקמת לב לתנאי הלחץ פיזיולוגיים ופתולוגיים תוכנן. תוכנית LabVIEW מאפשר למשתמשים לשלוט על גודל הלחץ, משרעת ותדירות. מכשיר זה יכול לשמש כדי לחקור את mechanobiology של רקמת לב שסתום או תאים בודדים.

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

Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization

Implantable microdevices are gaining significant attention for several biomedical applications1-4. Such devices have been made from a range of materials, each offering its own advantages and shortcomings5,6. Most prominently, due to the microscale device dimensions, a high modulus is required to facilitate implantation into living tissue. Conversely, the stiffness of the device should match the surrounding tissue to minimize induced local strain7-9. Therefore, we recently developed a new class of bio-inspired materials to meet these requirements by responding to environmental stimuli with a change in mechanical properties10-14. Specifically, our poly(vinyl acetate)-based nanocomposite (PVAc-NC) displays a reduction in stiffness when exposed to water and elevated temperatures (e.g. body temperature). Unfortunately, few methods exist to quantify the stiffness of materials in vivo15, and mechanical testing outside of the physiological environment often requires large samples inappropriate for implantation. Further, stimuli-responsive materials may quickly recover their initial stiffness after explantation. Therefore, we have developed a method by which the mechanical properties of implanted microsamples can be measured ex vivo, with simulated physiological conditions maintained using moisture and temperature control13,16,17. 
To this end, a custom microtensile tester was designed to accommodate microscale samples13,17 with widely-varying Young's moduli (range of 10 MPa to 5 GPa). As our interests are in the application of PVAc-NC as a biologically-adaptable neural probe substrate, a tool capable of mechanical characterization of samples at the microscale was necessary. This tool was adapted to provide humidity and temperature control, which minimized sample drying and cooling17. As a result, the mechanical characteristics of the explanted sample closely reflect those of the sample just prior to explantation.
The overall goal of this method is to quantitatively assess the in vivo mechanical properties, specifically the Young's modulus, of stimuli-responsive, mechanically-adaptive polymer-based materials. This is accomplished by first establishing the environmental conditions that will minimize a change in sample mechanical properties after explantation without contributing to a reduction in stiffness independent of that resulting from implantation. Samples are then prepared for implantation, handling, and testing (Figure 1A). Each sample is implanted into the cerebral cortex of rats, which is represented here as an explanted rat brain, for a specified duration (Figure 1B). At this point, the sample is explanted and immediately loaded into the microtensile tester, and then subjected to tensile testing (Figure 1C). Subsequent data analysis provides insight into the mechanical behavior of these innovative materials in the environment of the cerebral cortex.

Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization

A method is discussed by which the in vivo mechanical behavior of stimuli-responsive materials is monitored as a function of time. Samples are tested ex vivo using a microtensile tester with environmental controls to simulate the physiological environment. This work further promotes understanding the in vivo behavior of our material.

בדיקת Microtensile לסביבה מבוקרת של nanocomposites הפולימר מכאני-מסתגל ל<em&gt; לשעבר vivo</em&gt; אפיון

Implantable microdevices are gaining significant attention for several biomedical applications1-4. Such devices have been made from a range of materials, ...

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.

דוגמנות מטופל ספציפי של לב: אומדן של אורינטציות סיבי חדרית

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

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.

עיצוב של Bioreactor טוען מכונות Biaxial להנדסת רקמות

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.

מבצע של Bioreactor Benchtop

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.

אפיון של מערכות מורכבות באמצעות העיצוב של גישת ניסויים: ביטוי חלבון חלוף בטבק כמקרה מבחן

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.

מודל הלב Neonatal מציאותי אנטומית לשימוש ב- Neonatal סימולטורים החולה

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.

מיקרוסקופ אור גיליונות פלורסצנטיות לחקר הלב מאתר

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.

מודל לשעבר Vivo חדש על ההערכה של ביצועי חומרים הזרקה Submucosal אנדוסקופי

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.

אפיוני מכני biaxial של מסתמי הלב Atrioventricular

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

Imaging-Guided Bioreactor for Generating Bioengineered Airway Tissue

Repeated injury to airway tissue can impair lung function and cause chronic lung disease, such as chronic obstructive pulmonary disease. Advances in regenerative medicine and bioreactor technologies offer opportunities to produce lab-grown functional tissue and organ constructs that can be used to screen drugs, model disease, and engineer tissue replacements. Here, a miniaturized bioreactor coupled with an imaging modality that allows in situ visualization of the inner lumen of explanted rat trachea during in vitro tissue manipulation and&#160;culture is described. Using this bioreactor, the protocol demonstrates imaging-guided selective removal of endogenous cellular components while preserving the intrinsic biochemical features and ultrastructure of the airway tissue matrix. Furthermore, the delivery, uniform distribution, and subsequent prolonged culture of exogenous cells on the decellularized airway lumen with optical monitoring in situ are shown. The results highlight that the imaging-guided bioreactor can potentially be used to facilitate the generation of functional in vitro airway tissues.

The protocol describes an imaging-enabled bioreactor that allows the selective removal of the endogenous epithelium from the rat trachea and homogenous distribution of exogenous cells on the lumen surface, followed by long-term in vitro culture of the cell-tissue construct.

ביוריאקטור מונחה הדמיה ליצירת רקמת נתיב אוויר מהונדסת ביולוגית

Repeated injury to airway tissue can impair lung function and cause chronic lung disease, such as chronic obstructive pulmonary disease. Advances in ...