המחבר מודה ד&quot;ר ג&#39;ין גאו לסינתזה PGS, ד&quot;ר פיטר Crapo לדיון תובנה bioreactor עבור ההתקנה, בני הזוג. מוחמד Ezzelarab ו ווי וו עבור explanting הבבון עורקי הראש. מחקר זה מומן על ידי מענק מטעם מכון הבריאות הלאומי (R01 HL089658).

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	<li>The American Heart Association Statistics Committee Stroke Statistics Subcommittee. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=American+Heart+Association:+Heart+disease+and+stroke+statistics-2009+update.">American Heart Association: Heart disease and stroke statistics-2009 update.</a> Circulation. 119, 480-486 (2009).</li><li>Isenberg, B. C., Williams, C., Tranquillo, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small-diameter+artificial+arteries+engineered+in+vitro.">Small-diameter artificial arteries engineered in vitro.</a> Circ Res. 98, 25-35 (2006).</li><li>Conte, M. 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M., Gao, J., Wang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seamless+tubular+poly(glycerol+sebacate)+scaffolds:+high-yield+fabrication+and+potential+applications.">Seamless tubular poly(glycerol sebacate) scaffolds: high-yield fabrication and potential applications.</a> J Biomed Mater Res A. 86, 354-363 (2008).</li><li>Gao, J., Ensley, A. E., Nerem, R. M., Wang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly(glycerol+sebacate)+supports+the+proliferation+and+phenotypic+protein+expression+of+primary+baboon+vascular+cells.">Poly(glycerol sebacate) supports the proliferation and phenotypic protein expression of primary baboon vascular cells.</a> J Biomed Mater Res A. 83, 1070-1075 (2007).</li><li>Murphy, W. L., Dennis, R. G., Kileny, J. L., Mooney, D. 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E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+strain+induces+growth+of+vascular+smooth+muscle+cells+via+autocrine+action+of+PDGF.">Mechanical strain induces growth of vascular smooth muscle cells via autocrine action of PDGF.</a> J Cell Biol. 123, 741-747 (1993).</li><li>Leung, D. Y., Glagov, S., Mathews, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+stretching+stimulates+synthesis+of+matrix+components+by+arterial+smooth+muscle+cells+in+vitro.">Cyclic stretching stimulates synthesis of matrix components by arterial smooth muscle cells in vitro.</a> Science. 191, 475-477 (1976).</li><li>Kim, B. S., Nikolovski, J., Bonadio, J., Mooney, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+mechanical+strain+regulates+the+development+of+engineered+smooth+muscle+tissue.">Cyclic mechanical strain regulates the development of engineered smooth muscle tissue.</a> Nat Biotechnol. 17, 979-983 (1999).</li><li>Yang, J., Motlagh, D., Webb, A. R., Ameer, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+biphasic+elastomeric+scaffold+for+small-diameter+blood+vessel+tissue+engineering.">Novel biphasic elastomeric scaffold for small-diameter blood vessel tissue engineering.</a> Tissue Eng. 11, 1876-1886 (2005).</li><li>Stankus, J. J., Soletti, L., Fujimoto, K., Hong, Y., Vorp, D. A., Wagner, W. 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אין ניגודי אינטרסים הכריז.

טכניקת ייצור באמצעות אלסטומר מתכלה המתוארים כאן יש כמה תכונות. (1) השתמשנו חומצה היאלורונית (HA) כמו לשחרר עובש. מאז HA הוא מסיס במים, הפיגום השתחרר בקלות לאחר שריה אותו לתוך מים עובש הזכוכית. בדו&quot;ח זה, השתמשנו 1.0 wt / כרך% של פתרון HA בגלל ריכוז נמוך (&lt;0.5 wt / כרך%) של הפתרון הוא לא צמיג זורם למטה כל כך מהר כשאנחנו לשפוך אותו על גבי צינורות זכוכית. כדי פתרון HA מעיל אחיד, אנו התהפך צינור הזכוכית כאשר הפתרון הנמיכה את החלק התחתון של הצינור וחזר על שלב זה. זה ציפוי HA הוא קריטי בהליך הייצור שלנו לשחרור פיגומים הסופי. (2) השתמשנו חום כויץ (HS) שרוול עבור שמירה מלחים בצינור הזכוכית. מאז היו מלחים בצפיפות במרחב שבין הקיר הפנימי של צינורות זכוכית השרוול HS, שרוול HS שמר מלחים לאחר הסרת mandrel וטבעת PTFE בחלקו התחתון של הצינור. אנחנו יכולים להסיר שרוול HS בקלות על ידי הצבת את התבנית לתנור על 120 מעלות צלזיוס למשך 5 דקות, ולאחר מכן לקבל תבניות מלח צינורי. (3) השתמשנו בשיטה היתוך מלח. זה ידוע היטב כי היתוך שיטה מלח יכולה לשפר interconnectivity נקבוביות תכונות מכניות על ידי שינוי זמן היתוך 10. יתר על כן, מאז השתמשנו PGS, מאקרו הנקבוביות יוצרו על ידי חלקיקי מלח בתהליך שטיפת, ואילו המיקרו נקבוביות נוצרו ככל הנראה על ידי אדי גליצרול נוצרו במהלך PGS ריפוי כפי שתואר קודם לכן 11. לכן, בשיטה זו יש פוטנציאל לייצר פיגומים צינורי נקבובי עם מאקרו שונים מיקרו מבנים על ידי שינוי חלקיקי מלח, כמו גם בריפוי מצב PGS. מיזוג מכני מ bioreactor סיפקה זלוף תזרים pulsatile (מקסימום אומרת זרימה = 14 מ&quot;ל / דקה, הלחץ גזירה מרבי = 15.3 Dyne / 2 ס&quot;מ, תדירות = 0.5-1.7 הרץ) ו - פיזיולוגית הלחץ רלוונטי עם הפיגום PGS, אשר הובילה SMC צמיחה אוריינטציה (איור 4). תוצאות אלו עולות בקנה אחד עם מחקרים קודמים דיווח כי למתוח מחזורית בתדר זה ​​הלחץ גזירה מגבירה SMC התפשטות 12, ECM ייצור החלבון 13,14. בנוסף לצמיחה SMC והכיוון, PGS לבנות נתמך ECM ייצור חלבון, במיוחד מאורגן circumferentially סיבים אלסטיים (איור 5) בתוך התרבות 3-שבוע bioreactor. כמה מחקרים באמצעות אלסטומרי פיגום כמבנה קטן בקוטר העורקים הראו חוזק מכני והלחץ פרץ להשוות העורקים יליד 15, ושילוב SMC המהירה פיגומים תואם באמצעות בקבוק טווה 16,17, בעוד סיבים אלסטיים לא נמצאו מבנים אלה. התוצאות שלנו מראים כי distension רדיאלי מחזורית מן bioreactor השתפר הולכת אותות מכני יעיל יותר SMCs ב PGS הפיגום, אשר ככל הנראה תרמו ואלסטין סינתזה הארגון. מאז SMCs כלי הדם היו רק תאים שייצרו חלבונים ECM של האנדותל שלנו, הגישה שקט ולשפר את חוזק מכני יש צורך לפתח מוצלח קלינית בקוטר קטן בונה העורקים. יש לנו דיווח כי לתאי אנדותל שיתוף תרבותי עם SMCs שנוצר monolayer ומחוברות ותמך חלבון ביטוי פנוטיפ בתנאים התרבות שלנו ומיזוג מכני 9. לכן, בהתבסס על הגישה שלנו המתואר כאן, שינוי של שיתוף התרבות תנאי הניסוי יהיה הצעד הבא כדי לשפר את הפונקציות של המבנים כתוצאה וליצור nonthrombogenic, החזקה, ואת עורקי תואם לבנות דומה העורקים הילידים.

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><th> שם מגיב </th><th> חברה </th><th> מספר קטלוגי </th></tr><tr><td> חומצה היאלורונית מלח נתרן </td><td> סיגמא אולדריץ </td><td> H7630 </td></tr><tr><td> Tetrahydrofuran </td><td> סיגמא אולדריץ </td><td> 401757 </td></tr><tr><td> MCDB 131 </td><td> Mediatech </td><td> 15-100-CV </td></tr><tr><td> בסרום שור עוברית </td><td> Lonza </td><td> BW14-502F </td></tr><tr><td> L-גלוטמין </td><td> Mediatech </td><td> 25-005-CV </td></tr><tr><td> חומצה אסקורבית </td><td> פישר סיינטיפיק </td><td> A62-500 </td></tr><tr><td> לאנטיביוטיקה antimycotic פתרון </td><td> Mediatech </td><td> 30-004-CI </td></tr><tr><td> בופר פוספט (PBS) </td><td> Mediatech </td><td> 21-031-CV </td></tr><tr><td> רקמות-Tek מתחם טמפרטורה אופטימלית חיתוך, 4583 </td><td> סאקורה Finetek </td><td> 25608-930 </td></tr></tbody></table>

elastomeric pgs scaffolds in arterial tissue engineering

מחלות לב וכלי דם הוא אחד הגורם המוביל לתמותה בארה&quot;ב במיוחד, מחלת לב כלילית עולה עם האוכלוסייה המזדקנת והשמנה הגדלת 1. נכון לעכשיו, ניתוח מעקפים באמצעות כלי עצמיים, allografts, ואת שתלי סינתטי ידועים כמו נפוץ תחליפי עורקים 2. עם זאת, שתלי אלה יש יישומים מוגבלים כאשר הקוטר הפנימי של העורקים הוא פחות מ 6 מ&quot;מ בשל זמינות נמוכה, סיבוכים טרומבוטיים, התאמה תאימות היפרפלזיה intimal מאוחר 3,4. כדי להתגבר על המגבלות האלה, הנדסת רקמות יושם בהצלחה כחלופה מבטיח לפתח קטן בקוטר בונה עורקי כי הם nonthrombogenic, חזקים, ותואמת. מחקרים קודמים מספר פיתחו בקוטר קטן בונה עורקי עם מבנה תלת lamellar, תכונות מכניות מעולה הלחץ פרץ להשוות העורקים יליד 5,6. למרות חוזק מתיחה גבוה ולחץ פרץ ידי הגברת ייצור הקולגן מחומר נוקשה או סדין בתא הגרדום, המבנים הללו עדיין ייצור האלסטין ציות נמוך, וזה בעיה רצינית כדי לגרום לכישלון השתל לאחר ההשתלה. לאור בעיות אלו, אנו משערים כי elastometric ביולוגי בשילוב עם מיזוג מכני תספק גמישות והתנהגות אותות מכני יעיל יותר לתאי הדם, אשר להגביר את ייצור תאי מטריקס ותמיכה אוריינטציה הסלולר. מטרת דו&quot;ח זה היא להציג את טכניקת ייצור של פיגומים צינורי נקבוביים מיזוג מכני דינמי והחלתן על הנדסת רקמות העורקים. השתמשנו אלסטומר מתכלה, פולי (sebacate גליצרול) (PGS) 7 בודה פיגומים צינורי נקבובי מן השיטה היתוך מלח. למבוגרים חלקה העיקרי הבבון שריר תאים (SMCs) היו זורעים על לומן של פיגומים, אשר בתרבית bioreactor תוכנן שלנו לזרום pulsatile למשך 3 שבועות. פיגומים PGS היה עקבי עובי ומופץ באופן אקראי מאקרו ומיקרו הנקבוביות. מיזוג מכונות מ bioreactor תזרים pulsatile נתמך SMC התמצאות משופרת ייצור ECM של פיגומים. התוצאות מראות כי פיגומים אלסטומרי ומיזוג מכני של התרבות bioreactor עשוי להיות שיטה מבטיחה עבור הנדסת רקמות העורקים.

Watch this Scientific Journal Video about Elastomeric PGS Scaffolds in Arterial Tissue Engineering at JoVE.com

Elastomeric PGS Scaffolds in Arterial Tissue Engineering

PGS אלסטומרי פיגומים עם כלי הדם לתאי שריר חלק בתרבית bioreactor זרימה pulsatile עלול להוביל בקוטר קטן בונה מבטיח עורקי עם ייצור ECM יליד בתקופה התרבות קצר יחסית.

PGS אלסטומרי פיגומים להנדסת רקמות העורקים

Cardiovascular disease is one of the leading cause of mortality in the US and especially, coronary artery disease increases with an aging population and ...

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Research

JoVE Journal

Bioengineering

15.5K Views.  University of Pittsburgh. PGS אלסטומרי פיגומים עם כלי הדם לתאי שריר חלק בתרבית bioreactor זרימה pulsatile עלול להוביל בקוטר קטן בונה מבטיח עורקי עם ייצור ECM יליד בתקופה התרבות קצר יחסית.

Video: Elastomeric PGS Scaffolds in Arterial Tissue Engineering

Engineering Biological-Based Vascular Grafts Using a Pulsatile Bioreactor

Much effort has been devoted to develop and advance the methodology to regenerate functional small-diameter arterial bypasses. In the physiological environment, both mechanical and chemical stimulation are required to maintain the proper development and functionality of arterial vessels1,2.
Bioreactor culture systems developed by our group are designed to support vessel regeneration within a precisely controlled chemo-mechanical environment mimicking that of native vessels. Our bioreactor assembly and maintenance procedures are fairly simple and highly repeatable3,4. Smooth muscle cells (SMCs) are seeded onto a tubular polyglycolic acid (PGA) mesh that is threaded over compliant silicone tubing and cultured in the bioreactor with or without pulsatile stimulation for up to 12 weeks. There are four main attributes that distinguish our bioreactor from some predecessors. 1) Unlike other culture systems that simulate only the biochemical surrounding of native blood vessels, our bioreactor also creates a physiological pulsatile environment by applying cyclic radial strain to the vessels in culture. 2) Multiple engineered vessels can be cultured simultaneously under different mechanical conditions within a controlled chemical environment. 3) The bioreactor allows a mono layer of endothelial cells (EC) to be easily coated onto the luminal side of engineered vessels for animal implantation models. 4) Our bioreactor can also culture engineered vessels with different diameter size ranged from 1 mm to 3 mm, saving the effort to tailor each individual bioreactor to fit a specific diameter size. 
The engineered vessels cultured in our bioreactor resemble native blood vessels histologically to some degree. Cells in the vessel walls express mature SMC contractile markers such as smooth muscle myosin heavy chain (SMMHC)3. A substantial amount of collagen is deposited within the extracellular matrix, which is responsible for ultimate mechanical strength of the engineered vessels5. Biochemical analysis also indicates that collagen content of engineered vessels is comparable to that of native arteries6. Importantly, the pulsatile bioreactor has consistently regenerated vessels that exhibit mechanical properties that permit successful implantation experiments in animal models3,7. Additionally, this bioreactor can be further modified to allow real-time assessment and tracking of collagen remodeling over time, non-invasively, using a non-linear optical microscopy (NLOM)8. To conclude, this bioreactor should serve as an excellent platform to study the fundamental mechanisms that regulate the regeneration of functional small-diameter vascular grafts.

Our group has developed a bioreactor culture system that mimics the physiological pulsatile stresses of the cardiovascular system to regenerate implantable small-diameter vascular grafts.

הנדסה ביולוגית המבוססת דם שתלי שימוש bioreactor pulsatile

Much effort has been devoted to develop and advance the methodology to regenerate functional small-diameter arterial bypasses. In the physiological ...

Engineering a Bilayered Hydrogel to Control ASC Differentiation

Natural polymers over the years have gained more importance because of their host biocompatibility and ability to interact with cells in vitro and in vivo. An area of research that holds promise in regenerative medicine is the combinatorial use of novel biomaterials and stem cells. A fundamental strategy in the field of tissue engineering is the use of three-dimensional scaffold (e.g., decellularized extracellular matrix, hydrogels, micro/nano particles) for directing cell function. This technology has evolved from the discovery that cells need a substrate upon which they can adhere, proliferate, and express their differentiated cellular phenotype and function 2-3. More recently, it has also been determined that cells not only use these substrates for adherence, but also interact and take cues from the matrix substrate (e.g., extracellular matrix, ECM)4. Therefore, the cells and scaffolds have a reciprocal connection that serves to control tissue development, organization, and ultimate function. Adipose-derived stem cells (ASCs) are mesenchymal, non-hematopoetic stem cells present in adipose tissue that can exhibit multi-lineage differentiation and serve as a readily available source of cells (i.e. pre-vascular endothelia and pericytes). Our hypothesis is that adipose-derived stem cells can be directed toward differing phenotypes simultaneously by simply co-culturing them in bilayered matrices1. Our laboratory is focused on dermal wound healing. To this end, we created a single composite matrix from the natural biomaterials, fibrin, collagen, and chitosan that can mimic the characteristics and functions of a dermal-specific wound healing ECM environment.

This protocol focuses on utilizing the inherent ability of stem cells to take cue from their surrounding extracellular matrix and be induced to differentiate into multiple phenotypes. This methods manuscript extends our description and characterization of a model utilizing a bilayered hydrogel, composed of PEG-fibrin and collagen, to simultaneously co-differentiate adipose-derived stem cells1.

הנדסת Hydrogel Bilayered לשלוט בידול ASC

Natural polymers over the years have gained more importance because of their host biocompatibility and ability to interact with cells in vitro and in ...

Electrospun Fibrous Scaffolds of Poly(glycerol-dodecanedioate) for Engineering Neural Tissues From Mouse Embryonic Stem Cells

For tissue engineering applications, the preparation of biodegradable and biocompatible scaffolds is the most desirable but challenging task. &#160;Among the various fabrication methods, electrospinning is the most attractive one due to its simplicity and versatility. Additionally, electrospun nanofibers mimic the size of natural extracellular matrix ensuring additional support for cell survival and growth. This study showed the viability of the fabrication of long fibers spanning a larger deposit area for a novel biodegradable and biocompatible polymer named&#160;poly(glycerol-dodecanoate) (PGD)1 by using a newly designed collector for electrospinning. PGD exhibits unique elastic properties with similar mechanical properties to nerve tissues, thus it is suitable for neural tissue engineering applications. The synthesis and fabrication set-up for making fibrous scaffolding materials was simple, highly reproducible, and inexpensive. In biocompatibility testing, cells derived from mouse embryonic stem cells could adhere to and grow on the electrospun PGD fibers. In summary, this protocol provided a versatile fabrication method for making PGD electrospun fibers to support the growth of mouse embryonic stem cell derived neural lineage cells.

Electrospun Fibrous Scaffolds of Polyglycerol-dodecanedioate for Engineering Neural Tissues From Mouse Embryonic Stem Cells

Synthesis and fabrication of electrospun long fibers spanning a larger deposit area via a newly designed collector from a novel biodegradable polymer named poly(glycerol-dodecanoate) (PGD) was reported. The fibers were able to support the growth of cells derived from mouse pluripotent stem cells.

Electrospun סיבי פיגומים של פולי (גליצרול-dodecanedioate) להנדסה עצבית רקמות מתאי גזע עובריים בעכבר

For tissue engineering applications, the preparation of biodegradable and biocompatible scaffolds is the most desirable but challenging task. &#160;Among ...

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.

Here, we present a protocol to generate tissue engineered vessel grafts that are functional for grafting into mice by double seeding partially induced pluripotent stem cell (PiPSC) - derived smooth muscle cells and PiPSC - derived endothelial cells on a decellularized vessel scaffold bioreactor.

דור והארכת כלי רקמות מהונדסות במודל עכבר

The construction of vascular conduits is a fundamental strategy for surgical repair of damaged and injured vessels resulting from cardiovascular diseases. ...

Composite Scaffolds of Interfacial Polyelectrolyte Fibers for Temporally Controlled Release of Biomolecules

Various scaffolds used in tissue engineering require a controlled biochemical environment to mimic the physiological cell niche. Interfacial polyelectrolyte complexation (IPC) fibers can be used for controlled delivery of various biological agents such as small molecule drugs, cells, proteins and growth factors. The simplicity of the methodology in making IPC fibers gives flexibility in its application for controlled biomolecule delivery. Here, we describe a method of incorporating IPC fibers into two different polymeric scaffolds, hydrophilic polysaccharide and hydrophobic polycaprolactone, to create a multi-component composite scaffold. We showed that IPC fibers can be easily embedded into these polymeric structures, enhancing the capability for sustained release and improved preservation of biomolecules. We also created a composite polymeric scaffold with topographical cues and sustained biochemical release that can have synergistic effects on cell behavior. Composite polymeric scaffolds with IPC fibers represent a novel and simple method of recreating the cellular niche.

Scaffolds for tissue engineering need to recapitulate the complex biochemical and biophysical microenvironment of the cellular niche. Here, we show the use of interfacial polyelectrolyte complexation fibers as a platform to create composite, multi-component polymeric scaffolds with sustained biochemical release.

פיגומים מורכבים של סיבי Interfacial polyelectrolyte לשחרור מבוקר באופן זמני של מולקולות ביולוגיות

Various scaffolds used in tissue engineering require a controlled biochemical environment to mimic the physiological cell niche. Interfacial ...

Synthesis of Thermogelling Poly(N-isopropylacrylamide)-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering

Injectable biomaterials are defined as implantable materials that can be introduced into the body as a liquid and solidify in situ. Such materials offer the clinical advantages of being implanted minimally invasively and easily forming space-filling solids in irregularly shaped defects. Injectable biomaterials have been widely investigated as scaffolds for tissue engineering. However, for the repair of certain load-bearing areas in the body, such as the intervertebral disc, scaffolds should possess adhesive properties. This will minimize the risk of dislocation during motion and ensure intimate contact with the surrounding tissue, providing adequate transmission of forces. Here, we describe the preparation and characterization of a scaffold composed of thermally sensitive poly(N-isopropylacrylamide)-graft-chondroitin sulfate (PNIPAAM-g-CS) and alginate microparticles. The PNIPAAm-g-CS copolymer forms a viscous solution in water at RT, into which alginate particles are suspended to enhance adhesion. Above the lower critical solution temperature (LCST), around 30 &#176;C, the copolymer forms a solid gel around the microparticles. We have adapted standard biomaterials characterization procedures to take into account the reversible phase transition of PNIPAAm-g-CS. Results indicate that the incorporation of 50 or 75 mg/ml&#160;alginate particles into 5% (w/v) PNIPAAm-g-CS solutions quadruple the adhesive tensile strength of PNIPAAm-gCS alone (p&#60;0.05). The incorporation of alginate microparticles also significantly increases swelling capacity of PNIPAAm-g-CS (p&#60;0.05), helping to maintain a space-filling gel within tissue defects. Finally, results of the in vitro toxicology assay kit, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) and Live/Dead viability assay indicate that the adhesive is capable of supporting the survival and proliferation of encapsulated Human Embryonic Kidney (HEK) 293 cells over 5 days.

Synthesis of Thermogelling PolyN-isopropylacrylamide-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering

An injectable tissue engineering scaffold composed of poly(N-isopropylacrylamide)-graft-chondroitin sulfate (PNIPAAm-g-CS)-containing alginate microparticles was prepared. The adhesive strength, swelling properties and in vitro biocompatibility are analyzed in this study. The characterization techniques developed here may be applicable to other thermogelling systems.

סינתזה של Thermogelling midi (N-isopropylacrylamide) מרוכבים -graft-כונדרואיטין סולפט עם אלגינט microparticles עבור הנדסת רקמות

Injectable biomaterials are defined as implantable materials that can be introduced into the body as a liquid and solidify in situ. Such materials offer ...

A Multi-Cue Bioreactor to Evaluate the Inflammatory and Regenerative Capacity of Biomaterials under Flow and Stretch

The use of resorbable biomaterials to induce regeneration directly in the body is an attractive strategy from a translational perspective. Such materials induce an inflammatory response upon implantation, which is the driver of subsequent resorption of the material and the regeneration of new tissue. This strategy, also known as in situ tissue engineering, is pursued to obtain cardiovascular replacements such as tissue-engineered vascular grafts. Both the inflammatory and the regenerative processes are determined by the local biomechanical cues on the scaffold (i.e., stretch and shear stress). Here, we describe in detail the use of a custom-developed bioreactor that uniquely enables the decoupling of stretch and shear stress on a tubular scaffold. This allows for the systematic and standardized evaluation of the inflammatory and regenerative capacity of tubular scaffolds under the influence of well-controlled mechanical loads, which we demonstrate on the basis of a dynamic co-culture experiment using human macrophages and myofibroblasts. The key practical steps in this approach&#8212;the construction and setting up of the bioreactor, preparation of the scaffolds and cell seeding, application and maintenance of stretch and shear flow, and sample harvesting for analysis&#8212;are discussed in detail.

The goal of this protocol is to execute a dynamic co-culture of human macrophages and myofibroblasts in tubular electrospun scaffolds to investigate material-driven tissue regeneration, using a bioreactor which enables the decoupling of shear stress and cyclic stretch.

ביו-ריאקטור רב-שלבי להערכת היכולת הדלקתית וההתחדשותית של ביו-חומרים תחת זרימה ומתיחות

The use of resorbable biomaterials to induce regeneration directly in the body is an attractive strategy from a translational perspective. Such materials ...

Engineering

A Facile and Eco-friendly Route to Fabricate Poly(Lactic Acid) Scaffolds with Graded Pore Size

Over the recent years, functionally graded scaffolds (FGS) gaineda crucial role for manufacturing of devices for tissue engineering. The importance of this new field of biomaterials research is due to the necessity to develop implants capable of mimicking the complex functionality of the various tissues, including a continuous change from one structure or composition to another. In this latter context, one topic of main interest concerns the design of appropriate scaffolds for bone-cartilage interface tissue. In this study, three-layered scaffolds with graded pore size were achieved by melt mixing poly(lactic acid) (PLA), sodium chloride (NaCl) and polyethylene glycol (PEG). Pore size distributions were controlled by NaCl granulometry and PEG solvation. Scaffolds were characterized from a morphological and mechanical point of view. A correlation between the preparation method, the pore architecture and compressive mechanical behavior was found. The interface adhesion strength was quantitatively evaluated by using a custom-designed interfacial strength test. Furthermore, in order to imitate the human physiology, mechanical tests were also performed in phosphate buffered saline (PBS) solution at 37 &#176;C. The method herein presented provides a high control of porosity, pore size distribution and mechanical performance, thus offering the possibility to fabricate three-layered scaffolds with tailored properties by following a simple and eco-friendly route.

A Facile and Eco-friendly Route to Fabricate PolyLactic Acid Scaffolds with Graded Pore Size

In this work, poly(lactic acid)/polyethylene glycol (PLA/PEG) scaffolds were prepared by using a combination of melt mixing and selective leaching. The method herein discussed permitted to develop three-layer scaffolds by highly controlling both porosity and pore size. The mechanical properties were also evaluated in a physiological environment.

קליל ידידותי לסביבת כביש לפברק פולי (החומצה לקטית) פיגומים עם גודל מדורג נקבובי

Over the recent years, functionally graded scaffolds (FGS) gaineda crucial role for manufacturing of devices for tissue engineering. The importance of ...

Nondestructive Monitoring of Degradable Scaffold-Based Tissue-Engineered Blood Vessel Development Using Optical Coherence Tomography

Engineered vascular grafts with structural and mechanical properties similar to natural blood vessels are expected to meet the growing demand for arterial bypass. Characterization of the growth dynamics and remodeling process of degradable polymer scaffold-based tissue-engineered blood vessels (TEBVs) with pulsatile stimulation is crucial for vascular tissue engineering. Optical imaging techniques stand out as powerful tools for monitoring vascularization of engineered tissue enabling high-resolution imaging in real-time culture. This paper demonstrates a nondestructive and fast real-time imaging strategy to monitor the growth and remodeling of TEBVs in long-term culture by using optical coherence tomography (OCT). Geometric morphology is evaluated, including vascular remodeling process, wall thickness, and comparison of TEBV thickness in different culture time points and presence of pulsatile stimulation. Finally, OCT provides practical possibilities for real-time observation of the degradation of polymer in the reconstructing tissues under pulsatile stimulation or not and in each vessel segment, by compared with the assessment of polymer degradation using scanning electron microscopic(SEM) and polarized microscope.

A step by step protocol for nondestructive and long-period monitoring the process of vascular remodeling and scaffold degradation in real-time culture of biodegradable polymeric scaffold-based tissue-engineered blood vessels with pulsatile stimulation using optical coherence tomography is described here.

ניטור לא הורסות של פיתוח מתכלה מבוססי לגרדום רקמות מהונדסים כלי דם באמצעות טומוגרפיה אופטית קוהרנטית

Engineered vascular grafts with structural and mechanical properties similar to natural blood vessels are expected to meet the growing demand for arterial ...

Core/shell Printing Scaffolds For Tissue Engineering Of Tubular Structures

Three-dimensional (3D) printing of core/shell filaments allows direct fabrication of channel structures with a stable shell that is cross-linked at the interface with a liquid core. The latter is removed post-printing, leaving behind a hollow tube. Integrating an additive manufacturing technique (like the one described here with tailor-made [bio]inks, which structurally and biochemically mimic the native extracellular matrix [ECM]) is an important step towards advanced tissue engineering. However, precise fabrication of well-defined structures requires tailored fabrication strategies optimized for the material in use. Therefore, it is sensible to begin with a set-up that is customizable, simple-to-use, and compatible with a broad spectrum of materials and applications. This work presents an easy-to-manufacture core/shell nozzle with luer-compatibility to explore core/shell printing of woodpile structures, tested with a well-defined, alginate-based scaffold material formulation.

Presented here is a simple-to-use, core/shell, three-dimensional bioprinting set-up for one-step fabrication of hollow scaffolds, suitable for tissue engineering of vascular and other tubular structures.

ליבה/פגז הדפסה פיגומים קפלים להנדסת רקמות של מבנים צינורי

Three-dimensional (3D) printing of core/shell filaments allows direct fabrication of channel structures with a stable shell that is cross-linked at the ...