Yazarlar minnetle yapıştırıcı çekme test protokolünün geliştirilmesi Dr. Jennifer Kadlowec yardım kabul etmek istiyorum. Bu yayında bildirilen Araştırma Artrit ve Kas-iskelet ve Cilt Hastalıkları Ulusal Enstitüsü ve Ödül Numarası 1R15 AR 063920-01 altında Biyomedikal Görüntüleme ve Ulusal Sağlık Enstitüleri Biyomühendislik Ulusal Enstitüsü tarafından desteklenmiştir. Içeriği sadece yazarların sorumluluğundadır ve mutlaka Ulusal Sağlık Enstitüleri resmi görüşlerini temsil etmemektedir.

Yazarlar ifşa hiçbir şey yok.

hidrojel mikropartikül kompozit sentezleme ve yapıştırıcı gücü değerlendirmek, yetenek ve hücresel biyouyumluluk şişme birkaç kritik adımlar vardır. PNIPAAm-g-CS serbest radikal polimerizasyonu kondroitin sülfat başarılı methacrylation monomer bileşenlerinin tam çözülmesini, ve oksijensiz reaksiyon koşulları gerektirir. Yerli intervertebral disk dokusunun 29 benzer mekanik özelliklere sahip kopolimerler üretmek için, önceki çalışmada, gösterilmiştir, çünkü reaksiyon karı?...

Enjekte edilebilir Biyo materyaller uygun bir sıvı olarak vücuda verilen ve yerinde katılaşmaya edilebilir olanlardır. Bu tür malzemeler onlar hücreler 5 için üç boyutlu geçici ekstraselüler matriks olarak etkilenen sitede 1-4 ve hareket için kapsüllü hücreleri sunmak için kullanılan rejeneratif tıp, yaygın uygulanmıştır. implantasyon için cerrahi işlemler, minimal invaziv ve katı faz düzensiz özel boyutlu implantlar için ihtiyacı ortadan kaldırarak, doku defektleri şeklinde dolgu çünkü hasta için, enjektabl biyomateryaller avantajlıdır. Enjekte edilebilirlik çeşitli mekanizmalar aracılığıyla sağlanabilir. Dış faktörler, pH gibi hücreler ve biyolojik olarak aktif moleküllerin 6-8 kapsülleyen jeller oluşturmak için bir tetikleyici olarak incelenmiştir. Ancak, pH tüm fizyolojik ortamlarda kullanmak için en uygun tetikleyici olmayabilir. Başka geleneksel alternaenjekte edilebilirliği ulaşmak için tive yerinde kimyasal polimerizasyonu veya çapraz bağlantı kullanmaktadır. Bir grup, amonyum persülfat ve N, N, N &#39;, N&#39; tetrametiletilendiamin oluşan suda çözünür bir redoks sistemi geliştirilmiştir ve polietilen glikol ve poli (propilen), 9,10 glikol oluşan makromerleri reaksiyona sokmak için kullanılır. Zan ve ark., 11, gelişmiş enjekte çitosan polivinilalkol ağları glutaraldehit ile çapraz bağlanmış. Bu gibi sistemlerde, reaktif bileşenlerin sitotoksisitesi, özellikle hücre kapsülleme ile ilgili uygulamalar için, göz önünde bulundurulmalıdır. Ayrıca, ekzotermik polimerizasyon polimerik kemik 12,13 çimentolar için rapor edilmiştir çevreleyen doku, uzlaşmaya yeterince yüksek sıcaklıklara üretmek olabilir. Yine başka enjekte edilebilir polimer sistemleri tetikleyici sıcaklık ile sıvıdan katı hale gelen bir değişiklik sergilediği geliştirilmiştir. thermogelling sistemleri olarak bilinen bu aqueo vardırUS in situ oluşumu 14 elde etmek için kimyasal uyarıcı monomerler, veya çapraz bağlayıcı maddeler gerektirmeyen polimer solüsyonları. Bunun yerine, genellikle fizyolojik sıcaklığa yakın oluşan bir faz geçişi, bir fiziksel çapraz bağları olan üç boyutlu bir ağın oluşumuna neden olur. Pluronic F127 olarak poloksamerler ilaç dağıtım 15-17 ve hücre kapsülleme 18,19 thermogelling için en çok çalışılan polimerler arasında yer almaktadır. Bununla birlikte, iyi Bu jeller, fizyolojik koşullar altında kararlılık eksikliği olduğu kabul edilmektedir. Çalışmalar zincir uzatıcı 20 veya kimyasal çapraz bağlayıcı 21,22 kullanarak artan istikrar göstermiştir. Bununla birlikte, bu reaktiflerin kullanımı, hücre kapsüllenmesi için malzeme potansiyelini sınırlamaktadır. Poli (N-izopropil akrilamid) doku mühendisliği ve ilaç teslimat 14 önemli ilgi görmüştür sentetik thermogelling polimerdir. poli sulu çözeltiler (N-izopropilylacrylamide) (PNIPAAm), bir düşük kritik çözelti sıcaklığı (LCST&#39;nin) gösteren, tipik olarak yaklaşık 32 meydana gelen - 34 ° C 23,24. LCST&#39;nin altında, su PNIPAAm zincirleri nemlendirir. Geçiş sıcaklığının üstünde, polimer zehirli monomer veya çapraz bağlayıcı kullanılmadan dramatik faz ayrılması 25-27 ve bir katı jel oluşumu ile sonuçlanarak, hidrofobik hale gelir. Ancak, PNIPAAm homopolimerler zayıf elastik özellikler sergiler nedeniyle hidrofobiklik 28 fizyolojik sıcaklıkta az su tutun. Bu çalışmada, enzimatik degradasyon 29 anti-enflamatuar aktivite 30,31, ve artan su ve besin emilimi 32 potansiyel sunmaktadır PNIPAAm ağı içine kovalent kondroitin sülfat dahil seçin. CS PNIPAAm kopolimerleri aşılanmış kopolimere (PNIPAAm-g-CS) oluşturulması için metakrilat-işlevselleştirilmiş CS mevcudiyetinde monomer NIPAAm polimerleştirilmesiyle laboratuvarımızda hazırlandı. beckopolimerin, düşük çapraz bağlanma yoğunluğu ause, PNIPAAm-g-CS bağlı LCST&#39;nin 29, oda sıcaklığında su içinde yapışkan bir çözelti ve fizyolojik sıcaklıkta elastik bir jel oluşturur. polimer çözeltileri nedeniyle geçiş geri dönüşümlü tekrar LCST&#39;nin altında soğutma ile akışkan hale gelir. Bu PNIPAAm-g-CS, mekanik uygun olabilir özellikleri, parçalanabilirliği, insan embriyonik böbrek (HEK) hücre proliferasyonu ile 293 hücreleri 29, bir doku mühendisliği iskelesi olarak işlev potansiyeline sahip olduğunu göstermiştir. Ancak, bu tür intervertebral disk gibi belirli yük taşıyan alanlarda, doku mühendisliği iskeleleri çıkığı 33 riskini ortadan kaldırmak için çevredeki disk dokusu ile önemli bir arayüz oluşturmak için yeteneğine sahip olmalıdır. Bu arayüz, implant ve doku 33 arasındaki ara yüzey boyunca kuvvet yeterli aktarımı için de gereklidir. Çalışmalarımızın, biz askıya almış birlginate PNIPAAm-g-CS sulu çözeltiler içinde mikropartikülleri ve jelasyon doku 34 çevreleyen yapışma sağlamak mikropartiküller, lokalize olduğu bulunmuştur. Bu yazıda thermogelling, yapışkan polimer hazırlanması için adımları özetlemektedir. canlılığı için standart biyomateryaller karakterizasyonu, hücre görüntüleme teknikleri ve tahliller dikkate polimerin sıcaklık duyarlılığı ve faz geçiş reversibilite almaya adapte edilmiştir. Bu yazıda anlatılan enjektabl polimer Bu yazıda tarif edilenler dışında ilaç dağıtım ve doku mühendisliği uygulamaları için geniş bir potansiyele sahiptir. Ayrıca, burada açıklanan karakterizasyon yöntemleri diğer thermogelling sistemlere uygulanabilir.

<table border="0" cellpadding="0" cellspacing="0" width="885">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">N-isopropylacrylamide, 99%, pure, stabilized</td>
			<td style="width:164px;">Acros Organics</td>
			<td style="width:120px;">2210-25-5</td>
			<td style="width:347px;">Refrigerate and remove stabilier with hexane</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Chondroitin sulfate A sodium salt (from bovine trachea)</td>
			<td style="width:164px;">Sigma-Aldrich</td>
			<td style="width:120px;">39455-18-0</td>
			<td style="width:347px;">Refrigerate</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Hexanes</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">H302-4</td>
			<td style="width:347px;">Store in a flammable cabinet</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">50% (w/w) sodium hydroxide</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">SS254-1</td>
			<td style="width:347px;">Caustic in nature</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Methacrylic anhydride</td>
			<td style="width:164px;">Sigma-Aldrich</td>
			<td style="width:120px;">276685</td>
			<td style="width:347px;">Strong fumes; use in a fume hood</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Acetone</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">A18-4</td>
			<td style="width:347px;">Chill in a refrigerator prior to use</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Nitrogen Gas</td>
			<td style="width:164px;">Praxair</td>
			<td style="width:120px;">7727-37-9</td>
			<td style="width:347px;">Part Number: NI 4.8, cylinder style T, 99.998% pure nitrogen (Argon may be used as an alternative inert gas)</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Tetramethylethylenediamine, 99% extra pure</td>
			<td style="width:164px;">Acros Organics</td>
			<td style="width:120px;">110-18-9</td>
			<td style="width:347px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Ammonium persulfate</td>
			<td style="width:164px;">Sigma Aldrich</td>
			<td style="width:120px;">A3678</td>
			<td style="width:347px;">Hygroscopic and degrades in the presence of water</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Phosphate buffered saline tablets</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">BP2944</td>
			<td style="width:347px;">Keep dry</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Alginic acid, sodium salt</td>
			<td style="width:164px;">Acros Organics</td>
			<td style="width:120px;">177775000</td>
			<td style="width:347px;">Use heat to aid in dissolving</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Calcium chloride dihydrate</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">C79</td>
			<td style="width:347px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Canola oil</td>
			<td style="width:164px;">Local store</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Obtain from a local store</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Tween 20</td>
			<td style="width:164px;">Sigma-Aldrich</td>
			<td style="width:120px;">93773</td>
			<td style="width:347px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">70% (v/v) Isopropoanol</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">A416-4</td>
			<td style="width:347px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Porcine ears</td>
			<td style="width:164px;">Haine&#39;s Pork Shop</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Obtain from a local butcher</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Sodium Chloride</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">S271-3</td>
			<td style="width:347px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Human embryonic kidney 293 cells</td>
			<td style="width:164px;">ATCC</td>
			<td style="width:120px;">ATCC CRL-1573</td>
			<td style="width:347px;">Store in liquid nitrogen for long-term use</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">DMEM: 1X, high glucose, no pyruvate</td>
			<td style="width:164px;">Life Technologies</td>
			<td style="width:120px;">11965126</td>
			<td style="width:347px;">Refrigerate</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Fetal bovine serum</td>
			<td style="width:164px;">Life Technologies</td>
			<td style="width:120px;">10082-147</td>
			<td style="width:347px;">Refrigerate</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Penn Strep: 10,000 U/ml</td>
			<td style="width:164px;">Life Technologies</td>
			<td style="width:120px;">15140-122</td>
			<td style="width:347px;">Refrigerate</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Trypsin-EDTA: 0.5%, 10X</td>
			<td style="width:164px;">Life Technologies</td>
			<td style="width:120px;">15400-054</td>
			<td style="width:347px;">Refrigerate</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Methanol</td>
			<td style="width:164px;">VWR</td>
			<td style="width:120px;">AAA44571-K7</td>
			<td style="width:347px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Live/Dead Cell viability kit</td>
			<td style="width:164px;">Life Technologies</td>
			<td style="width:120px;">L3224</td>
			<td style="width:347px;">Light sensitive, keep frozen</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">XTT cell viability kit</td>
			<td style="width:164px;">Sigma Aldrich</td>
			<td style="width:120px;">TOX2-1KT</td>
			<td style="width:347px;">Light sensitive, keep frozen</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Clear DMEM: 1X, high glucose, no phenol</td>
			<td style="width:164px;">Life Technologies</td>
			<td style="width:120px;">21063-029</td>
			<td style="width:347px;">Refrigerate</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Dulbecco&#39;s PBS: 1X</td>
			<td style="width:164px;">Life Technologies</td>
			<td style="width:120px;">14190136</td>
			<td style="width:347px;">Refrigerate</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Sodium citrate</td>
			<td style="width:164px;">EMD</td>
			<td style="width:120px;">SX0445-1</td>
			<td style="width:347px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Positive displacement pipette</td>
			<td style="width:164px;">BrandTech Scientific, INC</td>
			<td style="width:120px;">2702904</td>
			<td style="width:347px;">Dispenses 100 - 500 &#181;L and comes with attachable tips</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">No 3. Stainless Steel scalpel handle</td>
			<td style="width:164px;">Sigma Aldrich</td>
			<td style="width:120px;">S2896</td>
			<td style="width:347px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Miltex sterile surgical blades</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">12-460-440</td>
			<td style="width:347px;">Size 10</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Power gem homogenizer</td>
			<td style="width:164px;">Fisher Scientific</td>
			<td style="width:120px;">08-451-660</td>
			<td style="width:347px;">Model # 125</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Porcelain mortar and pestle</td>
			<td style="width:164px;">Sigma Aldrich</td>
			<td style="width:120px;">Z247464</td>
			<td style="width:347px;">Holds 50 mL</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">FreeZone 1 L benchtop freeze dry system</td>
			<td style="width:164px;">Labconco</td>
			<td style="width:120px;">7740020</td>
			<td style="width:347px;">Freeze samples prior to use</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Oil sealed rotary vane pump</td>
			<td style="width:164px;">Edwards</td>
			<td style="width:120px;">A65301906</td>
			<td style="width:347px;">Model # RV5</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Incubating orbital shaker</td>
			<td style="width:164px;">VWR</td>
			<td style="width:120px;">12620-946</td>
			<td style="width:347px;">Model # 980153</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Benchtop refrigerated centrifuge</td>
			<td style="width:164px;">Forma Scientific, INC</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Model # 5682</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Heated ovens</td>
			<td style="width:164px;">VWR</td>
			<td></td>
			<td style="width:347px;">Model # 1235PC</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">2 N force gauge</td>
			<td style="width:164px;">Shimpo</td>
			<td style="width:120px;">FGV-0.5XY</td>
			<td style="width:347px;">Model # FGV-0.5XY</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">E-force test stand</td>
			<td style="width:164px;">Shimpo</td>
			<td style="width:120px;">FGS-200PV</td>
			<td style="width:347px;">Model # FGS-200PV</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Tissue culture swinging bucket centrifuge</td>
			<td style="width:164px;">Beckman Coulter</td>
			<td style="width:120px;">366830</td>
			<td style="width:347px;">Model #6S-6KR</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Tissue culture microcentrifuge</td>
			<td style="width:164px;">Eppendorf</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Model #5415C</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Hemacytometer set</td>
			<td style="width:164px;">Hausser Scientific</td>
			<td style="width:120px;">3720</td>
			<td style="width:347px;">Requires replacement cover glass slips</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Slide warmer</td>
			<td style="width:164px;">Lab Scientific</td>
			<td style="width:120px;">XH-2022</td>
			<td style="width:347px;">Model # XH-2002</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Portable heating lamp</td>
			<td style="width:164px;">Underwriters Laboratories</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Helps to maintain polymer temperature at 37&#176;C</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Inverted fluorescent microscope</td>
			<td style="width:164px;">Zeiss</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Model Axiovert 25 CFL</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:255px;">Heated water bath</td>
			<td style="width:164px;">VWR</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Model # 1235PC</td>
		</tr>
		<tr height="36">
			<td height="36" style="height:36px;width:255px;">Rocking platform</td>
			<td style="width:164px;">VWR</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Series 100</td>
		</tr>
		<tr height="36">
			<td height="36" style="height:36px;width:255px;">Multiskan FC microtiter plate reader</td>
			<td style="width:164px;">Thermo Scientific</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Type 357</td>
		</tr>
		<tr height="36">
			<td height="36" style="height:36px;width:255px;">Cell culture incubator</td>
			<td style="width:164px;">VWR</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Model # 2350T</td>
		</tr>
		<tr height="36">
			<td height="36" style="height:36px;width:255px;">Purifier class II biosafety cabinet</td>
			<td style="width:164px;">Labconco</td>
			<td style="width:120px;"></td>
			<td style="width:347px;">Delta Series</td>
		</tr>
	</tbody>
</table>

synthesis of thermogelling poly(n-isopropylacrylamide)-graft-chondroitin sulfate composites with alginate microparticles for tissue engineering

Enjekte edilebilir Biyo materyaller, bir sıvı olarak vücut içine ve yerinde katılaşmaya edilebilir implante edilebilir maddeler olarak tanımlanır. Bu gibi malzemeler, minimal invaziv ve kolay bir şekilde düzensiz şekilli kusurlar boşluk doldurucu katı oluşturan implante edilen klinik avantaj sağlar. Enjekte biyomalzemeler yaygın doku mühendisliği için iskeleler olarak incelenmiştir. Bununla birlikte, vücudun bazı yük taşıyan alanların onarımı için, örneğin vertebral disk gibi iskeleleri yapışkan özelliklere sahip olmalıdır. Bu kuvvetler, yeterli aktarımı sağlayan hareketi esnasında çıkış riskini en aza indirmek ve çevreleyen doku ile yakın temas sağlayacaktır. Burada, termal olarak hassas bir poli (N-izopropil akrilamid) oluşan bir iskele hazırlanmasını ve tanımlanmasını -graft-kondroitin sülfat (PNIPAAM-g-CS) ve aljinat mikro açıklar. PNIPAAm-g-CS kopolimeri aljinat içine oda sıcaklığında su içinde viskoz bir çözelti oluşturure parçacıkları yapışma geliştirmek için askıya alınır. 30 ° C civarında daha düşük kritik çözelti sıcaklığı (LCST&#39;nin), üzerinde, kopolimer mikro etrafında katı bir jel oluşturur. Biz dikkate PNIPAAm-g-CS geri dönüşümlü faz geçişi almaya standart biyomateryaller karakterizasyon prosedürleri adapte var. Sonuçlar% 5 olarak 50 ya da 75 mg / ml aljinat parçacıklarının ilave edilmesi, (a / h) PNIPAAm-g-CS çözeltiler, tek başına PNIPAAm-GCS çekme dayanımı (p &lt;0.05) dört katına göstermektedir. alginat mikro parçacıkların dahil edilmesi de önemli ölçüde doku defektlerinin içinde boşluk doldurucu jel korumak için yardımcı PNIPAAm-g-CS şişme kapasitesi (p &lt;0.05) arttırır. Son olarak, 2,3-bis-in vitro Toksikoloji deney kiti sonuçları (2-metoksi-4-nitro-5-sülfofenil) -2H-tetrazolyum-5-karboksanilid (XTT) ve canlı / ölü canlılığı deneyi göstermektedir yapışkan hayatta kalma ve kapsüllü İnsan Embriyonik Böbrek çoğalmasını destekleme yeteneğine sahip (HEK) 293 c5 gün boyunca arşın.

Bir termal duyarlı aşılanmış ko-polimer başarıyla sentezlenmiş ve biyoadheziv dayanıklılık için karakterize özellikleri şişme ve in vitro hücre proliferasyonu içinde oldu. Biz nedeniyle köklü mukozaya yapışan özellikleri aljinat araştırmak için seçti. ± 14.9 um 59,7 arasında bir ortalama çapa sahip aljinat mikropartiküller,% 5 ile harmanlandı (a / h), 25, 50 ve 75 mg / ml&#39;lik konsantrasyonlarda PNIPAAm-g-CS. Bu konsantrasyonlar, eşit ...

Watch this Scientific Journal Video about Synthesis of Thermogelling PolyN-isopropylacrylamide-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering at JoVE.com

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

poli (N-izopropil akrilamid) -graft-kondroitin sülfat oluşan enjekte edilebilir doku mühendisliği iskelesi (PNIPAAm-g-CS) içeren aljinat mikro hazırlandı. Özellikleri ve in vitro biyouyumluluk şişme yapışma mukavemeti, bu çalışmada incelenmiştir. Burada geliştirilen karakterizasyon teknikleri diğer thermogelling sistemleri için geçerli olabilir.

Doku Mühendisliği Aljinat mikropartiküllerin ile Thermogelling Poli (N-izopropil) -graft-kondroitin Sülfat Kompozitlerin Sentezi

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

synthesis-thermogelling-poly-n-isopropylacrylamide-graft-chondroitin

Research

JoVE Journal

Bioengineering

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

11.7K Görüntüleme.  Rowan University.  poli (N-izopropil akrilamid) -graft-kondroitin sülfat oluşan enjekte edilebilir doku mühendisliği iskelesi (PNIPAAm-g-CS) içeren aljinat mikro hazırlandı. Özellikleri ve in vitro biyouyumluluk şişme yapışma mukavemeti, bu çalışmada incelenmiştir. Burada geliştirilen karakterizasyon teknikleri diğer thermogelling sistemleri için geçerli olabilir. 

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

Fabrication of Biologically Derived Injectable Materials for Myocardial Tissue Engineering

This protocol provides methods for the preparation of an injectable extracellular matrix (ECM) gel for myocardial tissue engineering applications. Briefly, decellularized tissue is lyophilized, milled, enzymatically digested, and then brought to physiological pH. The lyophilization removes all water content from the tissue, resulting in dry ECM that can be ground into a fine powder with a small mill. After milling, the ECM powder is digested with pepsin to form an injectable matrix. After adjustment to pH 7.4, the liquid matrix material can be injected into the myocardium. Results of previous characterization assays have shown that matrix gels produced from decellularized pericardial and myocardial tissue retain native ECM components, including diverse proteins, peptides and glycosaminoglycans. Given the use of this material for tissue engineering, in vivo characterization is especially useful; here, a method for performing an intramural injection into the left ventricular (LV) free wall is presented as a means of analyzing the host response to the matrix gel in a small animal model. Access to the chest cavity is gained through the diaphragm and the injection is made slightly above the apex in the LV free wall. The biologically derived scaffold can be visualized by biotin-labeling before injection and then staining tissue sections with a horse radish peroxidase-conjugated neutravidin and visualizing via diaminobenzidine (DAB) staining. Analysis of the injection region can also be done with histological and immunohistochemical staining. In this way, the previously examined pericardial and myocardial matrix gels were shown to form fibrous, porous networks and promote vessel formation within the injection region.

Methods for preparing an injectable matrix gel from decellularized tissue and injecting it into rat myocardium in vivo are described.

Miyokard Doku Mühendisliği Biyolojik Türetilmiş Enjektabl Malzeme imalatı

This protocol provides methods for the preparation of an injectable extracellular matrix (ECM) gel for myocardial tissue engineering applications.  ...

Biyomühendislik

Elastomeric PGS Scaffolds in Arterial Tissue Engineering

Cardiovascular disease is one of the leading cause of mortality in the US and especially, coronary artery disease increases with an aging population and increasing obesity1. Currently, bypass surgery using autologous vessels, allografts, and synthetic grafts are known as a commonly used for arterial substitutes2. However, these grafts have limited applications when an inner diameter of arteries is less than 6 mm due to low availability, thrombotic complications, compliance mismatch, and late intimal hyperplasia3,4. To overcome these limitations, tissue engineering has been successfully applied as a promising alternative to develop small-diameter arterial constructs that are nonthrombogenic, robust, and compliant. Several previous studies have developed small-diameter arterial constructs with tri-lamellar structure, excellent mechanical properties and burst pressure comparable to native arteries5,6. While high tensile strength and burst pressure by increasing collagen production from a rigid material or cell sheet scaffold, these constructs still had low elastin production and compliance, which is a major problem to cause graft failure after implantation. Considering these issues, we hypothesized that an elastometric biomaterial combined with mechanical conditioning would provide elasticity and conduct mechanical signals more efficiently to vascular cells, which increase extracellular matrix production and support cellular orientation.
The objective of this report is to introduce a fabrication technique of porous tubular scaffolds and a dynamic mechanical conditioning for applying them to arterial tissue engineering. We used a biodegradable elastomer, poly (glycerol sebacate) (PGS)7 for fabricating porous tubular scaffolds from the salt fusion method. Adult primary baboon smooth muscle cells (SMCs) were seeded on the lumen of scaffolds, which cultured in our designed pulsatile flow bioreactor for 3 weeks. PGS scaffolds had consistent thickness and randomly distributed macro- and micro-pores. Mechanical conditioning from pulsatile flow bioreactor supported SMC orientation and enhanced ECM production in scaffolds. These results suggest that elastomeric scaffolds and mechanical conditioning of bioreactor culture may be a promising method for arterial tissue engineering.

Elastomeric PGS scaffolds with vascular smooth muscle cells cultured in a pulsatile flow bioreactor may lead to promising small-diameter arterial constructs with native ECM production in a relatively short culture period.

Elastomerik PGS Arter Doku Mühendisliği Yapı iskeleleri

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

Postproduction Processing of Electrospun Fibres for Tissue Engineering

Electrospinning is a commonly used and versatile method to produce scaffolds (often biodegradable) for 3D tissue engineering.1, 2, 3 Many tissues in vivo undergo biaxial distension to varying extents such as skin, bladder, pelvic floor and even the hard palate as children grow. In producing scaffolds for these purposes there is a need to develop scaffolds of appropriate biomechanical properties (whether achieved without or with cells) and which are sterile for clinical use. The focus of this paper is not how to establish basic electrospinning parameters (as there is extensive literature on electrospinning) but on how to modify spun scaffolds post production to make them fit for tissue engineering purposes - here thickness, mechanical properties and sterilisation (required for clinical use) are considered and we also describe how cells can be cultured on scaffolds and subjected to biaxial strain to condition them for specific applications.
Electrospinning tends to produce thin sheets; as the electrospinning collector becomes coated with insulating fibres it becomes a poor conductor such that fibres no longer deposit on it. Hence we describe approaches to produce thicker structures by heat or vapour annealing increasing the strength of scaffolds but not necessarily the elasticity. Sequential spinning of scaffolds of different polymers to achieve complex scaffolds is also described. Sterilisation methodologies can adversely affect strength and elasticity of scaffolds. We compare three methods for their effects on the biomechanical properties on electrospun scaffolds of poly lactic-co-glycolic acid (PLGA).
Imaging of cells on scaffolds and assessment of production of extracellular matrix (ECM) proteins by cells on scaffolds is described. Culturing cells on scaffolds in vitro can improve scaffold strength and elasticity but the tissue engineering literature shows that cells often fail to produce appropriate ECM when cultured under static conditions. There are few commercial systems available that allow one to culture cells on scaffolds under dynamic conditioning regimes - one example is the Bose Electroforce 3100 which can be used to exert a conditioning programme on cells in scaffolds held using mechanical grips within a media filled chamber.4 An approach to a budget cell culture bioreactor for controlled distortion in 2 dimensions is described. We show that cells can be induced to produce elastin under these conditions. Finally assessment of the biomechanical properties of processed scaffolds cultured with or without cells is described.

Electrospun scaffolds can be processed post production for tissue engineering applications. Here we describe methods for spinning complex scaffolds (by consecutive spinning), for making thicker scaffolds (by multi-layering using heat or vapour annealing), for achieving sterility (aseptic production or sterilisation post production) and for achieving appropriate biomechanical properties.

Doku Mühendisliği için elektrospinning Liflerin Postprodüksiyon İşleme

Electrospinning is a commonly used and versatile method to produce  scaffolds (often biodegradable) for 3D tissue engineering.1, 2, 3 Many tissues in vivo ...

Capillary Force Lithography for Cardiac Tissue Engineering

Cardiovascular disease remains the leading cause of death worldwide1. Cardiac tissue engineering holds much promise to deliver groundbreaking medical discoveries with the aims of developing functional tissues for cardiac regeneration as well as in vitro screening assays. However, the ability to create high-fidelity models of heart tissue has proven difficult. The heart&#8217;s extracellular matrix (ECM) is a complex structure consisting of both biochemical and biomechanical signals ranging from the micro- to the nanometer scale2. Local mechanical loading conditions and cell-ECM interactions have recently been recognized as vital components in cardiac tissue engineering3-5.
A large portion of the cardiac ECM is composed of aligned collagen fibers with nano-scale diameters that significantly influences tissue architecture and electromechanical coupling2. Unfortunately, few methods have been able to mimic the organization of ECM fibers down to the nanometer scale. Recent advancements in nanofabrication techniques, however, have enabled the design and fabrication of scalable scaffolds that mimic the in vivo structural and substrate stiffness cues of the ECM in the heart6-9.
Here we present the development of two reproducible, cost-effective, and scalable nanopatterning processes for the functional alignment of cardiac cells using the biocompatible polymer poly(lactide-co-glycolide) (PLGA)8 and a polyurethane (PU) based polymer. These anisotropically nanofabricated substrata (ANFS) mimic the underlying ECM of well-organized, aligned tissues and can be used to investigate the role of nanotopography on cell morphology and function10-14.
Using a nanopatterned (NP) silicon master as a template, a polyurethane acrylate (PUA) mold is fabricated. This PUA mold is then used to pattern the PU or PLGA hydrogel via UV-assisted or solvent-mediated capillary force lithography (CFL), respectively15,16. Briefly, PU or PLGA pre-polymer is drop dispensed onto a glass coverslip and the PUA mold is placed on top. For UV-assisted CFL, the PU is then exposed to UV radiation (&#955; = 250-400 nm) for curing. For solvent-mediated CFL, the PLGA is embossed using heat (120 &#176;C) and pressure (100 kPa). After curing, the PUA mold is peeled off, leaving behind an ANFS for cell culture. Primary cells, such as neonatal rat ventricular myocytes, as well as human pluripotent stem cell-derived cardiomyocytes, can be maintained on the ANFS2.

In this protocol, we demonstrate the fabrication of biomimetic cardiac cell culture substrata made from two distinct polymeric materials using capillary force lithography. The described methods provide a scalable, cost-effective technique to engineer the structure and function of macroscopic cardiac tissues for in vitro and in vivo applications.

Kardiyak Doku Mühendisliği kılcal Kuvvetleri Litografi

Cardiovascular disease remains the leading cause of death worldwide1. Cardiac tissue engineering holds much promise to deliver groundbreaking medical ...

Tissue Engineering of Tumor Stromal Microenvironment with Application to Cancer Cell Invasion

3D organotypic cultures of epithelial cells on a matrix embedded with mesenchymal cells are widely used to study epithelial cell differentiation and invasion. Rat tail type I collagen and/or matrix derived from Engelbreth-Holm-Swarm mouse sarcoma cells have been traditionally employed as the substrates to model the matrix or stromal microenvironment into which mesenchymal cells (usually fibroblasts) are populated. Although experiments using such matrices are very informative, it can be argued that due to an overriding presence of a single protein (such as in type I Collagen) or a high content of basement membrane components and growth factors (such as in matrix derived from mouse sarcoma cells), these substrates do not best reflect the contribution to matrix composition made by the stromal cells themselves. To study native matrices produced by primary dermal fibroblasts isolated from patients with a tumor prone, genetic blistering disorder (recessive dystrophic epidermolysis bullosa), we have adapted an existing native matrix protocol to study tumor cell invasion. Fibroblasts are induced to produce their own matrix over a prolonged period in culture. This native matrix is then detached from the culture dish and epithelial cells are seeded onto it before the entire coculture is raised to the air-liquid interface. Cellular differentiation and/or invasion can then be assessed over time. This technique provides the ability to assess epithelial-mesenchymal cell interactions in a 3D setting without the need for a synthetic or foreign matrix with the only disadvantage being the prolonged period of time required to produce the native matrix. Here we describe the application of this technique to assess the ability of a single molecule expressed by fibroblasts, type VII collagen, to inhibit tumor cell invasion.

Tissue engineered fibroblast-derived native matrix is an emerging tool to generate a stromal substrate which supports epithelial cell proliferation and differentiation. Here a protocol applying this methodology to assess the impact of different stromal cell types on tumor cell biology is presented.

Kanser Hücre Invasion Uygulama ile Tümör Stromal mikroçevresinin Doku Mühendisliği

3D organotypic cultures of epithelial cells on a matrix embedded with mesenchymal cells are widely used to study epithelial cell differentiation and ...

Engineering 3D Cellularized Collagen Gels for Vascular Tissue Regeneration

Synthetic materials are known to initiate clinical complications such as inflammation, stenosis, and infections when implanted as vascular substitutes. Collagen has been extensively used for a wide range of biomedical applications and is considered a valid alternative to synthetic materials due to its inherent biocompatibility (i.e., low antigenicity, inflammation, and cytotoxic responses). However, the limited mechanical properties and the related low hand-ability of collagen gels have hampered their use as scaffold materials for vascular tissue engineering. Therefore, the rationale behind this work was first to engineer cellularized collagen gels into a tubular-shaped geometry and second to enhance smooth muscle cells driven reorganization of collagen matrix to obtain tissues stiff enough to be handled.
The strategy described here is based on the direct assembling of collagen and smooth muscle cells (construct) in a 3D cylindrical geometry with the use of a molding technique. This process requires a maturation period, during which the constructs are cultured in a bioreactor under static conditions (without applied external dynamic mechanical constraints) for 1 or 2 weeks. The &#8220;static bioreactor&#8221; provides a monitored and controlled sterile environment (pH, temperature, gas exchange, nutrient supply and waste removal) to the constructs. During culture period, thickness measurements were performed to evaluate the cells-driven remodeling of the collagen matrix, and glucose consumption and lactate production rates were measured to monitor the cells metabolic activity. Finally, mechanical and viscoelastic properties were assessed for the resulting tubular constructs. To this end, specific protocols and a focused know-how (manipulation, gripping, working in hydrated environment, and so on) were developed to characterize the engineered tissues.

In this work, we present a technique for the rapid fabrication of living vascular tissues by direct culturing of collagen, smooth muscle cells and endothelial cells. In addition, a new protocol for the mechanical characterization of engineered vascular tissues is described.

Vasküler Doku Rejenerasyon için Mühendislik 3D cellularized Kollajen jeller

Synthetic materials are known to initiate clinical complications such as inflammation, stenosis, and infections when implanted as vascular substitutes. ...

Synthesis of Keratin-based Nanofiber for Biomedical Engineering

Electrospinning, due to its versatility and potential for applications in various fields, is being frequently used to fabricate nanofibers. Production of these porous nanofibers is of great interest due to their unique physiochemical properties. Here we elaborate on the fabrication of keratin containing poly (&#949;-caprolactone) (PCL) nanofibers (i.e., PCL/keratin composite fiber). Water soluble keratin was first extracted from human hair and mixed with PCL in different ratios. The blended solution of PCL/keratin was transformed into nanofibrous membranes using a laboratory designed electrospinning set up. Fiber morphology and mechanical properties of the obtained nanofiber were observed and measured using scanning electron microscopy and tensile tester. Furthermore, degradability and chemical properties of the nanofiber were studied by FTIR. SEM images showed uniform surface morphology for PCL/keratin fibers of different compositions. These PCL/keratin fibers also showed excellent mechanical properties such as Young&#39;s modulus and failure point. Fibroblast cells were able to attach and proliferate thus proving good cell viability. Based on the characteristics discussed above, we can strongly argue that the blended nanofibers of natural and synthetic polymers can represent an excellent development of composite materials that can be used for different biomedical applications.

Electrospun nanofibers have a high surface area to weight ratio, excellent mechanical integrity, and support cell growth and proliferation. These nanofibers have a wide range of biomedical applications. Here we fabricate keratin/ PCL nanofibers, using the electrospinning technique, and characterize the fibers for possible applications in tissue engineering.

Biyomedikal Mühendisliği için keratin bazlı nanofiber sentezi

Electrospinning, due to its versatility and potential for applications in various fields, is being frequently used to fabricate nanofibers. Production of ...

Preparation of Thermoresponsive Nanostructured Surfaces for Tissue Engineering

Thermoresponsive poly(N-isopropylacrylamide) (PIPAAm)-immobilized surfaces for controlling cell adhesion and detachment were fabricated by the Langmuir-Schaefer method. Amphiphilic block copolymers composed of polystyrene and PIPAAm (St-IPAAms) were synthesized by reversible addition-fragmentation chain transfer (RAFT) radical polymerization. A chloroform solution of St-IPAAm molecules was gently dropped into a Langmuir-trough apparatus, and both barriers of the apparatus were moved horizontally to compress the film to regulate its density. Then, the St-IPAAm Langmuir film was horizontally transferred onto a hydrophobically modified glass substrate by a surface-fixed device. Atomic force microscopy images clearly revealed nanoscale sea-island structures on the surface. The strength, rate, and quality of cell adhesion and detachment on the prepared surface were modulated by changes in temperature across the lower critical solution temperature range of PIPAAm molecules. In addition, a two-dimensional cell structure (cell sheet) was successfully recovered on the optimized surfaces. These unique PIPAAm surfaces may be useful for controlling the strength of cell adhesion and detachment.

Nanoscaled sea-island surfaces composed of thermoresponsive block copolymers were fabricated by the Langmuir-Schaefer method for controlling spontaneous cell adhesion and detachment. Both the preparation of the surface and the adhesion and detachment of cells on the surface were visualized.

Doku Mühendisliği Thermoresponsive Nanostructured Yüzeylerin Hazırlanması

Thermoresponsive poly(N-isopropylacrylamide) (PIPAAm)-immobilized surfaces for controlling cell adhesion and detachment were fabricated by the ...

Tissue Engineering by Intrinsic Vascularization in an In Vivo Tissue Engineering Chamber

In reconstructive surgery, there is a clinical need for an alternative to the current methods of autologous reconstruction which are complex, costly and trade one defect for another. Tissue engineering holds the promise to address this increasing demand. However, most tissue engineering strategies fail to generate stable and functional tissue substitutes because of poor vascularization. This paper focuses on an in vivo tissue engineering chamber model of intrinsic vascularization where a perfused artery and a vein either as an arteriovenous loop or a flow-through pedicle configuration is directed inside a protected hollow chamber. In this chamber-based system angiogenic sprouting occurs from the arteriovenous vessels and this system attracts ischemic and inflammatory driven endogenous cell migration which gradually fills the chamber space with fibro-vascular tissue. Exogenous cell/matrix implantation at the time of chamber construction enhances cell survival and determines specificity of the engineered tissues which develop. Our studies have shown that this chamber model can successfully generate different tissues such as fat, cardiac muscle, liver and others. However, modifications and refinements are required to ensure target tissue formation is consistent and reproducible. This article describes a standardized protocol for the fabrication of two different vascularized tissue engineering chamber models in vivo.

Tissue Engineering by Intrinsic Vascularization in an In Vivo Tissue Engineering Chamber

This is a guideline for constructing in vivo vascularized tissue using a microsurgical arteriovenous loop or a flow-through pedicle configuration inside a tissue engineering chamber. The vascularized tissues generated can be employed for organ regeneration and replacement of tissue defects, as well as for drug testing and disease modeling.

Bir ıntrinsic Vaskülarizasyon tarafından Doku Mühendisliği<em&gt; İn Vivo</em&gt; Doku Mühendisliği Odası

In reconstructive surgery, there is a clinical need for an alternative to the current methods of autologous reconstruction which are complex, costly and ...

Synthesis of Hydrogels with Antifouling Properties As Membranes for Water Purification

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and thus achieving stable water permeability through membranes over time. Here, we report a facile method to prepare hydrogels based on zwitterions for membrane applications. Freestanding films can be prepared from sulfobetaine methacrylate (SBMA) with a crosslinker of poly(ethylene glycol) diacrylate (PEGDA) via photopolymerization. The hydrogels can also be prepared by impregnation into hydrophobic porous supports to enhance the mechanical strength. These films can be characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine the degree of conversion of the (meth)acrylate groups, using goniometers for hydrophilicity and differential scanning calorimetry (DSC) for polymer chain dynamics. We also report protocols to determine the water permeability in dead-end filtration systems and the effect of foulants (bovine serum albumin, BSA) on membrane performance.

This paper reports practical methods to prepare hydrogels in freestanding films and impregnated membranes and to characterize their physical properties, including water transport properties.

Su Arıtma Membranlar olarak Zehirli Özelliklere Sahip Hidrojeller Sentezi

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and ...