Name: wet-spinning-based molding process of gelatin for tissue regeneration
Uploaded: 2019-03-07T14:15:00
Description: Watch this Scientific Journal Video about Wet-spinning-based Molding Process of Gelatin for Tissue Regeneration at JoVE.com

Este estudo foi suportado pelo Ministério da defesa nacional (MAB-105-070; MAB-106-077; MAB-107-032; Mab-107-065), o Ministério da ciência e tecnologia (a maioria dos 107-2320-B016-016), Tri-Service General Hospital, o National Defense centro médico, Taiwan (TSGH-C106-046; TSGH-C106-115; TSGH-C107-041) e Hospital Geral de Cheng-Hsin e cooperação centro de médico de defesa nacional (CH-NDMC-107-8).

Os tecidos gordos foram obtidos em cirurgias ortopédicas como certificada pelo institucional Review Board do Tri-serviço geral Hospital, Taipei, Taiwan, R.O.C. procedimentos envolvendo assuntos animais foram aprovados pelo Comitê de cuidado Animal nacional Centro médico de defesa, Taiwan (R.O.C).
1. Umedeça girando o processo
<ol><li>
Preparação da solução
	<ol>
<li>Dissolva 5 g de gelatina em pó em 100 mL de água bidestilada para obter a concentração da soluç?...

<ol>
	<li>Bagnall, A. M., Jones, L., Duffy, S., Riemsima, R. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+fixation+surgery+for+acute+traumatic+spinal+cord+injury.">Spinal fixation surgery for acute traumatic spinal cord injury.</a> Cochrane Database of Systematic Reviews. 1, 004725 (2008).</li><li>Fehlings, M. G., Perrin, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+and+timing+of+early+decompression+for+cervical+spinal+cord+injury:+update+with+a+review+of+recent+clinical+evidence.">The role and timing of early decompression for cervical spinal cord injury: update with a review of recent clinical evidence.</a> Injury. 36, 13-26 (2005).</li><li>Yang, L., Jones, N. R., Stoodley, M. A., Blumbergs, P. C., Brown, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Excitotoxic+model+of+post-traumatic+syringomyelia+in+the+rat.">Excitotoxic model of post-traumatic syringomyelia in the rat.</a> Spine. 26, 1842-1849 (2001).</li><li>Rolls, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two+faces+of+chondroitin+sulfate+proteoglycan+in+spinal+cord+repair:+a+role+in+microglia/macrophage+activation.">Two faces of chondroitin sulfate proteoglycan in spinal cord repair: a role in microglia/macrophage activation.</a> PLoS Medicine. 5, 1262-1277 (2008).</li><li>Properzi, F., Asher, R. A., Fawcett, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chondroitin+sulphate+proteoglycans+in+the+central+nervous+system:+changes+and+synthesis+after+injury.">Chondroitin sulphate proteoglycans in the central nervous system: changes and synthesis after injury.</a> Biochemical Society Transactions. 31, 335-336 (2003).</li><li>Fawcett, J. W., Asher, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+glial+scar+and+central+nervous+system+repair.">The glial scar and central nervous system repair.</a> Brain Research Bulletin. 49, 377-391 (1999).</li><li>Yang, Z., Mo, L., Duan, H., Li, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+chitosan/collagen+substrates+on+the+behavior+of+rat+neural+stem+cells.">Effects of chitosan/collagen substrates on the behavior of rat neural stem cells.</a> Science China Life Sciences. 53, 215-222 (2010).</li><li>Chawla, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Fibrous Materials. , (1998).</li><li>Pickering, K. L., Aruan Efendy, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+recent+developments+in+natural+fibre+composites+and+their+mechanical+performance.">A review of recent developments in natural fibre composites and their mechanical performance.</a> Composites Part A-Applied Science and Manufacturing. 83, 98-112 (2016).</li><li>Lundgren, H. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthetic+fibers+made+from+proteins.">Synthetic fibers made from proteins.</a> Advances in Protein Chemistry. 5, 305-351 (1954).</li><li>Radishevskii, M. B., Serkov, A. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coagulation+mechanism+in+wet+spinning+of+fibres.">Coagulation mechanism in wet spinning of fibres.</a> Fibre Chemistry. 37, 266-271 (2005).</li><li>Yannas, I. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collagen+and+gelatin+in+the+solid+state.">Collagen and gelatin in the solid state.</a> Journal of Macromolecular Science Part C Polymer Reviews. 7, 49-106 (1972).</li><li>Baer, E., Cassidy, J. J., Hiltner, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hierarchical+structure+of+collagen+composite+Systems:+lessons+from+biology.">Hierarchical structure of collagen composite Systems: lessons from biology.</a> Pure and Applied Chemistry. 6, 961-973 (2009).</li><li>Harrington, W. F., Von Hippel, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+structure+of+collagen+and+gelatin.">The structure of collagen and gelatin.</a> Advances in Protein Chemistry. 16, 1-138 (1961).</li><li>Veis, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Macromolecular Chemistry of Gelatin. , (1994).</li><li>Freyman, T. M., Yannas, I. V., Gibson, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+materials+as+porous+scaffolds+for+tissue+engineering.">Cellular materials as porous scaffolds for tissue engineering.</a> Progress in Materials Science. 46, 273-282 (2001).</li><li>Michalczyk, K., Ziman, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nestin+structure+and+predicted+function+in+cellular+cytoskeletal+organization.">Nestin structure and predicted function in cellular cytoskeletal organization.</a> Histology and Histopathology. 20, 665-671 (2005).</li></ol>

Apresentamos o desenvolvimento de biomateriais baseados em gelatina usando um simples molhado girando a técnica que pode ser aplicada no estudo de polímeros naturais para a regeneração de tecidos. Este trabalho demonstrou a possibilidade de fabricação de gelatina como fonte de proteína excelente, sem adição de outras fontes, com o objetivo de otimizar as propriedades da gelatina em si. O desenvolvimento de biomateriais baseados em gelatina foi inteiramente realizado em temperatura ambiente (22-26 ° C). Uma prep...

O mais recente desenvolvimento na regeneração de tecidos envolve a aplicação de engenharia de tecidos, o que representa um desafio para a melhoria de novas estratégias terapêuticas em tratamentos médicos. Por exemplo, o limitado potencial de regeneração do sistema nervoso, seguir lesão ou doença, coloca um problema de saúde significativo em todo o mundo. Devido à complexidade dos processos fisiopatológicos associados com o sistema nervoso, o uso de auto-enxerto tradicional ou a execução de cirurgia de estabilização tem sido mostrada para oferecer benefícios em termos de resultados funcionais, mas não há nenhuma evidência forte para os efeitos de fixação da coluna vertebral, cirurgia1,2. O tecido na área danificada é perdido e substituído com astrócitos hypertrophically induzido3, eventualmente formando uma densa cicatriz glial4,5. Esta matriz age como uma barreira que bloqueia a recuperação do nervo função6,7 e é, assim, dificulta grandemente regeneração. Portanto, espera-se um material de abertura de enchimento adequado para evitar a perda de tecido e reduzir a formação de cicatriz-associado do tecido conjuntivo, mantendo a integridade da área danificada, bem como fornecendo a substituição direta de células neurais e circuitos para promover a regeneração do axônio.
Biomateriais poliméricos tem sido preferidos como andaimes para a terapia de regeneração de tecido, baseado na regulamentação da progressão de comportamento e o tecido celular ou axônio através de suporte natural da matriz extracelular (ECM). O formato da fibra é comumente considerado como um bloco de construção para vários materiais, devido à sua estrutura unidimensional8. As fibras geralmente podem ser obtidas por extrusão de derretimento ou molhado girando o método; no entanto, o grande tamanho e custo do equipamento e a dificuldade para realizar esses métodos são desafiadores. Além disso, a maioria dos trabalhos relacionados com fibras de polímero tem sido focada em materiais sintéticos ou compostos. Polímeros naturais como fonte de biomaterial oferecem melhor biocompatibilidade Propriedades, para o corpo humano. No entanto, para obter o alinhamento das fibras de polímero natural é relativamente mais difícil do que de polímero sintético fontes9. Portanto, a conversão de um polímero natural, como uma rica fonte de proteína em fibras biomaterial é uma importante estratégia — não somente as fibras do biomaterial podem ser diretamente isolado da matéria-prima, evitando assim uma transformação desnecessária de monômeros, mas o fibras de proteínas também têm uma boa aparência e características favoráveis10.
A este respeito, nós descrevemos um método de baixo custo de processamento para a fabricação de fibras de polímero natural através do conceito básico de fiação úmida, que pode ser implementada na escala de laboratório para a engenharia de tecidos. Fiação úmida é executada pela extrusão e coagulação de uma solução de polímero em um nonsolvent de polímero apropriado. Uma solução adequada, viscous dopada em meio de coagulação faz com que as moléculas de polímero dissolver. Durante a transição de fase, os filamentos então perdem sua solubilidade e são precipitados sob a forma de um polímero sólido fase11. Referindo-se a este conceito, então ampliamos o desenvolvimento de gelatina para a forma de tubo por um processo de moldagem, que é considerado adequado para a aplicação de regeneração do tecido. Além disso, intrinsecamente, podemos também desenvolver qualquer forma de material de fibras de gelatina (por exemplo, canalização de gelatina enrolado de várias fibras de gelatina), para outro desejado aplicações.
Gelatina, um polímero natural e biodegradável, é formada por colágeno hidrolisado e desnaturado, incluindo qualquer estado helicoidal semicrystalline, amorfo ou triplo de colágeno12. É sabido que o colágeno é a proteína estrutural essencial em todos os tecidos conjuntivos de vertebrados e invertebrados13,14, que é semelhante à estrutura da proteína do ECM principal que induz o crescimento do nervo e, simultaneamente, substitui uma grande quantidade de glicosaminoglicano secretada durante lesões na medula espinhal. Portanto, o uso da gelatina como uma fonte seria uma ótima escolha para qualquer veículo a médica. Além de ser uma fonte de baixo custo, a gelatina também é biodegradável e cytocompatible e clinicamente provado ser um temporário defeito de enchimento15. Desenvolvido em forma de tubo,, testes in vitro e in vivo, descritos aqui demonstram que a gelatina tem um excelente biocompatibilidade e adequação do tecido futura aplicações de engenharia. Cultivadas com células-tronco adiposas humanas, tubos de gelatina melhoram a diferenciação de célula em células progenitoras neurais usando positivo nestin coloração como um marcador de células nervosas. Além disso, gelatina como enchimento material de lacuna, como produzido pelo método estabelecido neste estudo, é esperada para ser seguro e gerenciável e beneficiar muito engenheiros de tecido que estão actualmente a desenvolver polímeros naturais correlativos ao reforço de tecido estratégias de regeneração.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td colspan="4">Solution preparation:</td>
		</tr>
		<tr>
			<td>Gelatin type B (porcine)</td>
			<td>Ferak</td>
			<td>Art. -Nr. 10733</td>
			<td>500 g vial</td>
		</tr>
		<tr>
			<td>Wet spinning process:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Peristaltic pump</td>
			<td>Gilson</td>
			<td>Model M312</td>
			<td>Minipuls*3</td>
		</tr>
		<tr>
			<td>Plastic tube connector</td>
			<td>World Precision Instruments</td>
			<td>14011</td>
			<td>1 box</td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>Sterican</td>
			<td>5A06258541</td>
			<td>26Gx1/2&#34;(0.45 x 12mm)</td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Ferak</td>
			<td>Art. -Nr. 00010</td>
			<td>2.5 L vial</td>
		</tr>
		<tr>
			<td>Polycaprolactone CAPA 6500</td>
			<td>Perstorp</td>
			<td>24980-41-4</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Dichloromethane&#160;</td>
			<td>Scharlau</td>
			<td>CL03421000</td>
			<td>1 L vial</td>
		</tr>
		<tr>
			<td>Glass Pasteur pipette</td>
			<td>Fisher Scientific</td>
			<td>13-678-20A</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Hemostat</td>
			<td>Shinetec instruments</td>
			<td>ST-B021</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Peripheral venous catheter (Introcan Certo)</td>
			<td>B. Braun</td>
			<td>1B03258241</td>
			<td>24Gx3/4&#34;(0.7 x 19mm)</td>
		</tr>
		<tr>
			<td colspan="4">Morphology of the gelatin tube:</td>
		</tr>
		<tr>
			<td>Ion sputter coater machine&#160;</td>
			<td>Hitachi</td>
			<td>e1010</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Scanning electron microscopy</td>
			<td>Hitachi</td>
			<td>S-3000N</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Cultivation of cells on the gelatin tube:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Gibco</td>
			<td>488625</td>
			<td>100 mL vial</td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>Gibco</td>
			<td>923119</td>
			<td>500 mL vial</td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s modified Eagle&#39;s medium&#160;</td>
			<td>Gibco</td>
			<td>31600-034</td>
			<td>Powder</td>
		</tr>
		<tr>
			<td>Keratinocyte-SFM medium</td>
			<td>Gibco</td>
			<td>10744-019</td>
			<td>500 mL vial</td>
		</tr>
		<tr>
			<td>T25 culture flask</td>
			<td>TPP</td>
			<td>90025</td>
			<td>VENT type</td>
		</tr>
		<tr>
			<td>6-well plate</td>
			<td>Falcon</td>
			<td>1209938</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Immunocytochemistry:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Phospate-buffered saline</td>
			<td>Gibco</td>
			<td>654471</td>
			<td>500 mL vial</td>
		</tr>
		<tr>
			<td>Acetic acid glacial</td>
			<td>Ferak</td>
			<td>Art. -Nr. 00697</td>
			<td>500 mL vial</td>
		</tr>
		<tr>
			<td>NP-40 surfactant (Tergitol solution)</td>
			<td>Sigma</td>
			<td>056K0151</td>
			<td>500 mL vial</td>
		</tr>
		<tr>
			<td>Normal goat serum</td>
			<td>Vector Laboratories</td>
			<td>S-1000-20</td>
			<td>20 mL vial, concentrate</td>
		</tr>
		<tr>
			<td>Nestin (primary antibody)</td>
			<td>Santa Cruz Biotechnology</td>
			<td>SC-23927</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Donkey anti-mouse-fluorescein isothiocyanate (secondary antibody)</td>
			<td>Santa Cruz Biotechnology</td>
			<td>SC-2099</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Hoechst 33342</td>
			<td>Anaspec</td>
			<td>AS-83218</td>
			<td>5 mL vial</td>
		</tr>
		<tr>
			<td>In vivo biocompatibility test:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tiletamine+zolazepam&#160;</td>
			<td>Virbac</td>
			<td>BC91</td>
			<td>5 mL vial</td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>Bayer korea</td>
			<td>KR03227</td>
			<td>10 mL vial</td>
		</tr>
		<tr>
			<td>Ketoprofen</td>
			<td>Astar</td>
			<td>1406232</td>
			<td>2 mL vial</td>
		</tr>
		<tr>
			<td>Povidone-iodine solution</td>
			<td>Everstar</td>
			<td>HA161202</td>
			<td>4 L barrel</td>
		</tr>
		<tr>
			<td>Cefazolin</td>
			<td>China Chemical &#38; Pharmaceutical</td>
			<td>18P909</td>
			<td>1 g vial</td>
		</tr>
		<tr>
			<td>Scalpel blade</td>
			<td>Shinetec instruments</td>
			<td>ST-B021</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Surgical scissor</td>
			<td>Shinetec instruments</td>
			<td>ST-B021</td>
			<td>-</td>
		</tr>
	</tbody>
</table>

wet-spinning-based molding process of gelatin for tissue regeneration

Este artigo apresenta um método de baixo custo para fabricar gelatina, como um polímero natural, em fibras monofilamento ou outras formas adequadas. Através da fiação método molhado, fibras de gelatina são fabricadas por extrusão suave em um meio adequado de coagulação. Para aumentar a superfície funcional destas fibras de gelatina e sua capacidade de imitar as características dos tecidos, a gelatina pode ser moldada em forma de tubo referindo-se a este conceito. Examinado por testes in vitro e in vivo, os tubos de gelatina demonstram um grande potencial para aplicação em engenharia de tecidos. Atuando como um material de enchimento adequado lacuna, gelatina de tubos podem ser usados para substituir o tecido na área danificada (por exemplo, no sistema nervoso ou cardiovascular), bem como a promover a revitalização, fornecendo uma substituição direta de células-tronco e circuitos neurais. Este protocolo fornece um procedimento detalhado para a criação de um biomaterial, baseado em um polímero natural, e sua implementação deverá beneficiar muito o desenvolvimento de polímeros naturais correlativos, que ajudam a perceber as estratégias de regeneração do tecido.

Neste estudo, temos desenvolvido com sucesso a gelatina em fibras(Figura 2)e tubos (Figura 2B, C), através do conceito de fiação úmida user-friendly. Estes materiais à base de gelatina podem ser utilizados como qualquer ferramenta médica, dependendo de suas formas. Considerando que a superfície funcional e quadro de tais materiais são mais apropriados para a regeneração dos tecidos, exa...

Watch this Scientific Journal Video about Wet-spinning-based Molding Process of Gelatin for Tissue Regeneration at JoVE.com

Wet-spinning-based Molding Process of Gelatin for Tissue Regeneration

Desenvolvemos e descrever um protocolo baseado no conceito de fiação úmida, para a construção de biomateriais baseados em gelatina, usada para a aplicação da engenharia de tecidos.

Processo de moldagem baseados em molhado-fiação de gelatina para regeneração de tecidos

This article presents an inexpensive method to fabricate gelatin, as a natural polymer, into monofilament fibers or other appropriate forms. Through the ...

Este protocolo melhora um conceito básico de fiação úmida para desenvolver um material a partir de uma única tira de fibra em várias tiras que podem ser usadas para qualquer aplicação médica preferida. Esta técnica é simples, barata, e não requer a adição de polímeros sintéticos para personalização dos polímeros naturais em um recurso de proteína para materiais de interesse. Esta técnica pode ser estendida ao desenvolvimento de biomateriais para matar a terapia fria, como tratamento do sistema nervoso central ou periférico, substituição de vasos sanguíneos ou reconstrução direta do trato urinário.Este método destina-se à aplicação médica, inclusive como estratégia para neuralização tecidual ou medicina regenerativa. Esta técnica pode ser facilmente implementada por iniciantes. Observe que, após várias repetições de moldagem, a qualidade da solução deve ser sempre verificada para manter uma formação ideal.Para formar o tubo giratório molhado, primeiro submerse um medidor de 24 por três quartos de polegada cateter venoso periférico em solução de gelatina recém-preparada por três segundos, seguido de imersão em solução de acetona recém-preparada por um minuto. Repita esses passos 20 vezes. Após a última imersão de acetona, deixe o tubo moldado secar por cinco minutos à temperatura ambiente, e use um hemostat para transferir cuidadosamente o tubo de gelatina do cateter para uma pipeta Pasteur de vidro com solução de diclorometano de policaprolactona de 2,5% para uma incubação durante a noite sob a temperatura ambiente.Na manhã seguinte, esterilize a gelatina por duas horas sob luz ultravioleta antes de submergir brevemente o tubo em 75% de etanol. Em seguida, lave o tubo duas vezes com o meio de células-tronco para remover o etanol residual. Para cultivar o tubo de gelatina com a cultura celular, substitua a extremidade supinada das células-tronco adiposas humanas de um frasco de cultura com um mililitro de 0,25% Trypsin-EDTA para uma incubação de 3,5 minutos a 37 graus Celsius e 5% de dióxido de carbono.Quando as células se separarem, prendam a reação com um mililitro de soro bovino fetal e transfiram a suspensão celular para um tubo de microcentrifuge. Colete as células por centrifugação e resuspense a pelota em um mililitro de meio de células-tronco. Em seguida, coloque o tubo de gelatina em um poço de uma placa de seis poços contendo três mililitros de meio de células-tronco.Depois de contar as células, a semente quatro vezes 10 a 4 das células-tronco adiposas humanas no tubo para uma incubação de duas semanas na incubadora de cultura celular. Depois de confirmar o nível apropriado de sedação por falta de resposta ao beliscão do dedo do pé em uma fêmea de oito semanas de idade, raspe o cabelo da área trapézio e esterilize a pele exposta com solução povidone-iodo. Cubra o rato com cortinas cirúrgicas estéreis para reduzir a contaminação bacteriana do local cirúrgico e use uma tesoura cirúrgica para fazer uma incisão de pele rasa de dois centímetros de comprimento.Coloque o tubo de gelatina diretamente na camada entre a fáscia e o músculo e use uma sutura de nylon para fechar a ferida. Em seguida, esterilize a incisão com solução povidone-iodo. Induzir o rato através de uma injeção intramuscular de cetoprofeno e cefazolina e manter o animal sob condições assépticas por sete dias.Este conceito de fiação molhada amigável pode ser usado para desenvolver gelatina em fibras e tubos. Observações morfológicas do tubo de gelatina por meio da microscopia eletrônica de varredura revelam uma superfície não muito lisa com um diâmetro interno superior a 200 micrômetros e uma espessura de aproximadamente 20 micrômetros. A coloração de um tubo de gelatina de cultura de células-tronco adiposas humanas para a expressão do marcador de células neurais demonstra uma coloração positiva para o marcador, juntamente com múltiplos núcleos detectados sugerindo que as células podem penetrar e aderir ao tubo de gelatina e se diferenciar em células progenitoras neurais.A implantação do tubo de gelatina na camada de fáscia confirma sua segurança e biocompatibilidade, pois não há indicação de vermelhidão, inchaço ou outros sintomas de inflamação no tecido local e o tubo é cercado por tecido conjuntivo bem desenvolvido. Ao tentar este procedimento de dois pontos um, garantir a imersão do molde no tempo específico de revestimento em cada solução é muito importante para construir uma forma precisa de tubo. Após este procedimento, nossos experimentos utilizam modelo animal de doença humana para investigar com precisão o resultado dos biomateriais para a estratégia de regeneração tecidual.Após seu desenvolvimento, essa técnica abriu caminho para os pesquisadores no desenvolvimento de polímeros de natureza correlativa simples em qualquer tipo de material para uma aplicação médica decidida. Em condição normal de uso, a solução de policaprolactona dicloroometano é considerada como um risco ambiental mínimo, mas não se esqueça de realizar quaisquer etapas com este produto químico em um armário de biossegurança apropriado.

wet-spinning-based-molding-process-of-gelatin-for-tissue-regeneration

Research

JoVE Journal

Bioengineering

Expression, Isolation, and Purification of Soluble and Insoluble Biotinylated Proteins for Nerve Tissue Regeneration

Recombinant protein engineering has utilized Escherichia coli (E. coli) expression systems for nearly 4 decades, and today E. coli is still the most widely used host organism. The flexibility of the system allows for the addition of moieties such as a biotin tag (for streptavidin interactions) and larger functional proteins like green fluorescent protein or cherry red protein. Also, the integration of unnatural amino acids like metal ion chelators, uniquely reactive functional groups, spectroscopic probes, and molecules imparting post-translational modifications has enabled better manipulation of protein properties and functionalities. As a result this technique creates customizable fusion proteins that offer significant utility for various fields of research. More specifically, the biotinylatable protein sequence has been incorporated into many target proteins because of the high affinity interaction between biotin with avidin and streptavidin. This addition has aided in enhancing detection and purification of tagged proteins as well as opening the way for secondary applications such as cell sorting. Thus, biotin-labeled molecules show an increasing and widespread influence in bioindustrial and biomedical fields. For the purpose of our research we have engineered recombinant biotinylated fusion proteins containing nerve growth factor (NGF) and semaphorin3A (Sema3A) functional regions. We have reported previously how these biotinylated fusion proteins, along with other active protein sequences, can be tethered to biomaterials for tissue engineering and regenerative purposes. This protocol outlines the basics of engineering biotinylatable proteins at the milligram scale, utilizing&#160; a T7 lac inducible vector and E. coli expression hosts, starting from transformation to scale-up and purification.

Developing biotinylatable fusion proteins has many potential applications in various fields of research. Recombinant protein engineering is a straight forward procedure that is cost-effective, providing high yields of custom-designed proteins.

Expressão, isolamento e purificação do solúveis e insolúveis biotinilados Proteínas de Tecido Nervoso Regeneração

Recombinant protein engineering has utilized Escherichia coli (E. coli) expression systems for nearly 4 decades, and today E. coli is still the most ...

Bioengenharia

Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding

Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications.

We have devised a method for low-cost and rapid prototyping of liquid elastomer rubber injection molded devices by using fused deposition modeling 3D printers for mold design and a modified desiccator as a liquid injection system.

Prototipagem rápida e de baixo custo de Dispositivos Médicos Usando 3D impresso moldes para moldagem por injeção líquida

Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using ...

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.

Engenharia 3D celularizados Colágeno Gel para Vascular Regeneração Tecidual

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

Adapting the Electrospinning Process to Provide Three Unique Environments for a Tri-layered In Vitro Model of the Airway Wall

Electrospinning is a highly adaptable method producing porous 3D fibrous scaffolds that can be exploited in in vitro cell culture. Alterations to intrinsic parameters within the process allow a high degree of control over scaffold characteristics including fiber diameter, alignment and porosity. By developing scaffolds with similar dimensions and topographies to organ- or tissue-specific extracellular matrices (ECM), micro-environments representative to those that cells are exposed to in situ can be created. 
The airway bronchiole wall, comprised of three main micro-environments, was selected as a model tissue. Using decellularized airway ECM as a guide, we electrospun the non-degradable polymer, polyethylene terephthalate (PET), by three different protocols to produce three individual electrospun scaffolds optimized for epithelial, fibroblast or smooth muscle cell-culture. Using a commercially available bioreactor system, we stably co-cultured the three cell-types to provide an in vitro model of the airway wall over an extended time period.
This model highlights the potential for such methods being employed in in vitro diagnostic studies investigating important inter-cellular cross-talk mechanisms or assessing novel pharmaceutical targets, by providing a relevant platform to allow the culture of fully differentiated adult cells within 3D, tissue-specific environments.

Adapting the Electrospinning Process to Provide Three Unique Environments for a Tri-layered In Vitro Model of the Airway Wall

Advancements in biomaterial technologies enable the development of three-dimensional multi-cell-type constructs. We have developed electrospinning protocols to produce three individual scaffolds to culture the main structural cells of the airway to provide a 3D in vitro model of the airway bronchiole wall.

Adaptação do Processo Electrospinning para fornecer três ambientes únicos para um Tri-camadas<em&gt; In Vitro</em&gt; Modelo da parede das vias aéreas

Electrospinning is a highly adaptable method producing porous 3D fibrous scaffolds that can be exploited in in vitro cell culture. Alterations to ...

Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in complex mixtures. It is often used to analyze gasoline, jet fuel, diesel, bio-diesel and the organic fraction of bio-crude/bio-oil. In most of those analyses, the first dimension of separation is non-polar, followed by a polar separation. The aqueous fractions of bio-crude and other aqueous samples from biofuels production have been examined with similar column combinations. However, sample preparation techniques such as derivatization, solvent extraction, and solid-phase extraction were necessary prior to analysis. In this study, aqueous fractions obtained from the hydrothermal liquefaction of algae were characterized by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry without prior sample preparation techniques using a polar separation in the first dimension followed by a non-polar separation in the second. Two-dimensional plots from this analysis were compared with those obtained from the more traditional column configuration. Results from qualitative characterization of the aqueous fractions of algal bio-crude are discussed in detail. The advantages of using a polar separation followed by a non-polar separation for characterization of organics in aqueous samples by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry are highlighted.

A two-dimensional gas chromatography-time-of-flight mass spectrometry method is described for characterization of the aqueous fraction of bio-crude produced from hydrothermal liquefaction of algae. This protocol can also be employed to analyze the aqueous fraction of liquid products from fast pyrolysis, catalytic fast pyrolysis, catalytic deoxygenation and hydro-treating.

Caracterização qualitativa da fração aquosa de Hydrothermal Liquefação de algas por cromatografia gasosa 2D com Time-of-flight Espectrometria de Massa

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in ...

Alternating Magnetic Field-Responsive Hybrid Gelatin Microgels for Controlled Drug Release

Magnetically-responsive nano/micro-engineered biomaterials that enable a tightly controlled, on-demand drug delivery have been developed as new types of smart soft devices for biomedical applications. Although a number of magnetically-responsive drug delivery systems have demonstrated efficacies through either in vitro proof of concept studies or in vivo preclinical applications, their use in clinical settings is still limited by their insufficient biocompatibility or biodegradability. Additionally, many of the existing platforms rely on sophisticated techniques for their fabrications. We recently demonstrated the fabrication of biodegradable, gelatin-based thermo-responsive microgel by physically entrapping poly(N-isopropylacrylamide-co-acrylamide) chains as a minor component within a three-dimensional gelatin network. In this study, we present a facile method to fabricate a biodegradable drug release platform that enables a magneto-thermally triggered drug release. This was achieved by incorporating superparamagnetic iron oxide nanoparticles and thermo-responsive polymers within gelatin-based colloidal microgels, in conjunction with an alternating magnetic field application system.

We present a facile method to fabricate a biodegradable gelatin-based drug release platform that is magneto-thermally responsive. This was achieved by incorporating superparamagnetic iron oxide nanoparticles and poly(N-isopropylacrylamide-co-acrylamide) within a spherical gelatin micro-network crosslinked by genipin, in conjunction with an alternating magnetic field application system.

Alternando microgéis de gelatina híbrido Campo-Responsive magnética para controlada de fármacos de libertação

Magnetically-responsive nano/micro-engineered biomaterials that enable a tightly controlled, on-demand drug delivery have been developed as new types of ...

A Paired Bead and Magnet Array for Molding Microwells with Variable Concave Geometries

A spheroid culture is a useful tool for understanding cellular behavior in that it provides an in vivo-like three-dimensional environment. Various spheroid production methods such as non-adhesive surfaces, spinner flasks, hanging drops, and microwells have been used in studies of cell-to-cell interaction, immune-activation, drug screening, stem cell differentiation, and organoid generation. Among these methods, microwells with a three-dimensional concave geometry have gained the attention of scientists and engineers, given their advantages of uniform-sized spheroid generation and the ease with which the responses of individual spheroids can be monitored. Even though cost-effective methods such as the use of flexible membranes and ice lithography have been proposed, these techniques incur serious drawbacks such as difficulty in controlling the pattern sizes, achievement of high aspect ratios, and production of larger areas of microwells. To overcome these problems, we propose a robust method for fabricating concave microwells without the need for complex high-cost facilities. This method utilizes a 30 x 30 through-hole array, several hundred micrometer-order steel beads, and magnetic force to fabricate 900 microwells in a 3 cm x 3 cm polydimethylsiloxane (PDMS) substrate. To demonstrate the applicability of our method to cell biological applications, we cultured adipose stem cells for 3 days and successfully produced spheroids using our microwell platform. In addition, we performed a magnetostatic simulation to investigate the mechanism, whereby magnetic force was used to trap the steel beads in the through-holes. We believe that the proposed microwell fabrication method could be applied to many spheroid-based cellular studies such as drug screening, tissue regeneration, stem cell differentiation, and cancer metastasis.

This manuscript introduces a robust method of fabricating concave microwells without the need for complex high-cost facilities. Using magnetic force, steel beads, and a through-hole array, several hundred microwells were formed in a 3 cm x 3 cm polydimethylsiloxane (PDMS) substrate.

Um grânulo emparelhado e matriz de ímã para moldagem micropoços com geometrias côncavas variáveis

A spheroid culture is a useful tool for understanding cellular behavior in that it provides an in vivo-like three-dimensional environment. Various ...

Three-dimensional Tissue Engineered Aligned Astrocyte Networks to Recapitulate Developmental Mechanisms and Facilitate Nervous System Regeneration

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to replace lost neurons and regenerate axonal pathways. However, during nervous system development, neuronal migration and axonal extension often occur along pathways formed by other cells, referred to as &#34;living scaffolds&#34;. Seeking to emulate these mechanisms and to design a strategy that circumvents the inhibitory environment of the CNS, this manuscript presents a protocol to fabricate tissue engineered astrocyte-based &#34;living scaffolds&#34;. To create these constructs, we employed a novel biomaterial encasement scheme to induce astrocytes to self-assemble into dense three-dimensional bundles of bipolar longitudinally-aligned somata and processes. First, hollow hydrogel micro-columns were assembled, and the inner lumen was coated with collagen extracellular-matrix. Dissociated cerebral cortical astrocytes were then delivered into the lumen of the cylindrical micro-column and, at a critical inner diameter of &#60;350 &#181;m, spontaneously self-aligned and contracted to produce long fiber-like cables consisting of dense bundles of astrocyte processes and collagen fibrils measuring &#60;150 &#181;m in diameter yet extending several cm in length. These engineered living scaffolds exhibited &#62;97% cell viability and were virtually exclusively comprised of astrocytes expressing a combination of the intermediate filament proteins glial-fibrillary acidic protein (GFAP), vimentin, and nestin. These aligned astrocyte networks were found to provide a permissive substrate for neuronal attachment and aligned neurite extension. Moreover, these constructs maintain integrity and alignment when extracted from the hydrogel encasement, making them suitable for CNS implantation. These preformed constructs structurally emulate key cytoarchitectural elements of naturally occurring glial-based &#34;living scaffolds&#34; in vivo. As such, these engineered living scaffolds may serve as test-beds to study neurodevelopmental mechanisms in vitro or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding following CNS degeneration in vivo.

We showcase the development of self-assembled, three-dimensional bundles of longitudinally aligned astrocytic somata and processes within a novel biomaterial encasement. These engineered &#34;living scaffolds&#34;, exhibiting micron-scale diameter yet extending centimeters in length, may serve as test-beds to study neurodevelopmental mechanisms or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding.

Engenharia de Tecido Tridimensional de Redes de Astrócitos Alinhadas para Recapitular Mecanismos de Desenvolvimento e Facilitar a Regeneração do Sistema Nervoso

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to ...

Patterning the Geometry of Human Embryonic Stem Cell Colonies on Compliant Substrates to Control Tissue-Level Mechanics

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that correspond to primary germ layer formation during embryogenesis. Thus, these cells represent a powerful tool with which to examine the mechanisms that drive early human development. We have developed a method to culture human embryonic stem cells in confined colonies on compliant substrates that provides control over both the geometry of the colonies and their mechanical environment in order to recapitulate the physical parameters that underlie embryogenesis. The key feature of this method is the ability to generate polyacrylamide hydrogels with defined patterns of extracellular matrix ligand at the surface to promote cell attachment. This is achieved by fabricating stencils with the desired geometric patterns, using these stencils to create patterns of extracellular matrix ligand on glass coverslips, and transferring these patterns to polyacrylamide hydrogels during polymerization. This method is also compatible with traction force microscopy, allowing the user to measure and map the distribution of cell-generated forces within the confined colonies. In combination with standard biochemical assays, these measurements can be used to examine the role mechanical cues play in fate specification and morphogenesis during early human development.

Extracellular matrix ligands can be patterned onto polyacrylamide hydrogels to enable the culture of human embryonic stem cells in confined colonies on compliant substrates. This method can be combined with traction force microscopy and biochemical assays to examine the interplay between tissue geometry, cell-generated forces, and fate specification.

Padronização da geometria de colônias de células-tronco embrionárias humanas em substratos compatíveis para controlar a mecânica de nível de tecido

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that ...

Protocols of 3D Bioprinting of Gelatin Methacryloyl Hydrogel Based Bioinks

Gelatin methacryloyl (GelMA) has become a popular biomaterial in the field of bioprinting. The derivation of this material is gelatin, which is hydrolyzed from mammal collagen. Thus, the arginine-glycine-aspartic acid (RGD) sequences and target motifs of matrix metalloproteinase (MMP) remain on the molecular chains, which help achieve cell attachment and degradation. Furthermore, formation properties of GelMA are versatile. The methacrylamide groups allow a material to become rapidly crosslinked under light irradiation in the presence of a photoinitiator. Therefore, it makes great sense to establish suitable methods for synthesizing three-dimensional (3D) structures with this promising material. However, its low viscosity restricts GelMA's printability. Presented here are methods to carry out 3D bioprinting of GelMA hydrogels, namely the fabrication of GelMA microspheres, GelMA fibers, GelMA complex structures, and GelMA-based microfluidic chips. The resulting structures and biocompatibility of the materials as well as the printing methods are discussed. It is believed that this protocol may serve as a bridge between previously applied biomaterials and GelMA as well as contribute to the establishment of GelMA-based 3D architectures for biomedical applications.

Presented here is a method for the 3D bioprinting of gelatin methacryloyl.

Protocolos de bioimpressão 3D de bioinks baseados em hidrogel de gelatina

Gelatin methacryloyl (GelMA) has become a popular biomaterial in the field of bioprinting. The derivation of this material is gelatin, which is hydrolyzed ...