Name: murine model of femoral artery wire injury with implantation of a perivascular drug delivery patch
Uploaded: 2015-02-10T14:00:00.000+00:00
Duration: 7 min 5 s
Description: Watch this Scientific Journal Video about Murine Model of Femoral Artery Wire Injury with Implantation of a Perivascular Drug Delivery Patch at JoVE.com

The authors would like to acknowledge support through the American Heart Association (10SDG2630139), the Welch Foundation and through the NIH Director&#8217;s New Innovator Grant (1DP2 OD008716-01). The authors would like to thank the services provided by the ICMB (Institute of Cellular and Molecular Biology) core facility and TherapeUTex at University of Texas at Austin.

NOTA: Todos os métodos mostrados neste protocolo ter sido aprovado pelo Comitê de Uso e Cuidado Animal Institucional. 1. Preparação da Tabela cirúrgico <ol><li> Configure a almofada de aquecimento com recirculação de água quente sobre a mesa cirúrgica, sob o microscópio de dissecação. Coloque a placa de base de aço inoxidável para a almofada de aquecimento. Coloque um pano absorvente estéril na placa de base e almofada de aquecimento. </li><li> Organizar instrumentos cirúrgicos estéreis sobre um pano absorvente estéril adjacente. Reunir duas pinças de ponta fina ângulo, duas pinças anguladas, três pinça hemostática, dois fios retratores, pequenas tesouras cirúrgicas, micro-tesoura, fio uma angioplastia (diâmetro de 0,15 polegadas) e três segmentos de sutura 6.0 seda de 6 polegadas . </li><li> Dobre a rodada final do fio de angioplastia para coincidir com a curvatura da artéria femoral. Isso tornará mais fácil para avançar o fio durante a cirurgia. </li></ol> 2. Preparação deRato para Cirurgia <ol><li> Anestesiar um rato por inalação contínua de 2,5% de isoflurano. Certifique-se de monitorar o status do animal durante todo o procedimento. Realizar um teste pitada do pé do mouse para confirmar que ele está totalmente anestesiado. Certifique-se de que o animal não se mover quando o teste do beliscão é administrada. </li><li> Aplique uma pomada lubrificante para os olhos do animal para evitar a dessecação. Fixe o animal em decúbito dorsal para a almofada absorvente usando fita cirúrgica. Continue a administração de 2,5% de isoflurano via nariz cone. </li><li> Usar um creme depilatório, retire a pele da perna e do abdômen para a mid-line. Lavar a pele com água. Depilação pode ser realizada um dia antes da cirurgia. Note-se que o tratamento com o creme excessiva pode levar a irritação da pele. </li><li> Imediatamente antes da cirurgia, aplica povidona-iodo na área depilada com um aplicador de ponta de algodão para esterilizar a pele. Lavar a pele depilada com etanol 70% e secocom um cotonete estéril. Repita 3 vezes. </li><li> Administrar uma dose pré-operatória de 5 mg / kg de carprofeno, por injecção subcutânea. </li></ol> 3. Isolamento da Artéria Femoral <ol><li> Com uma tesoura pequena cirurgia, fazer uma incisão curva na pele sobre a artéria femoral. Sem rodeios dissecar e proteger os tecidos circundantes com afastadores fixadores retrator magnética para localizar a artéria femoral. Umedeça os tecidos periodicamente, utilizando solução salina para irrigação Aplicar soro fisiológico usando um aplicador de algodão estéril. </li><li> Isolar a artéria femoral com a pinça. Separe cuidadosamente o nervo do feixe vascular usando uma pinça de ponta fina. Evite punção da veia, e não danificar o nervo. Empurre o nervo longe do pacote para evitar estimulá-lo. </li><li> Suavemente separar a veia femoral a partir da artéria femoral, localizando a bifurcação femoral. A região da bifurcação é especialmente difícil para dissecar. </li><li> Posterior à bifurcação, um laço de sutura de seda 6.0 sob a artéria femoral e seguro com uma pinça hemostática. Esta sutura proximal será utilizada para restringir o fluxo de sangue na artéria. NOTA: Há uma ligeira variação nos laços ao executar o método de ligação em relação ao método de cauterização (veja a Figura 1 e Figura 2). </li><li> Distalmente à bifurcação, malha 6,0 sutura de seda por baixo da artéria femoral e seguro com uma pinça hemostática. Este distais auxiliares de sutura no posicionamento da artéria. </li><li> Loop duas suturas sob o ramo muscular da artéria femoral, pré-amarrá-los e prenda com uma pinça hemostática. Lembre-se de umedecer os tecidos com solução salina. Se a realização do método cautério de lesão fio, apenas uma sutura em loop é necessário no ramo muscular. </li></ol> 4. Desempenho da artéria femoral Injury Fio <ol><li> Restringir o fluxo de sangue na artéria femoral, puxando o fio de sutura proximal. Ligeiramente puxar o Hemost distala pinça hemostática e garantir a filial para expor o local para a arteriotomy. Ligadura do ramo muscular amarrando a sutura em torno dele. NOTA: Levantar a artéria para cima vai mais eficaz restringir o fluxo de sangue do que puxar horizontalmente sozinho. </li><li> Sever do pequeno ramo com cautério entre as duas suturas. Usando micro-tesoura, realizar uma arteriotomy no ramo lateral da bifurcação. Use uma pinça balanceada com um rolo de fita cirúrgica para estabilizar os micro-tesoura. </li><li> Confirmar a presença do arteriotomy usando uma pinça de ponta fina. Levante cuidadosamente a abertura do arteriotomy com a pinça. Introduzir a extremidade arredondada do fio no arteriotomy usando uma pinça. Para facilitar o avanço do arame, adicionar uma ou duas gotas de lidocaína à região, utilizando uma seringa. </li><li> Quando o fio atinge o fio de sutura proximal, libertar o fio de sutura e ajustá-lo de modo que ele não pode impedir o avanço do fio. Insira o fio até que ela não pode avançar ainda mais. A ponta do the fio deve parar na região do ligamento inguinal. </li><li> Permitir que o fio de permanecer na artéria femoral para um minuto. Após um minuto, retrair e avançar o fio em um movimento de corte de dez vezes para ferir e desnudar o endotélio da artéria femoral. Para uma lesão de menor gravidade, diminuir o número de vezes que o fio é puxado para dentro e para fora da artéria ou deixar o fio na artéria para apenas 1 min. </li><li> Recolha o fio lentamente. Quando a rodada final do fio passou a sutura proximal, restringir o fluxo na artéria puxando o fio de sutura proximal. Recolha o fio completamente. </li></ol> 5. ligando o Poder Muscular <ol><li> Aperte a sutura restante no ramo muscular. Isto irá prevenir o sangramento do arteriotomy. Retorno de fluxo para o ramo muscular, e confirme que o sangue não está vazando a partir dele. Corte as extremidades das suturas no ramo muscular. </li></ol> 6. Método Alternativo: Localizada Cauzação da arteriotomia NOTA: pode ser tomado Uma abordagem alternativa para evitar a ligadura do ramo muscular e permitir o acesso vascular através da artéria femoral principal maior. <ol><li> A partir de 4.1, para restringir o fluxo na artéria femoral em puxando o fio de sutura proximal. Puxar o fio de sutura distal e segurar fio de sutura ligeiramente o ramo muscular para expor o local para a arteriotomia (Figura 1 e Figura 2). </li><li> Usando micro-tesoura, realizar uma arteriotomy no ponto ramo da artéria femoral eo ramo muscular. Se a incisão é feita na parte lateral da artéria, pode ser mais fácil para cauterizar. Use uma pinça balanceada com um rolo de fita cirúrgica para estabilizar os micro-tesoura. </li><li> Para testar o sucesso da cauterização, para restaurar o fluxo da artéria femoral, soltando a sutura proximal. Se o sangramento ocorre a partir do arteriotomy, repita o cautério. Se o cautério for bem sucedida, o fluxo de sangue será rearmazenado distal à arteriotomia. </li><li> Introduzir o fio e executar a lesão fio conforme descrito no capítulo 4. </li><li> Continuar a restringir o fluxo de sangue na artéria femoral. Aqueça uma cauterização de ponta fina, pelo menos, 6 centímetros de distância do mouse. Como o cautério arrefece, aplicar uma camada fina lado da arteriotomia para fechar a incisão. </li><li> Para testar o sucesso da cauterização, para restaurar o fluxo da artéria femoral, soltando a sutura proximal. Se o sangramento ocorre a partir do arteriotomy, repita o cautério. Se a cauterização é bem sucedido, o fluxo de sangue vai ser restaurada distal à arteriotomia. Retire o proximal temporária e laços distais. </li></ol> 7. Implantação de perivascular Drogas patch Entrega <ol><li> Criar um remendo perivascular droga pode ser criado como descrito em estudos anteriores 11 ou utilizando métodos semelhantes. Blunt os cantos da região a barreira do patch entrega da droga usando uma tesoura esterilizada </li><li> Coloque o pat entrega da drogach para a artéria femoral feridos com o lado de libertação de droga voltado para a artéria. Se necessário, utilize uma pinça para melhorar a posição do patch. </li></ol> 8. Wound Encerramento e Recuperação <ol><li> Fechar a ferida com uma sutura interrompida simples consistindo de nós quadrados. Uma sutura descontínua prolonga o fechamento da ferida em caso de o animal tenta remover o fio de sutura. </li><li> Desligue a anestesia e retirar o animal do set up. Permitir que o animal possa recuperar na almofada de aquecimento. </li><li> Continue a acompanhar a recuperação do mouse. Verifique o local da incisão a cada dia para garantir que permanece fechado. Para o tratamento de dor pós-cirúrgica, administrar uma injecção subcutânea de 5 mg / kg de carprofeno cada 12 horas após a cirurgia e, em seguida, a cada 12 h durante 2 dias. Se a dor continua para além dos primeiros dois dias, consulte um veterinário para obter instruções sobre mais medicação para dor. </li></ol> 9. Artérias colheita femoral para Histologia <ol><li> Aos 28 dias pós-cirurgia, realizar o dióxido de carbono a eutanásia no mouse. NOTA: O caudal adequado de dióxido de carbono deve deslocar 10-30% da câmara por minuto e irá variar dependendo do tamanho da câmara usada. Corte do diafragma e punção cardíaca deve ser realizada como um método secundário de eutanásia. </li><li> Fixe o mouse na posição em decúbito dorsal com fita cirúrgica. Faça uma incisão sobre a artéria femoral, onde a incisão cirúrgica inicial foi feito. </li><li> Para tanto a artéria feridos ea artéria ileso da perna contralateral, sem rodeios dissecar e garantir tecidos circundantes com afastadores e fixadores retrator magnéticos para localizar a artéria femoral. Umedeça os tecidos periodicamente, utilizando solução salina para a irrigação. Aplicar soro fisiológico usando um aplicador de algodão estéril. Tome cuidado para não danificar a artéria. </li><li> Após a artéria femoral foi isolada a partir do local da arteriotomia original para a aorta abdominal, amarrar um segmento de fio de seda perto do local original do arteriotomy. Esta sutura vai ajudar a identificar a extremidade mais distai da artéria femoral e facilitar a manipulação da amostra. </li><li> Usando a tesoura micro-dissecação para extirpar a artéria femoral. Faça uma incisão distal à sutura. Adicione outro incisão na extremidade oposta da artéria femoral, ao lado da aorta abdominal. </li><li> Transferir a artéria excisada para uma placa de Petri de vidro contendo solução salina. Dissecção da artéria mais para remover o excesso de tecido conjuntivo ou de gordura. Remova cuidadosamente o sangue do lúmen por lavagem com soro fisiológico. </li><li> Transfira a artéria de um frasco de formol a 10% tamponado. Armazenar o frasco a 4 ° C com agitação suave durante 48 horas. </li><li> Transferir a artéria fixada a 70% de etanol, para armazenar até ser processado para histologia. </li><li> Incorporar a artéria em blocos de parafina e secção dos blocos para a coloração. </li><li> Execute coloração histoquímica e immunochemical para avaliar a extensão da lesão e da íntima hyperplasia. NOTA: Para obter os resultados representativos, usamos Hematoxilina e Eosina para visualizar os núcleos e morfologia geral ou Pentachrome mancha de um Movat visualizar a lamelas elásticas e outros componentes arteriais. </li></ol>

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	<li>Hoffmann, R., Mintz, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+in-stent+restenosis+-+predictors,+treatment+and+prevention.">Coronary in-stent restenosis - predictors, treatment and prevention.</a> Eur Heart J. 21 (21), 1739-1749 (2000).</li><li>Erbel, R., 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=Coronary-artery+stenting+compared+with+balloon+angioplasty+for+restenosis+after+initial+balloon+angioplasty.+Restenosis+Stent+Study+Group.">Coronary-artery stenting compared with balloon angioplasty for restenosis after initial balloon angioplasty. Restenosis Stent Study Group.</a> N Engl J Med. 339 (23), 1672-1678 (1998).</li><li>Farooq, V., Gogas, B. D., Serruys, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Restenosis:+delineating+the+numerous+causes+of+drug-eluting+stent+restenosis.">Restenosis: delineating the numerous causes of drug-eluting stent restenosis.</a> Circ Cardiovasc Interv. 4 (2), 195-205 (2011).</li><li>Iqbal, J., Gunn, J., Serruys, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+stents:+historical+development,+current+status+and+future+directions.">Coronary stents: historical development, current status and future directions.</a> Br Med Bull. 106, 193-211 (2013).</li><li>Garg, S., Serruys, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+stents:+current+status.">Coronary stents: current status.</a> J Am Coll Cardiol. 56 (10 Suppl), S1-S42 (2010).</li><li>Park, S. J., Kim, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+status+of+percutaneous+coronary+intervention+with+drug-eluting+stents+in+Asia.">Current status of percutaneous coronary intervention with drug-eluting stents in Asia.</a> Circulation. 118 (25), 2730-2737 (2008).</li><li>Alfonso, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+drug-eluting+stent+restenosis+the+new+pilgrimage:+quo+vadis.">Treatment of drug-eluting stent restenosis the new pilgrimage: quo vadis.</a> J Am Coll Cardiol. 55 (24), 2717-2720 (2010).</li><li>Dake, M. D., 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=Paclitaxel-eluting+stents+show+superiority+to+balloon+angioplasty+and+bare+metal+stents+in+femoropopliteal+disease:+twelve-month+Zilver+PTX+randomized+study+results.">Paclitaxel-eluting stents show superiority to balloon angioplasty and bare metal stents in femoropopliteal disease: twelve-month Zilver PTX randomized study results.</a> Circ Cardiovasc Interv. 4 (5), 495-504 (2011).</li><li>Bosiers, M., 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=Results+of+the+Protege+EverFlex+200-mm-long+nitinol+stent+(ev3)+in+TASC+C+and+D+femoropopliteal+lesions.">Results of the Protege EverFlex 200-mm-long nitinol stent (ev3) in TASC C and D femoropopliteal lesions.</a> J Vasc Surg. 54 (4), 1042-1050 (2011).</li><li>Duda, S. H., 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=Drug-eluting+and+bare+nitinol+stents+for+the+treatment+of+atherosclerotic+lesions+in+the+superficial+femoral+artery:+long-term+results+from+the+SIROCCO+trial.">Drug-eluting and bare nitinol stents for the treatment of atherosclerotic lesions in the superficial femoral artery: long-term results from the SIROCCO trial.</a> J Endovasc Ther. 13 (6), 701-710 (2006).</li><li>Kumar, A., Lindner, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Remodeling+with+neointima+formation+in+the+mouse+carotid+artery+after+cessation+of+blood+flow.">Remodeling with neointima formation in the mouse carotid artery after cessation of blood flow.</a> Arterioscler Thromb Vasc Biol. 17 (10), 2238-2244 (1997).</li><li>Sata, M., 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=A+mouse+model+of+vascular+injury+that+induces+rapid+onset+of+medial+cell+apoptosis+followed+by+reproducible+neointimal+hyperplasia.">A mouse model of vascular injury that induces rapid onset of medial cell apoptosis followed by reproducible neointimal hyperplasia.</a> J Mol Cell Cardiol. 32 (11), 2097-2104 (2000).</li><li>Roque, M., 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=Mouse+model+of+femoral+artery+denudation+injury+associated+with+the+rapid+accumulation+of+adhesion+molecules+on+the+luminal+surface+and+recruitment+of+neutrophils.">Mouse model of femoral artery denudation injury associated with the rapid accumulation of adhesion molecules on the luminal surface and recruitment of neutrophils.</a> Arterioscler Thromb Vasc Biol. 20 (2), 335-342 (2000).</li><li>Lindner, V., Fingerle, J., Reidy, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+model+of+arterial+injury.">Mouse model of arterial injury.</a> Circ Res. 73 (5), 792-796 (1993).</li><li>Edelman, E. R., Adams, D. H., Karnovsky, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+controlled+adventitial+heparin+delivery+on+smooth+muscle+cell+proliferation+following+endothelial+injury.">Effect of controlled adventitial heparin delivery on smooth muscle cell proliferation following endothelial injury.</a> Proc Natl Acad Sci U S A. 87 (10), 3773-3777 (1990).</li><li>Stemerman, M. B., Ross, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+arteriosclerosis.+I.+Fibrous+plaque+formation+in+primates,+an+electron+microscope+study.">Experimental arteriosclerosis. I. Fibrous plaque formation in primates, an electron microscope study.</a> J Exp Med. 136 (4), 769-789 (1972).</li><li>Brouchet, L., 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=Estradiol+accelerates+reendothelialization+in+mouse+carotid+artery+through+estrogen+receptor-alpha+but+not+estrogen+receptor-beta.">Estradiol accelerates reendothelialization in mouse carotid artery through estrogen receptor-alpha but not estrogen receptor-beta.</a> Circulation. 103 (3), 423-428 (2001).</li><li>Filipe, C., 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=Estradiol+accelerates+endothelial+healing+through+the+retrograde+commitment+of+uninjured+endothelium.">Estradiol accelerates endothelial healing through the retrograde commitment of uninjured endothelium.</a> Am J Physiol Heart Circ Physiol. 294 (6), H2822-H2830 (2008).</li><li>Feuls, R., 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=Microvascular+denudation+of+the+femoral+artery+of+the+mouse+as+a+model+for+restenosis.">Microvascular denudation of the femoral artery of the mouse as a model for restenosis.</a> Rofo. 175 (7), 952-957 (2003).</li><li>Holt, A. W., Tulis, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+Rat+and+Mouse+Carotid+Artery+Surgery:+Injury+&amp;+Remodeling+Studies.">Experimental Rat and Mouse Carotid Artery Surgery: Injury &amp; Remodeling Studies.</a> ISRN Minim Invasive Surg. 2013, (2013).</li><li>Iafrati, M. D., 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=Estrogen+inhibits+the+vascular+injury+response+in+estrogen+receptor+alpha-deficient+mice.">Estrogen inhibits the vascular injury response in estrogen receptor alpha-deficient mice.</a> Nat Med. 3 (5), 545-548 (1997).</li><li>Sullivan, T. R., 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=Estrogen+inhibits+the+response-to-injury+in+a+mouse+carotid+artery+model.">Estrogen inhibits the response-to-injury in a mouse carotid artery model.</a> J Clin Invest. 96 (5), 2482-2488 (1995).</li><li>Yin, Y., Zhao, X., Fang, Y., Huang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carotid+artery+wire+injury+mouse+model+with+a+nonmicrosurgical+procedure.">Carotid artery wire injury mouse model with a nonmicrosurgical procedure.</a> Vascular. 18 (4), 221-226 (2010).</li><li>Nam, D., 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=Partial+carotid+ligation+is+a+model+of+acutely+induced+disturbed+flow,+leading+to+rapid+endothelial+dysfunction+and+atherosclerosis.">Partial carotid ligation is a model of acutely induced disturbed flow, leading to rapid endothelial dysfunction and atherosclerosis.</a> Am J Physiol Heart Circ Physiol. 297 (4), H1535-H1543 (2009).</li><li>Nam, D., 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=A+model+of+disturbed+flow-induced+atherosclerosis+in+mouse+carotid+artery+by+partial+ligation+and+a+simple+method+of+RNA+isolation+from+carotid+endothelium.">A model of disturbed flow-induced atherosclerosis in mouse carotid artery by partial ligation and a simple method of RNA isolation from carotid endothelium.</a> J Vis Exp. (40), (2010).</li><li>Kuhlmann, M. T., 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=Implantation+of+a+carotid+cuff+for+triggering+shear-stress+induced+atherosclerosis+in+mice.">Implantation of a carotid cuff for triggering shear-stress induced atherosclerosis in mice.</a> J Vis Exp. (59), (2012).</li><li>Carmeliet, P., 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=Vascular+wound+healing+and+neointima+formation+induced+by+perivascular+electric+injury+in+mice.">Vascular wound healing and neointima formation induced by perivascular electric injury in mice.</a> Am J Pathol. 150 (2), 761-776 (1997).</li></ol>

We have presented a method for performing vascular injury in mice and delivery therapeutic compounds to the injured region through a perivascular cuff. The ligation method for femoral and carotid arteries has been described in conventional methods papers and characterized extensively11-14,19-23 and we present an alternative method for achieving the same vascular injury that is less technically demanding procedure that can often be used in younger mice. One of the chief advantages of the using a mouse wire injury model with a perivascular patch is that it allows the use of genetically modified mice or murine models of disease. The endovascular manipulation of small arteries is technically demanding and this aspect has motivated the creation of models that create injury through a number of extravascular methods including ligation,11,24,25 perivascular cuffing26 and electric shock.27 In our procedures, a contralateral sham surgery can be used as a control by performing the protocol without the wire injury or, alternatively, non-operated control arteries can be used. The critical steps within the protocol are the following: (1) the surgical cut down and dissection of the femoral artery from surrounding structures, (2) the formation of the arteriotomy, (3) performance of the wire injury, (4) closure of the arteriotomy and (5) implantation of the perivascular cuff. Below we will review the major steps and address potential pitfalls in their performance. 
For the surgical cut down, the major challenge is the separation of the femoral artery from the femoral vein. Care should be taken at this stage, as it is easy to cause bleeding during the separation and the vein tears easily in comparison to the artery. Using forceps to blunt dissect and remove adventitia surround the artery and vein can help this process (see techniques shown in the video). Also, the artery may have branches underneath that can be torn if an overly aggressive technique is used. 
For the formation of the arteriotomy and wire injury, it is critical to use high quality microsurgical scissors. It is often helpful to cut at a 45-degree angle to the axis of the artery and to stabilize the cut with forceps as shown in the video. Too much or too little tension on the artery can make cutting difficult and it is sometimes helpful pull the distal tie before the proximal tie to fill the artery with blood to aid in the performing the arteriotomy. After the cut, opening the hole with the closed point of the scissors or forceps can aid in allowing entry of the wire. The size of the arteriotomy should cut approximately half way through the artery. Again, too much tension on the artery will make insertion of the wire difficult and may tear the vessel. A low to moderate level of tension should be used with the ties. When inserting the wire a slight twisting motion can be helpful but too much twisting will cause the artery to seize, preventing advancement of the wire.
A key step in performing our alternative method is the controlled local cautery that seals the vessel without blocking flow. The cautery should be heated away from the tissue and then touched to the side of the artery. Heating with the cautery while touching the vessel will burn surrounding tissues including the vein and femoral artery branches. One potential limitation of this technique is that if the arteries are not consistently cauterized there may be variations in the flow following the surgery or in the amount of inflammation caused by the burn. Analysis of the artery away from this region and consistent technique can minimize the potential impact of these limitations. We hope this alternative method will make the wire injury surgery more accessible and reduce the need for older mice for vascular injury studies.

Arterial injury and inflammation caused by angioplasty and stent implantation can induce neointimal hyperplasia that contributes to the thickening of the arterial wall, a process known as restenosis.1,2 The formation of restenosis is major mode of failure for interventions such as angioplasty and stenting with bare metal stents.3 Due to recent concerns with the inhibition of vascular healing in arteries treated with drug eluting stents, there is also a need to find compounds that can inhibit restenosis while maintaining vascular healing and re-endothelialization.4-7 In addition, while stents have had success in the coronary vasculature, percutaneous interventions of all types in the peripheral arteries continue to fail at a higher rate due to restenosis.8-10 Mouse models of surgical interventions allow the use of powerful genetic manipulations that can provide mechanistic insight into the mechanisms underlying the failure of clinical therapies and can provide an initial test bed for compounds to inhibit intimal hyperplasia. 
Here, we describe a mouse model of vascular injury that allows the testing of therapeutic compounds to inhibit neointimal hyperplasia and assess whether their effects on re-endothelialization following endothelial denudation. A key challenge in executing vascular injury in mice is the technical skill needed to obtain vascular access and to restore flow to the injured artery following the wire injury. For this reason, simple arterial ligation models have been used to study neointimal hyperplasia in mice that do not require endovascular manipulations but are easier to implement.11 However, this type of surgical model differs substantially from the mechanical and biological aspects of a percutaneous intervention, lacking key aspects including arterial wall stretch, endothelial denudation and luminal blood flow following injury. 
We present two methods for obtaining and closing vascular access for wire injury of the femoral artery in mice. The first technique is the conventional method described by several groups previously and uses vascular access through a side branch of the femoral artery.12-14 This method requires older, larger mice and more surgical skill to implement the endoluminal access through the smaller artery. It also requires the ligation of the muscular branch of the femoral artery following the procedure. The second method we describe uses an arteriotomy in the branch point of the main and side branch and thereby allows for a larger access to the artery for performing wire injury. In this method, the arteriotomy is closed using controlled local cauterization that leaves both branches with blood flow following the procedure. The conventional method is applicable to mice of at least 20 weeks of age while the alternative method can be used in mice of at least 15 weeks of age. In both methods, the wire creates arterial stretch and abrasion leading to injury and endothelial denudation. Following either procedure a perivascular drug delivery patch can be implanted that allows the delivery of compounds to alter the response to injury. The use of the drug delivery patch allows mice to be used as a test bed for new compounds to inhibit restenosis through perivascular therapies.15,16

<table><tbody><tr><td>Straight spring wire, 0.15&amp;rdquo; diameter</td><td>Cook</td><td>G02426</td><td></td></tr><tr><td>High Temperature cautery</td><td>Bovie Medical Corp.</td><td>HIT1</td><td></td></tr><tr><td>High-temperature fine tip for cautery</td><td>Bovie Medical Corp.</td><td>H101</td><td></td></tr><tr><td>Micro-scissors</td><td>Fine Science Tools</td><td>15000-13</td><td>For performance of arteriotomy</td></tr><tr><td>Angled fine-tipped forceps</td><td>Fine Science Tools</td><td>11251-35</td><td>For blunt dissection of vascular bundle</td></tr><tr><td>Angled forceps</td><td>Roboz</td><td>RS-5069</td><td>For clearing tissues</td></tr><tr><td>Surgical scissors</td><td>Roboz</td><td>RS-5840</td><td>For cutting skin</td></tr><tr><td>Retractor</td><td>Fine Science Tools</td><td>18200-10</td><td></td></tr><tr><td>Retractor wire</td><td>Fine Science Tools</td><td>18200-05</td><td>Attached to retractor</td></tr><tr><td>Base plate</td><td>Fine Science Tools</td><td>18200-03</td><td>For use with retractor</td></tr><tr><td>Magnetic retractor fixator</td><td>Fine Science Tools</td><td>18200-01</td><td></td></tr><tr><td>Needle Holder</td><td>Roboz</td><td>RS-7822</td><td></td></tr><tr><td>Hemostatic forceps</td><td>Biomedical Research Instruments, Inc.</td><td>34-1000</td><td></td></tr><tr><td>Dissecting microscope</td><td>Meiji Techno</td><td>EMZ-5TR</td><td></td></tr><tr><td>Microscope light source</td><td>Meiji Techno</td><td>FT191</td><td></td></tr><tr><td>Warm water recirculator</td><td>Gaymar</td><td>TP-500</td><td>For maintaining mouse body temperature</td></tr><tr><td>Reusable heating pad</td><td>Gaymar</td><td>TP-R 22G</td><td>For maintaining mouse body temperature</td></tr><tr><td>Lidocaine</td><td>Various</td><td></td><td></td></tr><tr><td>4.0 Vicryl suture with half circle needle</td><td>Ethicon</td><td>J494G</td><td>For post-surgical wound closure</td></tr><tr><td>Sterile cotton-tipped applicators</td><td>Puritan</td><td>25-806-2WC</td><td>For application of depilatory cream and absorbing fluids</td></tr><tr><td>Depilatory cream</td><td>Nair</td><td></td><td></td></tr><tr><td>Isoflurane</td><td>Various</td><td></td><td></td></tr><tr><td>Betadine</td><td>Various</td><td></td><td></td></tr><tr><td>70% ethanol</td><td>Various</td><td></td><td></td></tr><tr><td>6.0 braided silk suture</td><td>Teleflex Medical</td><td>4-S</td><td>For isolation of femoral artery during surgery</td></tr><tr><td>0.9% sodium chloride</td><td>Various</td><td></td><td>For irrigating tissues</td></tr><tr><td>Gel eye lubricant</td><td>Various</td><td></td><td></td></tr><tr><td>Glass Petri dish</td><td>Pyrex</td><td>3160-60</td><td>For femoral artery harvest</td></tr><tr><td>10% buffered formalin</td><td>Various</td><td></td><td>For fixation of femoral artery</td></tr><tr><td>70% ethanol</td><td>Various</td><td></td><td>For fixation of femoral artery</td></tr><tr><td>Bouin&#039;s fluid</td><td>Electron Microscopy Sciences</td><td></td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Alcian blue, 1%</td><td>Electron Microscopy Sciences</td><td>26385-01</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Alkaline alcohol</td><td>Electron Microscopy Sciences</td><td>26385-02</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Orcein, 0.2%</td><td>Electron Microscopy Sciences</td><td>26385-03</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Hematoxylin alcoholic, 5%</td><td>Electron Microscopy Sciences</td><td>26385-04</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Ferric chloride, 10%</td><td>Electron Microscopy Sciences</td><td>26385-05</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Lugol&#039;s Iodine</td><td>Electron Microscopy Sciences</td><td>26385-06</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Woodstain scarlet-acid fuchsin working solution</td><td>Electron Microscopy Sciences</td><td>26385-07</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Acetic acid, 0.5%</td><td>Electron Microscopy Sciences</td><td>Various</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Phosphotungstic acid, 5%</td><td>Electron Microscopy Sciences</td><td>26385-09</td><td>For Movat&#039;s Pentachrome staining</td></tr><tr><td>Alcoholic saffron, 6%</td><td>Electron Microscopy Sciences</td><td>26385-10</td><td>For Movat&#039;s Pentachrome staining</td></tr></tbody></table>

murine model of femoral artery wire injury with implantation of a perivascular drug delivery patch

Percutaneous interventions including balloon angioplasty and stenting have been used to restore blood flow in vessels with occlusive vascular disease. While these therapies lead to the rapid restoration of blood flow, these technologies remain limited by restenosis in the case of bare metal stents and angioplasty, or reduced healing and possibly enhanced risk of thrombosis in the case of drug eluting stents. A key pathophysiological mechanism in the formation of restenosis is intimal hyperplasia caused by the activation of vascular smooth muscle cells and inflammation due to arterial stretch and injury. Surgeries that induce arterial injury in genetically modified mice are useful for the mechanistic study of the vascular response to injury but are often technically challenging to perform in mouse models due to the their small size and lack of appropriate sized devices. We describe two approaches for a surgical technique that induces endothelial denudation and arterial stretch in the femoral artery of mice to produce robust neointimal hyperplasia. The first approach creates an arteriotomy in the muscular branch of the femoral artery to obtain vascular access. Following wire injury this arterial branch is ligated to close the arteriotomy. A second approach creates an arteriotomy in the main femoral artery that is later closed through localized cautery. This method allows for vascular access through a larger vessel and, consequently, provides a less technically demanding procedure that can be used in smaller mice. Following either method of arterial injury, a degradable drug delivery patch can be placed over or around the injured artery to deliver therapeutic agents.

Após lesão fio, hiperplasia neointimal desenvolve ao longo do tempo e normalmente é examinado após 14 a 28 dias. As técnicas descritas neste trabalho levam à geração robusta de hiperplasia da íntima em camundongos como mostra os resultados histológicos na Figura 3. Uma artéria femoral ileso irá demonstrar lamelas elásticas intactas e uma espessura normal e circunferência. Uma artéria femoral ferido irá mostrar hiperplasia da íntima, degradada lamelas elásticas e demonstrar reendotelização em momentos posteriores. Re-Endotelização é tipicamente completa em cerca de 21 dias, mas isso depende da estirpe dos ratos usados ​​fundo e pode ser avaliada através de imunomarcação para marcadores endoteliais em secções ou, de preferência, medidos em en preparações cara usando corante azul de Evan, microscopia eletrônica de varredura ou imunológica com microscopia confocal em en preparações face da artéria 17,18. Para a quantificação da hiperplasia da íntima-loé melhor para medir a área íntima ou relação íntima-to-media em três locais ao longo da artéria lesionada para explicar as possíveis variações ao longo do comprimento da região lesada da artéria. <img alt="Figura 1" src="/files/ftp_upload/52403/52403fig1highres.jpg" /> Figura 1: Fotografias dos passos críticos dos dois métodos de lesão de arame na artéria femoral Uma comparação dos passos para o método de ligação (superior) para o método cautério (inferior) para a realização de lesão de arame.. No método de ligação, as duas suturas de fixação do ramo muscular são pré-amarrado para que eles possam ser apertados para ligar o ramo muscular. Quanto mais distal das duas suturas ramo muscular é apertada. A inserção arteriotomia e fio são realizadas no ramo muscular. Após a lesão é realizada, a sutura restante no ramo muscular é apertada e aparado. No método de cautério, apenas um suture é enrolado sob o ramo muscular. A arteriotomia e inserção do fio são executadas ao ponto de ramificação do ramo muscular da artéria femoral. Após a lesão é realizada, a incisão é cauterizado sem a ligadura ou a artéria femoral ou ramo muscular. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/52403/52403fig1large.jpg" target="_blank">Por favor, clique aqui para ver uma versão maior desta figura.</a> <img alt="Figura 2" src="/files/ftp_upload/52403/52403fig2highres.jpg" /> Figura 2: fotografias ampliação maior dos passos críticos das duas técnicas de lesão fio comparação Close-up de etapas para o método de ligação (em cima) com o método de cautério (parte inferior).. A localização do arteriotomy é demarcada com a linha tracejada. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/52403/52403fig2large.jpg" target="_blank">Por favor, clique aqui para ver uma versão maior desta</a>figura. <img alt="Figura 3" src="/files/ftp_upload/52403/52403fig3highres.jpg" /> Figura 3:. Resultados histológicos representativos de lesão fio 14 dias após o procedimento histológica das seções artérias foram coradas com Hematoxilina e Eosina (parte superior) e coloração pentachrome de Movat (parte inferior). Marcado na imagem são o lúmen (L), íntima (I) e da lâmina elástica (EL).

Watch this Scientific Journal Video about Murine Model of Femoral Artery Wire Injury with Implantation of a Perivascular Drug Delivery Patch at JoVE.com

Murine Model of Femoral Artery Wire Injury with Implantation of a Perivascular Drug Delivery Patch

We describe a surgical technique that produces wire injury in the femoral artery of mice to induce neointimal hyperplasia to serve as a model testing system for the perivascular delivery of therapeutic compounds for the inhibition of restenosis.

Modelo murino de artéria femoral Injury fio com a implantação de uma droga patch Entrega perivascular

Percutaneous interventions including balloon angioplasty and stenting have been used to restore blood flow in vessels with occlusive vascular disease. ...

murine-model-femoral-artery-wire-injury-with-implantation

Nanyang Technological University

Research

JoVE Journal

Medicine

17.9K visualizações.  University of Texas at Austin. We describe a surgical technique that produces wire injury in the femoral artery of mice to induce neointimal hyperplasia to serve as a model testing system for the perivascular delivery of therapeutic compounds for the inhibition of restenosis. 

Vídeo: Murine Model of Femoral Artery Wire Injury with Implantation of a Perivascular Drug Delivery Patch

Programming Stem Cells for Therapeutic Angiogenesis Using Biodegradable Polymeric Nanoparticles

Controlled vascular growth is critical for successful tissue regeneration and wound healing, as well as for treating ischemic diseases such as stroke, heart attack or peripheral arterial diseases. Direct delivery of angiogenic growth factors has the potential to stimulate new blood vessel growth, but is often associated with limitations such as lack of targeting and short half-life in vivo. Gene therapy offers an alternative approach by delivering genes encoding angiogenic factors, but often requires using virus, and is limited by safety concerns. Here we describe a recently developed strategy for stimulating vascular growth by programming stem cells to overexpress angiogenic factors in situ using biodegradable polymeric nanoparticles. Specifically our strategy utilized stem cells as delivery vehicles by taking advantage of their ability to migrate toward ischemic tissues in vivo. Using the optimized polymeric vectors, adipose-derived stem cells were modified to overexpress an angiogenic gene encoding vascular endothelial growth factor (VEGF). We described the processes for polymer synthesis, nanoparticle formation, transfecting stem cells in vitro, as well as methods for validating the efficacy of VEGF-expressing stem cells for promoting angiogenesis in a murine hindlimb ischemia model.

We describe the method of programming stem cells to overexpress therapeutic factors for angiogenesis using biodegradable polymeric nanoparticles. Processes described include polymer synthesis, transfecting adipose-derived stem cells in vitro, and validating the efficacy of programmed stem cells to promote angiogenesis in a murine hindlimb ischemia model.

Células-tronco de programação para Therapeutic angiogênese Usando nanopartículas poliméricas biodegradáveis

Controlled vascular growth is critical for successful tissue regeneration and wound healing, as well as for treating ischemic diseases such as stroke, ...

Bioengenharia

Osmotic Drug Delivery to Ischemic Hindlimbs and Perfusion of Vasculature with Microfil for Micro-Computed Tomography Imaging

Preclinical research in animal models of peripheral arterial disease plays a vital role in testing the efficacy of therapeutic agents designed to stimulate microcirculation. The choice of delivery method for these agents is important because the route of administration profoundly affects the bioactivity and efficacy of these agents1,2. In this article, we demonstrate how to locally administer a substance in ischemic hindlimbs by using a catheterized osmotic pump. This pump can deliver a fixed volume of aqueous solution continuously for an allotted period of time. We also present our mouse model of unilateral hindlimb ischemia induced by ligation of the common femoral artery proximal to the origin of profunda femoris and epigastrica arteries in the left hindlimb. Lastly, we describe the in vivo cannulation and ligation of the infrarenal abdominal aorta and perfusion of the hindlimb vasculature with Microfil, a silicone radiopaque casting agent. Microfil can perfuse and fill the entire vascular bed (arterial and venous), and because we have ligated the major vascular conduit for exit, the agent can be retained in the vasculature for future ex vivo imaging with the use of small specimen micro-CT3.

We show here the in vivo insertion of an osmotic pump for constant local drug delivery and the creation of hindlimb ischemia in a mouse model. Moreover, the hindlimb vasculature is perfused with Microfil, a silicone radiopaque agent, to prepare for micro-computed tomography (micro-CT) imaging.

Osmótica Drug Delivery para hindlimbs isquêmicos e perfusão da vasculatura com Microfil para Micro-tomografia computadorizada

Preclinical research in animal models of peripheral arterial disease plays a vital role in testing the efficacy of therapeutic agents designed to ...

Medicina

A Radio-telemetric System to Monitor Cardiovascular Function in Rats with Spinal Cord Transection and Embryonic Neural Stem Cell Grafts

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter connected to a radio transmitter into the femoral artery of rats that underwent a T4 spinal cord transection with or without grafting of embryonic brainstem-derived neural stem cells expressing green fluorescent protein. Compared to other methods such as cannula insertion or tail-cuff, telemetry is advantageous to continuously monitor blood pressure and heart rate in freely moving animals. It is also capable of long term multiple data acquisitions. In spinal cord injured rats, basal cardiovascular data under unrestrained condition and autonomic dysreflexia in response to colorectal distension were successfully recorded. In addition, cardiovascular parameters before and after SCI can be compared in the same rat if a transmitter is implanted before a spinal cord transection. One limitation of the described telemetry procedure is that implantation in the femoral artery may influence the blood supply to the ipsilateral hindlimb.

We present a protocol for using a radio-telemetric system to record cardiovascular parameters in T4 spinal cord transected rats eight weeks after embryonic brainstem neural stem cell grafting into the lesion site. Telemetry is an advanced technique to accurately evaluate cardiovascular function in conscious freely moving spinal cord injured rats.

Um sistema de rádio-telemetria para monitorar a função cardiovascular em ratos com Medula Espinhal transecção e Embryonic Stem Neural enxertos de células-

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter ...

A Murine Model of Arterial Restenosis: Technical Aspects of Femoral Wire Injury

Cardiovascular disease caused by atherosclerosis is the leading cause of death in the developed world. Narrowing of the vessel lumen, due to atherosclerotic plaque development or the rupturing of established plaques, interrupts normal blood flow leading to various morbidities such as myocardial infarction and stroke. In the clinic endovascular procedures such as angioplasty are commonly performed to reopen the lumen. However, these treatments inevitably damage the vessel wall as well as the vascular endothelium, triggering an excessive healing response and the development of a neointimal plaque that extends into the lumen causing vessel restenosis (re-narrowing). Restenosis remains a major cause of failure of endovascular treatments for atherosclerosis. Thus, preclinical animal models of restenosis are vitally important for investigating the pathophysiological mechanisms as well as translational approaches to vascular interventions. Among several murine experimental models, femoral artery wire injury is widely accepted as the most suitable for studies of post-angioplasty restenosis because it closely resembles the angioplasty procedure that injures both endothelium and vessel wall. However, many researchers have difficulty utilizing this model due to its high degree of technical difficulty. This is primarily because a metal wire needs to be inserted into the femoral artery, which is approximately three times thinner than the wire, to generate sufficient injury to induce prominent neointima. Here, we describe the essential surgical details to effectively overcome the major technical difficulties of this model. By following the presented procedures, performing the mouse femoral artery wire injury becomes easier. Once familiarized, the whole procedure can be completed within 20 min.

The mouse femoral artery wire injury model of restenosis is technically challenging. In this protocol we show the key technical details essential for successfully performing wire injury to induce consistent&#160;neointima for studies of restenosis.

Um modelo murino de Arterial Restenosis: Aspectos Técnicos do Femoral Injury Fio

Cardiovascular disease caused by atherosclerosis is the leading cause of death in the developed world. Narrowing of the vessel lumen, due to ...

A Hydrogel Construct and Fibrin-based Glue Approach to Deliver Therapeutics in a Murine Myocardial Infarction Model.

The murine MI model is widely recognized in the field of cardiovascular disease, and has consistently been used as a first step to test the efficacy of treatments in vivo1. The traditional, established protocol has been further fine-tuned to minimize the damage to the animal. Notably, the pectoral muscle layers are teased away rather than simply cut, and the thoracotomy is approached intercostally as opposed to breaking the ribs in a sternotomy, preserving the integrity of the ribcage. With these changes, the overall stress on the animal is decreased. 
Stem cell therapies aimed to alleviate the damage caused by MIs have shown promise over the years for their pro-angiogenic and anti-apoptotic benefits. Current approaches of delivering cells to the heart surface typically involve the injection of the cells either near the damaged site, within a coronary artery, or into the peripheral blood stream2-4. While the cells have proven to home to the damaged myocardium, functionality is limited by their poor engraftment at the site of injury, resulting in diffusion into the blood stream5. This manuscript highlights a procedure that overcomes this obstacle with the use of a cell-encapsulated hydrogel patch. The patch is fabricated prior to the surgical procedure and is placed on the injured myocardium immediately following the occlusion of the left coronary artery. To adhere the patch in place, biocompatible external fibrin glue is placed directly on top of the patch, allowing for it to dry to both the patch and the heart surface. This approach provides a novel adhesion method for the application of a delicate cell-encapsulating therapeutic construct.

This protocol aims to alleviate the limitation of poor cell engraftment for stem cell treatment of myocardial infarctions through the use of a hydrogel system and a fibrin-based glue. With this approach, cell-to-tissue contact post-infarction can be maintained, increasing the therapeutic potential of beneficial agents at the site of injury.

Um hidrogel Construir e fibrina à base de cola Approach to Deliver Therapeutics em um Infarto do Miocárdio modelo murino.

The murine MI model is widely recognized in the field of cardiovascular disease, and has consistently been used as a first step to test the efficacy of ...

Induction of Accelerated Atherosclerosis in Mice: The "Wire-Injury" Model

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. Moreover, by rupture of the defective vascular wall, atherosclerosis induces occlusive thrombus formation, which represents the main cause of myocardial infarction or stroke and the most frequent cause of death. Despite the advances in the cardiovascular field, many questions remain unanswered, and additional basic research is essential to improve our understanding of the molecular mechanisms during atherosclerosis and its effects. Due to limited clinical studies, there is a need for representative animal models recreating atherosclerotic conditions such as neointima formation after stent implantation, balloon angioplasty, or endarterectomy. Since the mouse presents many advantages and is the most frequently used model for studying molecular processes, the current study proposes an invasive procedure of endothelial denudation, also known as the wire-injury model, which is representative of the human condition of neointima formation in arteries after revascularization procedures.

This study describes an invasive procedure for the induction of accelerated atherosclerosis in mice. In comparison to other methods using electric- or cryo-induced injury, mechanical-induced injury mimics the human condition of restenosis after revascularization therapies and is ideal for the study of the molecular mechanisms involved.

Indução de Aterosclerose Acelerada em Camundongos: O Modelo de "Lesão por Fio"

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. ...

Patch Angioplasty in the Rat Aorta or Inferior Vena Cava

Pericardial patches are commonly used in vascular surgery to close vessels. To facilitate studies of the neointimal hyperplasia that forms on the patch, we developed a rat model of patch angioplasty that can be used in either a vein or an artery, creating a patch venoplasty or a patch arterioplasty, respectively. Technical aspects of this model are discussed. The infra-renal IVC or aorta are dissected and then clamped proximally and distally. A 3 mm venotomy or arteriotomy is performed in the infrarenal inferior vena cava or aorta of 6 to 8 week-old Wistar rats. A bovine pericardial patch (3 mm x 1.5 mm x 0.6 mm) is then used to close the site using a 10-0 nylon suture. Compared to arterial patches, venous patches show increased neointimal thickness on postoperative day 7. This novel model of pericardial patch angioplasty can be used to examine neointimal hyperplasia on vascular biomaterials, as well as to compare the differences between the arterial and venous environments.

We have established a model of pericardial patch angioplasty that can be used in either small-diameter veins or arteries. This model can be used to compare venous and arterial neointimal hyperplasia formation.

Remendar Angioplastia na Rat aorta ou veia cava inferior

Pericardial patches are commonly used in vascular surgery to close vessels. To facilitate studies of the neointimal hyperplasia that forms on the patch, ...

Transplantation of a 3D Bioprinted Patch in a Murine Model of Myocardial Infarction

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ligation is a challenging procedure and has a high mortality rate due to its nature. We developed a method to consistently transplant bioprinted patches of cells and hydrogels onto the epicardium of an infarcted mouse heart to test their regenerative properties in a robust and feasible way. First, a deeply anesthetized mouse is carefully intubated and ventilated. Following left lateral thoracotomy (surgical opening of the chest), the exposed LAD is permanently ligated and the bioprinted patch transplanted onto the epicardium. The mouse quickly recovers from the procedure after chest closure. The advantages of this robust and quick approach include a predicted 28-day mortality rate of up to 30% (lower than the 44% reported by other studies using a similar model of permanent LAD ligation in mice). Moreover, the approach described in this protocol is versatile and could be adapted to test bioprinted patches using different cell types or hydrogels where high numbers of animals are needed to optimally power studies. Overall, we present this as an advantageous approach which may change preclinical testing in future studies for the field of cardiac regeneration and tissue engineering.

This protocol aims to transplant a 3D bioprinted patch onto the epicardium of infarcted mice modeling heart failure. It includes details regarding anesthesia, the surgical chest opening, permanent ligation of the left anterior descending (LAD) coronary artery and application of a bioprinted patch onto the infarcted area of the heart.

Transplante de um Patch Bioimpresso 3D em um modelo murino de infarto do miocárdio

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ...

Implantation of Tissue-Engineered Vascular Graft in Mouse Carotid Artery via Cuff Technique

The development of small-diameter vascular grafts has been a global endeavor, with numerous research groups contributing to this field. Animal experimentation plays a pivotal role in assessing the efficacy and safety of vascular grafts, particularly in the absence of clinical applications. Compared to alternative animal models, the mouse implantation model offers several advantages, including a well-defined genetic background, a mature method for disease model construction, and a straightforward surgical procedure. Based on these advantages, the present study devised a simple cuff technique for the implantation of tissue-engineered vascular grafts in the mouse carotid artery. This technique began with the fabrication of polycaprolactone (PCL) small-diameter vascular grafts via electrostatic spinning, followed by the seeding of macrophages onto the grafts through perfusion adsorption. Subsequently,&#160;the cellularized tissue-engineered vascular grafts were transplanted into the mouse carotid artery using the cuff technique to evaluate patency and regenerative capability. After 30 days of in vivo implantation, vascular patency was found to be satisfactory, with evidence of neo-tissue regeneration and the formation of an endothelial layer within the lumen of the grafts. All data were analyzed using statistical and graphing software. This study successfully established a mouse carotid artery implantation model that can be used to explore the cellular sources of vascular regeneration and the mechanisms of action of active substances. Furthermore, it provides theoretical support for the development of novel small-diameter vascular grafts.

Here, a protocol is presented for the implantation of a tissue-engineered vascular graft into the mouse carotid artery using the cuff technique, providing a suitable animal model for investigating vascular tissue regeneration mechanisms.

Implante de enxerto vascular de engenharia de tecidos na artéria carótida de camundongo via técnica de manguito

The development of small-diameter vascular grafts has been a global endeavor, with numerous research groups contributing to this field. Animal ...

Multiphoton Intravital Imaging for Monitoring Leukocyte Recruitment during Arteriogenesis in a Murine Hindlimb Model

Arteriogenesis strongly depends on leukocyte and platelet recruitment to the perivascular space of growing collateral vessels. The standard approach for analyzing collateral arteries and leukocytes in arteriogenesis is ex vivo (immuno-) histological methodology. However, this technique does not allow the measurement of dynamic processes such as blood flow, shear stress, cell-cell interactions, and particle velocity. This paper presents a protocol to monitor in vivo processes in growing collateral arteries during arteriogenesis utilizing intravital imaging. The method described here is a reliable tool for dynamics measurement and offers a high-contrast analysis with minimal photo-cytotoxicity, provided by multiphoton excitation microscopy. Prior to analyzing growing collateral arteries, arteriogenesis was induced in the adductor muscle of mice by unilateral ligation of the femoral artery.
After the ligation, the preexisting collateral arteries started to grow due to increased shear stress. Twenty-four hours after surgery, the skin and subcutaneous fat above the collateral arteries were removed, constructing a pocket for further analyses. To visualize blood flow and immune cells during in vivo imaging, CD41-fluorescein isothiocyanate (FITC) (platelets) and CD45-phycoerythrin (PE) (leukocytes) antibodies were injected intravenously (i.v.) via a catheter placed in the tail vein of a mouse. This article introduces intravital multiphoton imaging as an alternative or in vivo complementation to the commonly used static ex vivo (immuno-) histological analyses to study processes relevant for arteriogenesis. In summary, this paper describes a novel and dynamic in vivo method to investigate immune cell trafficking, blood flow, and shear stress in a hindlimb model of arteriogenesis, which enhances evaluation possibilities notably.

The recruitment of leukocytes and platelets constitutes an essential component necessary for the effective growth of collateral arteries during arteriogenesis. Multiphoton microscopy is an efficient tool for tracking cell dynamics with high spatio-temporal resolution in vivo and less photo-toxicity to study leukocyte recruitment and extravasation during arteriogenesis.

Imagem Intravital Multifóton para Monitoramento do Recrutamento de Leucócitos durante a Arteriogênese em Modelo de Membro Posterior Murino

Arteriogenesis strongly depends on leukocyte and platelet recruitment to the perivascular space of growing collateral vessels. The standard approach for ...