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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Utilização de fios de sutura com células tronco mesenquimais de tecido adiposo aderidas : avaliação da cicatrização e recuperação de fístulas enterocutâneas em ratos / Attachment capacity of adipocyte tissue mesenchymal stem cells in suture filaments : new tool for the treatment of enterocutaneous fistula

Volpe, Bruno Bosch, 1988- 23 August 2018 (has links)
Orientadores: Ângela Cristina Malheiros Luzo, Joaquim Murray Bustorff Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-23T07:41:35Z (GMT). No. of bitstreams: 1 Volpe_BrunoBosch_M.pdf: 3151194 bytes, checksum: afd54e9f5fdcdd55a24ddfa4b90d02a7 (MD5) Previous issue date: 2013 / Resumo: As fístulas enterocutâneas (FE) são de difícil cicatrização e seu tratamento cirúrgico frequentemente falha, fazendo com que a fistula volte a abrir. Estudos recentes têm demonstrado que a terapia celular pode ser uma nova forma de tratamento nesta área. As células tronco mesenquimais (MSCs) são capazes de se auto- renovar tem alta capacidade proliferativa, podendo se diferenciar em várias linhagens celulares. Ainda apresentam capacidade imunomodulatória. A medula óssea, o sangue de cordão umbilical e o tecido adiposo são as principais fontes de MSCs. O tecido adiposo (TA) é de fácil acesso, sendo que o procedimento de lipoaspiração é um procedimento comum. O tratamento de fístulas enterocutâneas com AT-MSCs já foi testado algumas vezes, porém a fístula em sua grande maioria não se fecha totalmente. O objetivo deste estudo foi analisar o potencial terapêutico das MSCs aderidas a fios de sutura no intuito de melhorar a cicatrização e recuperação no tratamento de FE. O TA foi obtido através do procedimento de lipoaspiração. O TA foi submetido ao processo de digestão com colagenase. As células ficaram em meio de cultura DMEM com baixa glicose e com SFB durante 3 dias. Quando atingiram 80% de confluência, as células aderentes foram tratadas com tripsina e ressuspendidas com o meio citado acima. Na 4ª passagem essas células foram caracterizadas com citometria de fluxo, microscopia confocal e diferenciadas nas três linhagens mesodérmicas para confirmação que realmente são MSCs. Após, a confirmação de que as células eram realmente células tronco mesenquimais, elas foram aderidas em fios de sutura de poliglactina (4-0 Poly Vicryl / Poliglactina 910). Foram gotejadas 106 MSCs em cima de cada fio de sutura e logo em seguida foi adicionada a cola de fibrina (20uL Fibrinogênio, 30uL Trombina e 10uL Cloreto de Cálcio) para ajudar na fixação das células. Os fios de sutura com MSCs aderidas ficaram em meio de cultura durante 24 horas para proliferação celular. As amostras foram analisadas por microscopia confocal de imnunofluorescência e eletrônica de varredura. O experimento animal utilizou ratos Wistar com 10 semanas de vida que foram distribuídos em três grupos: Grupo Controle (GC) que incluiu 5 animais onde a formação da fístula foi através de cirurgia sem nenhum tipo de suporte. Grupo Injeção (GI) que incluiu 8 animais que receberam uma injeção de 106 AT-MSCs ao redor do local de formação da fístula. Grupo Sutura (GS) que incluiu 9 animais que receberam sutura de 4-0 Vicryl (poliglactina) com 106 AT-MSCs aderidas com a ajuda de cola de fibrina. Após a exposição do ceco foi realizada enterotomia de 5mm, sendo então realizada a sutura da abertura a abertura da parede abdominal (superfície interna da pele) com 4 pontos separados com 4-0 Vicryl - Poly J-304 Polyglactin 910. No grupo GS, o fio para confecção da fístula, como descrita acima, continha 106 AT-MSCs aderidas. As fístulas foram fotografadas no dia da cirurgia e no 3°, 6°, 9°, 12°, 15°, 17°, 19° e 21° dias, onde foram anestesiados e sacrificados. O tamanho da área da fístula foi mensurado através do software ImageJ. Foram utilizados dois métodos estatísticos para analisar os dados do modelo animal. O primeiro método foi o Two-way Anova, fazendo a análise comparativa da cicatrização entre os três grupos, e o segundo o One-way analysis of variance, fazendo a análise comparativa da cicatrização entre os três grupos nos dias D0, D12 e D21. As microscopias confocal de imunofluorescência e eletrônica de varredura demonstraram a presença de AT-MSCs aderidas aos fios de sutura. No experimento animal mostrou que a média de redução do tamanho da área da fístula no 21º dia foi de 46,54% no GC, 71,80% no GI e 90,34% no GS (p<0,05), demonstrando que as MSCs foram eficazes na cicatrização das fístulas enterocutâneas tanto no grupo que recebeu a injeção de células quanto no grupo que utilizou as células aderidas ao fio de sutura. As MSCs foram capazes de se fixarem nos fios de sutura. Quando as fístulas enterocutâneas receberam a sutura com MSCs aderidas, elas mostraram uma melhor recuperação e cicatrização da fístula. AT-MSCs aderidas a fios de sutura pode ser uma nova e efetiva forma no tratamento de fístulas enterocutâneas / Abstract: Enterocutaneous fistulas (EF) are difficult to resolve and surgical failure is frequent. Cell therapy could be a new approach in this area. Mesenchymal stem cells (MSCs) have high proliferative capacity, can differentiate into several lineages and have immunomodulatory capacity. Adipocyte tissue (AT) is an easy source of them. Enterocutaneous fistula (EF) treatment with MSCs was yet performed but sometimes, the fistula did not close completely. The aim of this study is to analyze if AT-MSCs could attached in the suture filament in order to be used for EF treatment. AT obtained from lipoaspirate procedure was submitted to collagenase digestion. Cells were cultured in DMEM low glucose medium, with FBS during 3 days. At the 4ª passages, cells were characterized by flow cytometry, confocal microscopy, differentiated to mesodermal lineages to confirm MSCs and telomerase enzyme activity and karyotype analysis. The experiments were performed with polyester suture filament. MSCs, 106 cells, were fixed in the suture filament by adding fibrin glue.Filaments was led in the medium described above during 3 days. Samples were analyzed by confocal and scanning electron microscopy. The animal experiments were performed on 10 weeks old male Wistar rats divided into 3 groups. Control Group (CG): 5 animals undergoing fistula formation alone. Injection Group (IG):8 animals receiving 106 AT-MSCs injected around the suture line. Suture Filament Group (SG): 9 animals in which suture were performed using 4-0 Vicryl with 106 MSCs attached in the filament with fibrin glue. The cecum was accessed through a standard 7mm stab incision on the lower left side of the abdomen. Upon exposure, a 5mm enterotomy was performed and sutured to the abdominal wall in order to produce the fistula. To ensure normal closure of the fistula the opening in the cecum wall was fixed to the internal surface of the skin, without maturation, using four separate 4-0 Vicryl stitches (Poly J-304 Polyglactin 910 Ethicon). The fistulas were photographed on the day of operation and on the 3°, 6°, 9°, 12°, 15°, 17°, 19° and 21° day, in which they were anesthetized and sacrificed. Measure of the size of the fistula was performed using ImageJ software. Statistic comparison between the groups was performed by ANOVA. Confocal and scanning electronic microscopy results demonstrated that the cells were able to attach to the suture filaments. Animal experiments showed that the average size reduction of the fistula area at 21th day was: control group, 46.54%; injected group 71.80% and sutured group 90.34% (p<0,05). MSCs were able to attach to the suture filaments. When the fistulas were sutured with filaments containing MSCs they showed better recovery and healing than the injected and control group. Adipocyte tissue MSCs adhered to suture filament might be a new and effective approach for enterocutaneus fistulas treatment / Mestrado / Fisiopatologia Cirúrgica / Mestre em Ciências
2

Thérapie cellulaire en endoscopie interventionnelle digestive / Cellular therapy in digestive interventional endoscopy

Rahmi, Gabriel 27 November 2015 (has links)
Le développement récent de l’endoscopie interventionnelle digestive nous a conduit à prendre en charge deux types de pathologies préoccupantes. Il s’agit d’une part des fistules digestives souvent responsables d’une morbi-mortalité élevée et d’autre part des sténoses œsophagiennes après résection tumorale endoscopique étendue. Dans ces deux situations, des phénomènes inflammatoires chroniques conduisent soit à l’absence de fermeture de la fistule soit à une fibrose importante responsable de sténose de l’œsophage. La thérapie cellulaire a déjà été utilisée pour diminuer ces phénomènes inflammatoires et entrainer une cicatrisation. La thérapie tissulaire par cellules souches organisées en construction 3D représente un avantage important en permettant de cibler le site d’action par dépôt direct du feuillet cellularisé. Notre objectif était d’évaluer l’effet thérapeutique de ces nouveaux outils pour fermer les fistules digestives et pour prévenir la survenue des sténoses œsophagiennes. La première étape a consisté a évaluer l’efficacité du traitement par des cellules souches mésenchymateuses provenant de moelle osseuse humaine, marquées puis organisées en doubles feuillets, dans un modèle de fistule entéro-cutanée post-chirurgicale chez la souris nude. L’évaluation clinique et en imagerie (IRM et microscopie confocale) a montré une meilleure cicatrisation avec une augmentation de la microvascularisation et une accélération de la fermeture de la fistule chez les souris greffées. Les effets observés semblent liés à une augmentation précoce de la synthèse des facteurs de réparation (EGF et le VEGF) et des cytokines anti-inflammatoires (TGF-ß2 et IL-10). Après avoir développé un modèle inédit de fistule oeso-cutanée chez le porc grâce à la mise en place par voie endoscopique et chirurgicale de prothèses plastiques entre la lumière œsophagienne et la peau, nous avons évalué l’efficacité thérapeutique d’un gel contenant des vésicules extracellulaires issues de cellules souches isolées du tissu adipeux de porc. Ce gel injecté dans la fistule par voie endoscopique a permis la fermeture des fistules. Enfin, la troisième partie de notre travail a consisté à évaluer l’efficacité de la greffe allogénique de doubles feuillets de cellules souches mésenchymateuses pour prévenir la survenue des sténoses œsophagiennes dans un modèle porcin après dissection sous muqueuse étendue. Il existait une réduction significative du taux de sténose œsophagienne cicatricielle dans le groupe greffé avec une fibrose moins importante. En conclusion, l’effet paracrine antifibrosant des cellules souches mésenchymateuses organisées en feuillets est efficace à la fois pour fermer les fistules entéro-cutanées chez la souris et pour prévenir les sténoses œsophagiennes chez le porc. Un gel avec des vésicules extracellulaires issues des cellules souches a de la même façon un effet cicatrisant anti-inflammatoire permettant la fermeture des fistules œsophagiennes chez le porc. Ces résultats sont très encourageants et posent la question d’une évaluation future chez l’homme. / Recent developments in digestive interventional endoscopy lead us to manage two types of digestive disease. First, it is digestive fistulas associated in many cases with high morbi-mortality; and second is oesophageal stenosis after extended superficial endoscopic resection. In both situations, chronic inflammatory process resulted in delayed or no fistula healing for the first case or oesophageal stenosis due to fibrosis. Cellular therapy has proved to be successful in reducing the inflammatory process and to promote tissue healing. Tissue therapy with 3D construct stem cells represents a major advantage by allowing a direct adaptation on the right place. Our objective was to evaluate the therapeutic effect of new strategy to close the digestive fistula and to prevent oesophageal stenosis. First step was to evaluate the effect of labelled human bone marrow derived mesenchymal stem cells engraftment in the form of double cellsheet in a post-surgical fistula model in nude mice. Clinical and radiological (MRI and probe based confocal microscopy) evaluation showed a better fistula healing with higher microvascularization and a faster fistula closing in grafted mice. These effects appear to be related to an increase production of factors involved in tissue repair (EGF et le VEGF) and anti-inflammatory cytokines (TGF-ß2 et IL-10). We developed an unpublished eso-cutaneous fistula in a porcine model after plastic catheters placement by surgical and endoscopic way between the oesophageal lumen and the skin. We evaluated the therapeutic effect of a hydrogel with extracellular vesicles extracted from porcine adipose derived stem cells. The hydrogel with vesicles was injected into the fistula by endoscopy. Radiological and histological evaluation 15 days after injection showed a fistula tract closure in treated group.The third part of this work was to evaluate the effect of allograft of adipose derived stem cells 3D construct to prevent the stenosis after extended endoscopic submucosal dissection in a porcine model. There was a significant reduction of number and degree of stenosis with decrease fibrosis infiltration in the grafted group.In summary, thanks to their paracrine and antifibrotic effect, the mesenchymal stem cells organised as 3D construct allowed fistula closure in an entero-cutaneous model in mice and prevention of stenosis after extended oesophageal submucosal dissection in a porcine model. Moreover, endoscopic hydrogel and extracellular vesicles injection allowed oesophageal fistula healing in a porcine model. These promising results pose the challenge of future clinical studies.

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