Cancer is one of the major causes of mortality in developed countries. In 2020, there were more than 19.3 million new cases of tumor malignancies worldwide, with more than 10 million deaths. The high rates of cancer cases and mortality necessitate extensive research and the development of novel cancer treatments and antitumor agents. In most cases, conventional treatment strategies for tumor therapy are based on chemotherapeutic treatment, which is supplemented with radiotherapy and/or surgical resection of solid tumors [1]. The use of chemotherapy for the treatment of cancer has significant side effects, the most dangerous of which is toxicity [2] [3]. Modern methods of treating tumors focus on specific drug delivery to the tumor site, actively targeting the tumor cells, as well as the reduction of side effects. One of the most promising current approaches is based on oncolytic viruses. Antitumor properties of viruses were documented at the beginning of the 20th century when some cancer patients recovered after acute viral infections, particularly influenza [4]. Vaccinia virus (VACV) is a member of the Poxviridae family, has natural antitumor properties, and provides a good basis for generating efficient recombinant oncolytic strains. Furthermore, VACV has never been shown to integrate into the host genome [5]. VACV is likely one of the safest and well-studied viruses due to extensive research being done in molecular biology and pathophysiology to investigate its potential as a vaccine for smallpox eradication programs. It has been administered to over 200 million people worldwide. VACV antitumor therapeutic effectiveness has been established in xenograft models with a variety of tumor types for human and canine cancers. Furthermore, recombinant oncolytic VACVs expressing genes encoding light-emitting proteins are a big improvement in a treatment strategy that combines tumor-specific therapies and diagnostics. Oncolytic virus treatments are effective in xenograft cancer models in mice, however, the significant improvements found in mice do not always translate to human cancer patients. These therapies should be tested in dogs with spontaneous cancer not only to offer well translatable information regarding the possible efficiency of viral therapy for human cancers but also to improve the health of our household pets as well. Spontaneous canine tumors are starting to be regarded as an essential model of human cancers that can reproduce the tumor microenvironment and immune response of cancer patients [6]. Just as data obtained in dog experiments can improve cancer therapy for human patients, these findings can also be used to improve treatment protocols in canine patients. Hundreds of studies and dozens of reviews have been published regarding the antitumor effects of various recombinants of VACV, but information on the anticancer features of initial, genetically-unmodified “naïve” VACV is still limited. In the first studies, we compared different wild-type, non-modified strains of VACV and tested their oncolytic properties on a panel of various cancer cells derived from different organs. In addition, we also tested a protection system based on the “Trojan horse” concept - using a combination of human Adipose tissue-derived Stem Cells (hADSC) and three different wild-type single plaque purified Vaccinia virus strains: W1, L1, and T1. We showed that all tested human cell lines (FaDu, MDA MB 231, HNT-13, HNT-35, and PC-3) are permissive to L0, W0, T0, L1, W1, and L1 infection. Furthermore, we tested the cytotoxicity of VACV in different cancer cell lines (A549, PC-3, MDA-MB 231, FaDu, HNT-13, HNT-25, and HNT-35). All strains lysed the cells, which was most visible at 96 hpi. We also showed that all tested strains could efficiently infect and multiply in hADSC at a high level. In our in vivo study, we tested the therapeutic efficacy of the wild-type Vaccinia viruses L1, W1, and T1 alone or in combination with hADSC. Wild-type VACV strains were tested for their oncolytic efficiency in human lung adenocarcinoma (A549) in a xenograft model. Treatment of A549 tumors with different doses of L1 and W1 as well as with a L1/ADSC or W1/ADSC combination led to significant tumor regression compared to the PBS control. Additionally, the treatment with L1 and W1 and the combination of L1/ADSC and W1/ADSC was well tolerated by the animals. In the case of the wild-type Tian Tan strain, results were not obtained due to the high cytotoxicity of this strain. Therefore, it should be attenuated for further studies. In the second part of the current study, we investigated the oncolytic effect of C1-opt1, W1 opt1, and L3-opt1 strains based on the wild-type Copenhagen, Wyeth, and Lister vaccines with additional expression of turboFP635. Replication and cytotoxicity assays demonstrated that all 3 viruses were able to infect, replicate in and kill canine tumor cell lines STSA-1 and CT1258 in a virus dose- and time- dependent fashion. Cytotoxicity and replication assays were also performed on cultured canine Adipose-derived Mesenchymal Stem Cells (cAdMSC). The results showed that the cells were lysed much slower than the tumor cells. It suggests that these cells can harbour the virus for a long-term period, allowing the virus to spread into the body and there is enough time to reach the primary tumor or metastases before the cell carrier is destroyed. The viral replication in cAdMSC in our study was lower than in canine cancer cells (STSA-1 and CT1258) at the same MOI. After being studied in cell culture, C1 opt1 and their combination with cAdMSC (C1-opt1/cAdMSC) were used in canine STSA 1 tumor bearing nude mice. We tested the oncolytic effect of the C1-opt1 virus alone and in combination with cAdMSC in the canine STSA-1 xenograft mouse model. Altogether, our findings have shown that both C1-opt1 and cAdMSC/C1-opt1 significantly reduced tumor size or eliminated the tumor. There was no significant difference between C1-opt1 alone and cAdMSC/C1-opt1. The virus particles were mostly found within the tumor after 24 dpi, some amount of virus particles were found in the lungs of mice injected with a combination of cAdMSC/C1-opt1 but not in the group injected with virus alone (cAdMSC might get stuck in the lungs and cause virus propagation there). Taken together, this study provided a proof-of-concept that hADSC/cAdMSC can be used as a carrier system for the “Trojan horse” concept. However, it should be confirmed in another experimental model system, such as canine patients. Moreover, these findings suggest that wild-type, non-modified strains of Vaccinia virus isolates can be considered promising candidates for oncolytic virotherapy, especially in combination with mesenchymal stem cells. / Krebs wird zu einer der Hauptursachen für die Sterblichkeit in den Industrieländern. Im Jahr 2020 gab es weltweit mehr als 193 Millionen neue Fälle von tumormalen Erkrankungen mit mehr als 10 Millionen Todesfällen. Folglich erfordern die hohen Krebsfälle- und Mortalitätsraten umfangreiche Forschung und Entwicklung neuartiger Krebsbehandlungen und Antitumormittel. Konventionelle Behandlungsstrategien zur Tumortherapie basieren in den meisten Fällen auf einer chemotherapeutischen Behandlung, die durch Strahlentherapie und/oder chirurgische Resektion solider Tumoren ergänzt wird [1]. Die Verwendung von Chemotherapie zur Behandlung von Krebs hat erhebliche Nebenwirkungen, insbesondere die gefährlichste Intoxikation [2] [3]. ...

A incidência de neoplasias tem aumentado expressivamente nos últimos anos e o contínuo crescimento populacional, bem como seu envelhecimento, aumentará de forma significativa a estatística desta enfermidade nas doenças mundiais. O tratamento das neoplasias geralmente consiste do uso singular ou combinado entre a quimioterapia, cirurgia e radioterapia dependendo da etiologia do tumor. Nos casos onde a radioterapia é empregada, além dos efeitos terapêuticos da radiação, podem ocorrer complicações específicas e, na pele, estas complicações podem se apresentar com uma expressão clínica que varia desde o eritema cutâneo até a radionecrose, sendo este ultimo o efeito adverso com maior gravidade. O tratamento para a radionecrose consiste no desbridamento das áreas necróticas e recobrimento do leito cirúrgico. Os enxertos autólogos são mais comumente usados para este recobrimento, entretanto quando grandes áreas são afetadas, os aloenxertos são uma alternativa de tratamento oclusivo e ainda, com a adição de queratinócitos e células mesenquimais derivadas da gordura (ADSC), torna-se uma alternativa por seu conhecido papel imunomodulatório e regenerativo. Neste sentido, visando simular os efeitos adversos da radionecrose, foi criado um modelo animal de radionecrose cutânea induzida em camundongos Nude (Nu/Nu) para o desenvolvimento de terapias regenerativas baseadas em substitutos dermoepidérmicos humanos contendo, queratinócitos e ADSC, que se mostrou eficiente como tratamento oclusivo. Além disso, com este modelo animal de radionecrose estabelecido, novas possibilidades de tratamento de enfermidades envolvendo regeneração cutânea, podem ser testadas. / The neoplasms incidence has increased significantly in recent years and continued population growth and aging will increase the statistics of this illness in the world\'s diseases. The cancer treatment usually consists in individual or combined use of chemotherapy, surgery and radiotherapy depending on the etiology of the tumor. In cases where radiotherapy is used in addition to the therapeutic effects of radiation, specific complications can occur, and in the skin, these complications can be present with a clinical expression ranging from erythema to radionecrosis, and this latter being the adverse effect with greater severity. The radionecrosis treatment consists in debridementing necrotic areas and covering the surgical wounds. Autologous grafts are most commonly used for this covering, however when large areas are affected, allografts can be used for occlusive treatment and the keratinocytes and adipose derived stem cells (ADSC) addition becomes an alternative, due to the knowing for immunomodulatory and regenerative response. For that reason, aiming to simulate the radionecrosis adverse effects, an animal model of induced cutaneous radionecrosis was created, in athymic mouse Nude (Nu/Nu), for developing regenerative therapies based on human dermal-epidermal substitutes containing keratinocytes and ADSC, which proved occlusive as an efficient treatment, furthermore, having this radionecrosis animal model established, new possibilities for treatment of diseases involving dermal regeneration, can be tested.

A incidência de neoplasias tem aumentado expressivamente nos últimos anos e o contínuo crescimento populacional, bem como seu envelhecimento, aumentará de forma significativa a estatística desta enfermidade nas doenças mundiais. O tratamento das neoplasias geralmente consiste do uso singular ou combinado entre a quimioterapia, cirurgia e radioterapia dependendo da etiologia do tumor. Nos casos onde a radioterapia é empregada, além dos efeitos terapêuticos da radiação, podem ocorrer complicações específicas e, na pele, estas complicações podem se apresentar com uma expressão clínica que varia desde o eritema cutâneo até a radionecrose, sendo este ultimo o efeito adverso com maior gravidade. O tratamento para a radionecrose consiste no desbridamento das áreas necróticas e recobrimento do leito cirúrgico. Os enxertos autólogos são mais comumente usados para este recobrimento, entretanto quando grandes áreas são afetadas, os aloenxertos são uma alternativa de tratamento oclusivo e ainda, com a adição de queratinócitos e células mesenquimais derivadas da gordura (ADSC), torna-se uma alternativa por seu conhecido papel imunomodulatório e regenerativo. Neste sentido, visando simular os efeitos adversos da radionecrose, foi criado um modelo animal de radionecrose cutânea induzida em camundongos Nude (Nu/Nu) para o desenvolvimento de terapias regenerativas baseadas em substitutos dermoepidérmicos humanos contendo, queratinócitos e ADSC, que se mostrou eficiente como tratamento oclusivo. Além disso, com este modelo animal de radionecrose estabelecido, novas possibilidades de tratamento de enfermidades envolvendo regeneração cutânea, podem ser testadas. / The neoplasms incidence has increased significantly in recent years and continued population growth and aging will increase the statistics of this illness in the world\'s diseases. The cancer treatment usually consists in individual or combined use of chemotherapy, surgery and radiotherapy depending on the etiology of the tumor. In cases where radiotherapy is used in addition to the therapeutic effects of radiation, specific complications can occur, and in the skin, these complications can be present with a clinical expression ranging from erythema to radionecrosis, and this latter being the adverse effect with greater severity. The radionecrosis treatment consists in debridementing necrotic areas and covering the surgical wounds. Autologous grafts are most commonly used for this covering, however when large areas are affected, allografts can be used for occlusive treatment and the keratinocytes and adipose derived stem cells (ADSC) addition becomes an alternative, due to the knowing for immunomodulatory and regenerative response. For that reason, aiming to simulate the radionecrosis adverse effects, an animal model of induced cutaneous radionecrosis was created, in athymic mouse Nude (Nu/Nu), for developing regenerative therapies based on human dermal-epidermal substitutes containing keratinocytes and ADSC, which proved occlusive as an efficient treatment, furthermore, having this radionecrosis animal model established, new possibilities for treatment of diseases involving dermal regeneration, can be tested.

As células de pluripotência induzida (iPS) foram reportadas pela primeira vez em 2006 por Takahashi e Yamanaka e desde então vem sendo extensivamente estudadas. Por meio da técnica, células somáticas adultas adquirem comportamento muito semelhante às células tronco embrionárias, reduzindo as questões éticas relacionadas ao uso destas em pesquisas. Entretanto, os mecanismos biológicos das células iPS ainda não estão completamente elucidados. Ainda são necessárias pesquisas mais aprofundadas para garantir a segurança e eficácia de sua possível utilização em futuras terapias. Os coelhos, como modelos experimentais, são vantajosos tanto pelo seu tamanho ideal para procedimentos cirúrgicos quanto por sua manutenção fácil e econômica. As células tronco derivadas do tecido adiposo (ADSC) consistem em um tipo de célula tronco mesenquimal multipotente que se destaca pela facilidade, rapidez e segurança de coleta e processamento. As ADSC foram coletadas e caracterizadas por meio de análises de curva de crescimento celular, doubling time, viabilidade após criopreservação, capacidade de formação de colônias fibroblastoides, diferenciação osteogênica, condrogênica e adipogênica, imunocitoquímica e citometria de fluxo. Elas demonstraram possuir as características básicas de células tronco mesenquimais, destacando-se por uma alta e rápida capacidade proliferativa. A indução de pluripotência foi realizada nas ADSC de coelhos pela introdução de quatro fatores de transcrição (OCT4, SOX2, cMYC, e KLF4), pelo vetor lentiviral STEMCCA (Milipore). Cinco protocolos de indução foram testados. Células resultantes da indução foram caracterizadas quanto à atividade da fosfatase alcalina e perfil fenotípico por citometria de fluxo. A proliferação acentuada das ADSC parece ser um fator limitante para a eficácia da reprogramação. A partir destes dados, espera-se contribuir para o desenvolvimento de uma tecnologia brasileira ainda inédita em coelhos e adicionar informações importantes à literatura, acerca das propriedades das células iPS, visando sua utilização como modelo experimental para futuras terapias. / Induced Pluripotent Stem (iPS) cells were first reported in 2006 by Takahashi e Yamanaka and has been intensively studied since then. Through the technique, adult somatic cells acquire behavior very similar to embryonic stem cells, reducing the ethical issues related to the use of such research. However, biological mechanisms of iPS cells are not yet fully elucidated. Thus, further research is needed to ensure the safety and efficacy for their possible use in future therapies. Rabbits, as experimental models, are advantageous by their ideal size for surgical procedures and easy and economic maintenance. Adipose Derived Stem Cells (ADSC) consists of multipotent mesenchymal stem cells that stand for ease, speed and safety of collection and processing. The ADSC were collected and characterized by analysis of cell growth curve, doubling time, viability after cryopreservation, ability of fibroblast colony formation, osteogenic, adipogenic and chondrogenic differentiation, immunocytochemistry and flow cytometry. They showed to have the basic characteristics of mesenchymal stem cells, standing out by a high and fast proliferative capacity. Induction of pluripotency was performed in rabbits ADSC by the introduction of four transcription factors (OCT4, SOX2, cMYC, and KLF4) by lentiviral vector STEMCCA (Millipore). Five protocols were tested and analyzed. The resulting cells after induction were characterized by alkaline phosphatase activity and phenotypic profile by flow cytometry. The great proliferation of ADSC seems to be detrimental for the reprogramming efficiency. From these data, it is expected to contribute to the development of a Brazilian technology still unpublished in rabbits, and to add important information to the literature about the properties of iPS cells, aiming their use as an experimental model for future therapies.

As células de pluripotência induzida (iPS) foram reportadas pela primeira vez em 2006 por Takahashi e Yamanaka e desde então vem sendo extensivamente estudadas. Por meio da técnica, células somáticas adultas adquirem comportamento muito semelhante às células tronco embrionárias, reduzindo as questões éticas relacionadas ao uso destas em pesquisas. Entretanto, os mecanismos biológicos das células iPS ainda não estão completamente elucidados. Ainda são necessárias pesquisas mais aprofundadas para garantir a segurança e eficácia de sua possível utilização em futuras terapias. Os coelhos, como modelos experimentais, são vantajosos tanto pelo seu tamanho ideal para procedimentos cirúrgicos quanto por sua manutenção fácil e econômica. As células tronco derivadas do tecido adiposo (ADSC) consistem em um tipo de célula tronco mesenquimal multipotente que se destaca pela facilidade, rapidez e segurança de coleta e processamento. As ADSC foram coletadas e caracterizadas por meio de análises de curva de crescimento celular, doubling time, viabilidade após criopreservação, capacidade de formação de colônias fibroblastoides, diferenciação osteogênica, condrogênica e adipogênica, imunocitoquímica e citometria de fluxo. Elas demonstraram possuir as características básicas de células tronco mesenquimais, destacando-se por uma alta e rápida capacidade proliferativa. A indução de pluripotência foi realizada nas ADSC de coelhos pela introdução de quatro fatores de transcrição (OCT4, SOX2, cMYC, e KLF4), pelo vetor lentiviral STEMCCA (Milipore). Cinco protocolos de indução foram testados. Células resultantes da indução foram caracterizadas quanto à atividade da fosfatase alcalina e perfil fenotípico por citometria de fluxo. A proliferação acentuada das ADSC parece ser um fator limitante para a eficácia da reprogramação. A partir destes dados, espera-se contribuir para o desenvolvimento de uma tecnologia brasileira ainda inédita em coelhos e adicionar informações importantes à literatura, acerca das propriedades das células iPS, visando sua utilização como modelo experimental para futuras terapias. / Induced Pluripotent Stem (iPS) cells were first reported in 2006 by Takahashi e Yamanaka and has been intensively studied since then. Through the technique, adult somatic cells acquire behavior very similar to embryonic stem cells, reducing the ethical issues related to the use of such research. However, biological mechanisms of iPS cells are not yet fully elucidated. Thus, further research is needed to ensure the safety and efficacy for their possible use in future therapies. Rabbits, as experimental models, are advantageous by their ideal size for surgical procedures and easy and economic maintenance. Adipose Derived Stem Cells (ADSC) consists of multipotent mesenchymal stem cells that stand for ease, speed and safety of collection and processing. The ADSC were collected and characterized by analysis of cell growth curve, doubling time, viability after cryopreservation, ability of fibroblast colony formation, osteogenic, adipogenic and chondrogenic differentiation, immunocytochemistry and flow cytometry. They showed to have the basic characteristics of mesenchymal stem cells, standing out by a high and fast proliferative capacity. Induction of pluripotency was performed in rabbits ADSC by the introduction of four transcription factors (OCT4, SOX2, cMYC, and KLF4) by lentiviral vector STEMCCA (Millipore). Five protocols were tested and analyzed. The resulting cells after induction were characterized by alkaline phosphatase activity and phenotypic profile by flow cytometry. The great proliferation of ADSC seems to be detrimental for the reprogramming efficiency. From these data, it is expected to contribute to the development of a Brazilian technology still unpublished in rabbits, and to add important information to the literature about the properties of iPS cells, aiming their use as an experimental model for future therapies.

A engenharia de tecidos tem despontado como uma estratégia promissora à regeneração de tecidos danificados, especialmente quando da associação de células-troncoa biomateriais. As características das células-tronco adiposoderivadas (CTAD), membro da família das células-tronco mesenquimais, tornam estas células uma ferramenta com grande potencial para este propósito. Por outro lado, biomateriais podem ser utilizados como substitutos artificiais da matriz extracelular, propiciando uma matriz de suporte para as células cultivadas in vitro.O objetivo deste trabalho foi investigar os parâmetros de aderência e de proliferação de CTAD humanas, caninas e murinas associadas a matrizes de biomateriais à base de colágeno, fosfato de cálcio eopen-cell poly (L-lactic acid) (OPLA) (BD Biosciences). Tecido adiposo foi obtido a partir de pacientes submetidos à lipoaspiração eletiva, cães sadios e camundongos da linhagem C57BL/6, respectivamente. O tecido adiposo foi submetido à digestão com colagenase e as CTADisoladas foram cultivadas e caracterizadas quanto à morfologia, taxa de proliferação e diferenciação e imunofenótipo. As células-tronco foram associadas às matrizes, em cultivos tridimensionais (3D), entre as passagens 4 e 7. As matrizes foram divididas em dois grupos: pré-incubadas em meio de cultivo suplementado com 10% de soro fetal bovino (pre-coating, PC),ou secas (dry, D). Duas concentrações celulares foram utilizadas: 104 e 5x104 células/matriz, e cultivos celulares convencionais (2D) foram realizados para comparar o índice de proliferação nas condições 2D x 3D. A taxa de aderência aos biomateriais foi avaliada pela contagem de células não aderidas após incubação de 3 horas. O índice de proliferação das CTAD, nas condições 2D e 3D, foi avaliado após 3 dias de incubação através do teste MTT. Os resultados mostram que as CTAD das três espécies apresentam as características típicas das células-tronco da linhagem mesenquimal e aderem preferencialmente aos biomateriais não submetidos à pré-incubação (D), naconcentração de 5x104 células/peça. As CTAD humanas apresentaram índice de proliferação mais elevado na condição 2D do que na condição 3D, enquanto as CTAD caninas e murinas tiveram comportamento oposto. Juntos, estes resultados indicam a possibilidade da associação de CTAD de diferentes espécies a biomateriais e a sua utilização em aplicações clínicas. / Tissue engineering has emerged as a promising strategy for regeneration of damaged tissues, especially when stem cells are associated to biomaterials. The characteristics of adipose-derived stem cells (ADSC), which are a type of mesenchymal stem cells, makethem a tool with great therapeutic potential. Different types of biomaterials can be used as artificial substitutes of the extracellular matrix, providing a support matrix for in vitro cell culture. The present study aimed to isolate and characterize human, canine and murine ADSC, and toinvestigate the patterns of adhesion and proliferation of these cells after association with collagen-based biomaterials, open-cell poly (L-lactic acid) (OPLA) and calcium phosphate (BD Biosciences). Adipose tissue was obtained from patients undergoing elective liposuction, healthy dogs, and C57BL/6 mice, respectively. The tissue was digested with collagenase and the isolated ADSC were cultured and characterized for morphology, immunophenotype and proliferation and differentiation potential. Cells were associated to biomaterials scaffolds, for tridimensional (3D) cultivation, between passages 4 and 7. The biomaterials were divided into two groups: one was previously pre-incubated with culture medium supplemented with 10% of fetal bovine serum (pre-coating, PC), and the other was not (dry, D). Two cell concentrations were used, 104 and 5x104 cells/scaffold, and conventional cell cultures (2D) were performed to compare the rate of proliferation in 3D x 2D systems. The rate of adhesion was assessed by counting the non-adhered cells after 3-hour incubation with the scaffolds. The proliferation index of ADSC cultivated under 2D conditions was measured after 3-day incubation by the MTT assay. The results show that ADSC from the three species present features characteristic of mesenchymal stem cells, and adhere more to scaffolds not submitted to pre-incubation (D),at the concentration of 5x104 cells/scaffold. Human ADSC showed higher proliferation index in 2D condition than in the 3D condition, contrary to canine and murine ADSC. Together, these results indicate that association of ADSCfrom different species to biomaterials is feasible and may be exploited for clinical applications.

A engenharia de tecidos tem despontado como uma estratégia promissora à regeneração de tecidos danificados, especialmente quando da associação de células-troncoa biomateriais. As características das células-tronco adiposoderivadas (CTAD), membro da família das células-tronco mesenquimais, tornam estas células uma ferramenta com grande potencial para este propósito. Por outro lado, biomateriais podem ser utilizados como substitutos artificiais da matriz extracelular, propiciando uma matriz de suporte para as células cultivadas in vitro.O objetivo deste trabalho foi investigar os parâmetros de aderência e de proliferação de CTAD humanas, caninas e murinas associadas a matrizes de biomateriais à base de colágeno, fosfato de cálcio eopen-cell poly (L-lactic acid) (OPLA) (BD Biosciences). Tecido adiposo foi obtido a partir de pacientes submetidos à lipoaspiração eletiva, cães sadios e camundongos da linhagem C57BL/6, respectivamente. O tecido adiposo foi submetido à digestão com colagenase e as CTADisoladas foram cultivadas e caracterizadas quanto à morfologia, taxa de proliferação e diferenciação e imunofenótipo. As células-tronco foram associadas às matrizes, em cultivos tridimensionais (3D), entre as passagens 4 e 7. As matrizes foram divididas em dois grupos: pré-incubadas em meio de cultivo suplementado com 10% de soro fetal bovino (pre-coating, PC),ou secas (dry, D). Duas concentrações celulares foram utilizadas: 104 e 5x104 células/matriz, e cultivos celulares convencionais (2D) foram realizados para comparar o índice de proliferação nas condições 2D x 3D. A taxa de aderência aos biomateriais foi avaliada pela contagem de células não aderidas após incubação de 3 horas. O índice de proliferação das CTAD, nas condições 2D e 3D, foi avaliado após 3 dias de incubação através do teste MTT. Os resultados mostram que as CTAD das três espécies apresentam as características típicas das células-tronco da linhagem mesenquimal e aderem preferencialmente aos biomateriais não submetidos à pré-incubação (D), naconcentração de 5x104 células/peça. As CTAD humanas apresentaram índice de proliferação mais elevado na condição 2D do que na condição 3D, enquanto as CTAD caninas e murinas tiveram comportamento oposto. Juntos, estes resultados indicam a possibilidade da associação de CTAD de diferentes espécies a biomateriais e a sua utilização em aplicações clínicas. / Tissue engineering has emerged as a promising strategy for regeneration of damaged tissues, especially when stem cells are associated to biomaterials. The characteristics of adipose-derived stem cells (ADSC), which are a type of mesenchymal stem cells, makethem a tool with great therapeutic potential. Different types of biomaterials can be used as artificial substitutes of the extracellular matrix, providing a support matrix for in vitro cell culture. The present study aimed to isolate and characterize human, canine and murine ADSC, and toinvestigate the patterns of adhesion and proliferation of these cells after association with collagen-based biomaterials, open-cell poly (L-lactic acid) (OPLA) and calcium phosphate (BD Biosciences). Adipose tissue was obtained from patients undergoing elective liposuction, healthy dogs, and C57BL/6 mice, respectively. The tissue was digested with collagenase and the isolated ADSC were cultured and characterized for morphology, immunophenotype and proliferation and differentiation potential. Cells were associated to biomaterials scaffolds, for tridimensional (3D) cultivation, between passages 4 and 7. The biomaterials were divided into two groups: one was previously pre-incubated with culture medium supplemented with 10% of fetal bovine serum (pre-coating, PC), and the other was not (dry, D). Two cell concentrations were used, 104 and 5x104 cells/scaffold, and conventional cell cultures (2D) were performed to compare the rate of proliferation in 3D x 2D systems. The rate of adhesion was assessed by counting the non-adhered cells after 3-hour incubation with the scaffolds. The proliferation index of ADSC cultivated under 2D conditions was measured after 3-day incubation by the MTT assay. The results show that ADSC from the three species present features characteristic of mesenchymal stem cells, and adhere more to scaffolds not submitted to pre-incubation (D),at the concentration of 5x104 cells/scaffold. Human ADSC showed higher proliferation index in 2D condition than in the 3D condition, contrary to canine and murine ADSC. Together, these results indicate that association of ADSCfrom different species to biomaterials is feasible and may be exploited for clinical applications.

A engenharia de tecidos tem despontado como uma estratégia promissora à regeneração de tecidos danificados, especialmente quando da associação de células-troncoa biomateriais. As características das células-tronco adiposoderivadas (CTAD), membro da família das células-tronco mesenquimais, tornam estas células uma ferramenta com grande potencial para este propósito. Por outro lado, biomateriais podem ser utilizados como substitutos artificiais da matriz extracelular, propiciando uma matriz de suporte para as células cultivadas in vitro.O objetivo deste trabalho foi investigar os parâmetros de aderência e de proliferação de CTAD humanas, caninas e murinas associadas a matrizes de biomateriais à base de colágeno, fosfato de cálcio eopen-cell poly (L-lactic acid) (OPLA) (BD Biosciences). Tecido adiposo foi obtido a partir de pacientes submetidos à lipoaspiração eletiva, cães sadios e camundongos da linhagem C57BL/6, respectivamente. O tecido adiposo foi submetido à digestão com colagenase e as CTADisoladas foram cultivadas e caracterizadas quanto à morfologia, taxa de proliferação e diferenciação e imunofenótipo. As células-tronco foram associadas às matrizes, em cultivos tridimensionais (3D), entre as passagens 4 e 7. As matrizes foram divididas em dois grupos: pré-incubadas em meio de cultivo suplementado com 10% de soro fetal bovino (pre-coating, PC),ou secas (dry, D). Duas concentrações celulares foram utilizadas: 104 e 5x104 células/matriz, e cultivos celulares convencionais (2D) foram realizados para comparar o índice de proliferação nas condições 2D x 3D. A taxa de aderência aos biomateriais foi avaliada pela contagem de células não aderidas após incubação de 3 horas. O índice de proliferação das CTAD, nas condições 2D e 3D, foi avaliado após 3 dias de incubação através do teste MTT. Os resultados mostram que as CTAD das três espécies apresentam as características típicas das células-tronco da linhagem mesenquimal e aderem preferencialmente aos biomateriais não submetidos à pré-incubação (D), naconcentração de 5x104 células/peça. As CTAD humanas apresentaram índice de proliferação mais elevado na condição 2D do que na condição 3D, enquanto as CTAD caninas e murinas tiveram comportamento oposto. Juntos, estes resultados indicam a possibilidade da associação de CTAD de diferentes espécies a biomateriais e a sua utilização em aplicações clínicas. / Tissue engineering has emerged as a promising strategy for regeneration of damaged tissues, especially when stem cells are associated to biomaterials. The characteristics of adipose-derived stem cells (ADSC), which are a type of mesenchymal stem cells, makethem a tool with great therapeutic potential. Different types of biomaterials can be used as artificial substitutes of the extracellular matrix, providing a support matrix for in vitro cell culture. The present study aimed to isolate and characterize human, canine and murine ADSC, and toinvestigate the patterns of adhesion and proliferation of these cells after association with collagen-based biomaterials, open-cell poly (L-lactic acid) (OPLA) and calcium phosphate (BD Biosciences). Adipose tissue was obtained from patients undergoing elective liposuction, healthy dogs, and C57BL/6 mice, respectively. The tissue was digested with collagenase and the isolated ADSC were cultured and characterized for morphology, immunophenotype and proliferation and differentiation potential. Cells were associated to biomaterials scaffolds, for tridimensional (3D) cultivation, between passages 4 and 7. The biomaterials were divided into two groups: one was previously pre-incubated with culture medium supplemented with 10% of fetal bovine serum (pre-coating, PC), and the other was not (dry, D). Two cell concentrations were used, 104 and 5x104 cells/scaffold, and conventional cell cultures (2D) were performed to compare the rate of proliferation in 3D x 2D systems. The rate of adhesion was assessed by counting the non-adhered cells after 3-hour incubation with the scaffolds. The proliferation index of ADSC cultivated under 2D conditions was measured after 3-day incubation by the MTT assay. The results show that ADSC from the three species present features characteristic of mesenchymal stem cells, and adhere more to scaffolds not submitted to pre-incubation (D),at the concentration of 5x104 cells/scaffold. Human ADSC showed higher proliferation index in 2D condition than in the 3D condition, contrary to canine and murine ADSC. Together, these results indicate that association of ADSCfrom different species to biomaterials is feasible and may be exploited for clinical applications.

La thérapie cellulaire constitue une stratégie prometteuse dans le traitement de l'infarctus du myocarde. Afin de mieux contrôler la survie, la différenciation et l'intégration des cellules greffées, nous avons tenté une approche d'ingénierie tissulaire en associant les cellules à un microvecteur comportant une surface biomimétique et pouvant libérer un facteur de croissance (FC), les microcarriers pharmacologiquement actifs (MPA). Parmi les cellules utilisées dans une telle approche, les cellules souches adultes dérivées du tissu adipeux (ADSC) ne soulèvent pas de problèmes d'ordre éthique et permettent de réaliser des greffes autologues. Ces cellules sont largement étudiées pour la régénération de nombreux tissus en vertu de leurs propriétés immuno-modulatrices, de leur capacité à sécréter des FC et chémokines, mais également de leur large potentiel de différenciation. Dans une première étape, nous avons étudié l'effet des molécules de la matrice extracellulaire et des MPA sur la différentiation en cardiomyocytes des ADSC en présence d'un cocktail de FC. Nous avons ainsi pu observer que l'apport du cocktail de FC permettait aux cellules de s'engager dans la voie de différentiation cardiaque après 2 semaines. En comparant l'effet de la laminine (LM) et de la fibronectine sur cette différentiation, nous avons pu observer que la LM permettait d'induire une différentiation dans une cellule plus mature et que ceci était potentialisée par un enrichissement du milieu en TGF!1. Finalement, l'apport de MPA recouverts de LM favorisait une différentiation plus rapide des cellules en présence du cocktail. Les MPA peuvent également libérer un facteur de croissance de manière prolongée au cours du temps. Par conséquent, nous avons encapsulé 3 protéines, le VEGF, le HGF et l'IGF-1, et d'étudier leur effet sur les comportement des ADSC. Nous avons ainsi pu observer que des MPA libérant du HGF et de l'IGF-1 induisaient une différenciation de ADSC dans la voie cardiaque et que cette différentiation était également observée lorsque les complexes ADSCMPA étaient intégrés dans un hydrogel thermosensible. Cependant, nous avons aussi observé que la quantité de protéines libérées à partir des MPA était plus faible dans le gel. Nous avons donc cherché dans une dernière partie à améliorer le profile de libération des protéines à partir des MPA en changeant la composition du polymère. Nous avons ainsi utilisé différents copolymères triblock PLGA-PEG-PLGA pour formuler des microsphères et évaluer leur rôle sur la libération de la protéine mais aussi sur la stabilité de celle-ci durant la dégradation du polymère.

Enxertos livres de pele de espessura total são indicados para cobrir grandes defeitos de pele em superfícies flexoras ou em extremidades distais e sofrem lesão por isquemia e reperfusão pela própria natureza do procedimento cirúrgico. O objetivo deste trabalho foi testar a associação de células tronco mesenquimais de origem adiposa (ADSCs) heterólogas a enxertos cutâneos autólogos de espessura total em ratos Wistar. Enxertos de 12 mm de diâmetro foram executados no dorso de 30 ratos, em dois locais: cranial e caudal. Os ratos foram distribuídos em seis grupos (n=5): grupo ADSC_G recebeu, no enxerto, 1x106 ADSCs em 200 μL de Solução Salina 0,9% (SS); grupo ADSC_B recebeu 1x106 ADSCs em 200 μL de SS na borda do leito receptor; grupo ADSC_GB, metade da mesma suspensão na borda e outra metade no enxerto. Os grupos controle, SS_G e SS_B, receberam apenas SS no enxerto ou nas bordas respectivamente. No grupo S, o enxerto não recebeu nenhum tratamento durante as cirurgias. Curativos do tipo tie-over permaneceram até o 5º dia. Na cirurgia (d0), aos 5 (d5) e 14 (d14) dias de pós-operatório, os desenhos dos enxertos foram digitalizados e suas áreas mensuradas (software ImageJ). As avalições clínicas consideraram peso, presença de secreções e ocorrência de epidermólise. A planimetria demonstrou a taxa de pele normal, de pele avermelhada e de ulceração, assim como a contração dos enxertos entre os intervalos d0–d5, d5-d14 e d0-d14. As amostras dos enxertos foram obtidas em d14 para coloração com Hematoxilina e eosina e Tricrômico de Masson. A epiderme foi avaliada para espessamento, ceratose, acantose, degeneração hidrópica, infiltrado inflamatório. A derme foi avaliada quanto a rarefação pilosa, tecido de granulação, infiltrado inflamatório, deposição de colágeno. Os resultados foram expressos em média e desvio padrão, e a análise estatística utilizou as Equações de Estimações Generalizadas (GEE), com nível de significância de 5%. O grupo ADSC_G apresentou melhores aspectos macroscópicos, menos ocorrência de epidermólise e de rarefação pilosa e uma das menores médias de área de ulceração, juntamente com os outros grupos tratados com ADSCs. O grupo ADSC_G demonstrou as menores médias de alterações histopatológicas como: espessamento da epiderme, degeneração hidrópica, tecido de granulação. O mesmo grupo ficou entre as menores médias de acantose e infiltrado inflamatório na derme, ao mesmo tempo que apresentou as maiores médias de VEGF no subcutâneo e no tecido de granulação. Dessa forma, pode-se concluir que as ADSCs protegeram os enxertos dos efeitos deletérios da isquemia, assim como e sugerem-se novos estudos em fases iniciais da cicatrização para compreensão dos mecanismos envolvidos. / Evaluation of adipose derived stem cells (ADSC) effect on full-thickness skin graft (FTSG) as a wound healing model in ischemic conditions. Two 12 mm diameter FTSGs were harvested and placed onto dorsal recipient beds of twenty-four Wistar rats, in two anatomic regions: cranial and caudal. Rats were randomized into five groups. Before grafting, group E FTSGs received subfascial injection of 1X106 ADSCs diluted in 200 μL of physiologic saline. Group EC FTSGs received only physiologic saline. Group B received ADSCs in the recipient bed edges; group C received physiologic saline in the edges. Group ADSC_GB received the same ADSCs number and volume, half in the graft and half in the edges. Using planimetry, grafts were analyzed for graft´s contraction rate (d0, d5, d14), normal skin rate and occurrence of epidermolysis and failure rate (d14). FTSGs samples were obtained on the d14 to hematoxylin-eosin and Masson’s Trichrome staining for epidermal analysis (epidermal thickening, keratosis, acanthosis, hydropic degeneration, inflammatory infiltrate) and dermal analysis (hairless, granulation tissue, inflammatory infiltrate, collagen deposition). The obtained results were expressed by mean (n=5). Statistical significance (p<0,05) was calculated using Generalized Estimating Equations. The ADSC_G group had better macroscopic aspects, less occurrence of epidermolysis and hairless and one of the lowest averages of ulceration area, along with the other groups treated with ADSCs. The ADSC_G group showed the lowest mean on the histopathological changes measured such as thickening of the epidermis, hydropic degeneration, less granulation tissue. The same group was among the lowest acanthosis and inflammatory infiltrate averages in the dermis, while presented with the greatest of VEGF average in the subcutaneous and in the granulation tissue. Thus it can be concluded that the ADSCs may have protected the grafts from the deleterious effects of ischemia and suggest new studies in the early stages of healing to understand the mechanisms involved.