Scaffolds Vasculares Descelularizados Provenientes de Vasos Sanguíneos de Placenta Bovina / Decellularized Vascular Scaffolds Derived from Bovine Placenta Blood Vessels

Resumo Fundamento As doenças associadas ao aparelho circulatório são as principais causas de morbidade e mortalidade em todo o mundo, implicando a necessidade de implantes vasculares. Assim, a produção de biomateriais vasculares tem se mostrado uma alternativa promissora às terapias utilizadas em estudos e pesquisas relacionados à fisiologia vascular. Objetivos O presente projeto visa ao desenvolvimento artificial de vasos sanguíneos pela recelularização de scaffolds vasculares derivados de vasos placentários bovinos. Métodos A superfície corioalantoide da placenta bovina foi utilizada para produzir biomateriais descelularizados. Para a recelularização, 2,5 x 104 células endoteliais foram semeadas acima de cada fragmento de vaso descelularizado durante três ou sete dias, quando a cultura foi interrompida e os fragmentos foram fixados para análise de adesão celular. Biomateriais descelularizados e recelularizados foram avaliados por histologia básica, microscopia eletrônica de varredura e imuno-histoquímica. Resultados o processo de descelularização produziu vasos que mantiveram a estrutura natural e o conteúdo de elastina, e não foram observadas células e gDNA remanescentes. Além disso, células precursoras endoteliais se ligaram ao lúmen e à superfície externa do vaso descelularizado. Conclusão nossos resultados mostram a possibilidade de usos futuros desse biomaterial na medicina cardiovascular, como, por exemplo, no desenvolvimento de vasos artificiais.

Background Diseases associated with the circulatory system are the main causes of worldwide morbidity and mortality, implying the need for vascular implants. Thus, the production of vascular biomaterials has proven to be a promising alternative to therapies used in studies and research related to vascular physiology. Objectives The present project aims to achieve the artificial development of blood vessels through the recellularization of vascular scaffolds derived from bovine placental vessels. Methods The chorioallantoic surface of the bovine placenta was used to produce decellularized biomaterials. For recellularization, 2.5 x 104 endothelial cells were seeded above each decellularized vessel fragment during three or seven days, when culture were interrupted, and the fragments were fixed for cell attachment analysis. Decellularized and recellularized biomaterials were evaluated by basic histology, scanning electron microscopy, and immunohistochemistry. Results The decellularization process produced vessels that maintained natural structure and elastin content, and no cells or gDNA remains were observed. Endothelial precursor cells were also attached to lumen and external surface of the decellularized vessel.Conclusion: Our results show a possibility of future uses of this biomaterial in cardiovascular medicine, as in the development of engineered vessels.

Rabbit olfactory stem cells. Isolation protocol and characterization

PURPOSE: To describe a new technique for isolation of a mesenchymal stem cells (MSCs) population from the olfactory mucosa in rabbits. METHODS: Olfactory stem cells (OSCs) were retrieved from under the cribriform plate of the Ethmoid bone. Several assays were accomplished to characterize the cell population and attest its viability in vitro. The cells were submitted to flow cytometry with the antibodies CD34, CD45, CD73, CD79, CD90 and CD105 and also they were induced to differentiate in three lineages. Functional evaluation involved analysis of in vitro growth behavior, colony forming unit like fibroblasts (CFU-f) and cryopreservation response. Further transduction with Green Fluorescent Protein (GFP) was also performed. RESULTS: The OSCs showed mesenchymal features, as positive response to CD34, CD73 and CD90 antibodies and plasticity. Additionally, these cells have high proliferated rate, and they could be cultured through many passages and kept the ability to proliferate and differentiate after cryopreservation. The positive response to the transduction signalizes the possibility of cellular tracking in vivo. This is a desirable feature in case those cells are used for pre-clinical trials. CONCLUSION: The cells harvested were mesenchymal stem cells and the technique described is therefore efficient for rabbit olfactory stem cells isolation.

Caracterização da fusão caruncular em gestações naturais e de conceptos bovinos clonados / Characterization of the caruncular fusion in gestations of natural and cloned bovine conceptuses

O objetivo deste trabalho foi comparar as fusões carunculares em gestações de conceptos não clonados (CNC) e conceptos clonados (CC). Os CNC foram divididos segundo o período de gestação em Grupo I (2-3 meses, n=9), Grupo II (4-6 meses, n=9), Grupo III (7-8 meses, n=10) e Grupo IV (9 meses, n=7). Os CC formaram o Grupo V (9 meses, n=4). As carúnculas foram observadas macroscopicamente (número e dimensões: comprimento, largura e altura), microscopicamente e submetidas à análise estatística (5 por cento de significância). Observaram-se três tipos de fusões carunculares macroscópicas: ovais (morfologicamente normais); duas carúnculas adjacentes unidas e do tipo lobuladas, caracterizadas por regiões com várias carúnculas unidas apresentando falsa fusão ou deformação do parênquima caruncular. O comprimento das carúnculas foi de 1,55±0,57; 2,45±0,55; 4,66±2,00 e 5,72±1,90cm para os Grupos I, II, III e IV, respectivamente. Quanto à altura, as carúnculas apresentaram um crescimento linear durante a gestação e foram de 0,40±0,15; 0;57±0,21; 1,00±0,48 e 1,80±0,91cm, para os respectivos Grupos I, II, III e IV. A largura das carúnculas foi semelhante entre os Grupos I e II (0,97±0,30 e 1,42±0,71cm) e os Grupos III e IV (2,68±1,22 e 3,52±1,16cm). Quando o Grupo V foi comparado ao Grupo IV, as carúnculas do Grupo V apresentaram maior comprimento (5,72±1,90 vs. 7,88±2,13cm) e largura (3,52±1,16 vs. 4,93±1,46cm), porém foram semelhantes em altura (1,80±0,91 e 2,25±0,67cm). Verificou-se que em gestações de CC, as carúnculas apresentaram maior desenvolvimento que em gestações de CNC. As carúnculas fusionadas apresentaram medidas estatisticamente semelhantes às isoladas em todos os parâmetros e grupos. Sob microscopia de luz, observou-se a formação de um eixo estromal, da base da carúncula ao ápice da fissura fusional, de constituição histológica semelhante ao estroma endometrial. Também foram ineditamente definidos três formatos microscópicos: fusão propriamente ...

The objective of the study was to compare the characteristics of the caruncular fusion in gestations of non-cloned and cloned conceptuses. The non-cloned conceptuses were divided according to the gestation period: Group I (2 to 3 months; n=9), II (4 to 6; n=9); III (7 to 8; n=10) and IV (9 n=7). The cloned conceptuses formed the Group V: 9 months; n=4. The caruncles were observed macroscopically (number and dimensions: length, width and height), microscopically and submitted to statistical analysis (5 percent of significance). We observed three types of macroscopic caruncular fusions: oval (morphologically normal); two united adjacent caruncles and the lobulated type, characterized by regions with several united caruncles presenting a false fusion or deformation of the caruncular parenchyma. The length of the caruncles was 1.55±0.57; 2.45±0.55; 4.66±2.0 and 5.72±1.90cm for the groups I, II, III, IV respectively. As for the height, the caruncles presented a lineal growth during the gestation: 0.40±0.15; 0.57±0.21; 1.0±0.48 and 1.80±0.91cm, for the respective groups I, II, III and IV. The width of the caruncles was similar between the groups I and II (0.97±0.30 e 1.42±0.71cm) and the groups III and IV (2.68±1.22 and 3.52±1.16cm). When the group V was compared to the IV, the caruncles of the group V presented a larger length (5.72±1.90 vs. 7.88±.13cm) and width (3.52±1.16 vs. 4.93±1.46cm), however they were similar in height (1.80±0.91 and 2.25±0.67cm). We verified that in gestations of cloned conceptuses the caruncles presented a larger development than in gestations of non-cloned conceptuses. The fusioned caruncles presented measurements statistically similar to the isolated ones in all the parameters and groups. Under light microscopy, we observed the formation of a stromal axis from the basis of the caruncle to the apex of the fusional fissure, with the histological constitution similar to the endometrial stroma. Three microscopic shapes ...