5 resultados para tissue transplantation

em CiencIPCA - Instituto Politécnico do Cávado e do Ave, Portugal


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Protein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing to be dependent of concentration and solvent used. Treatment with air saturated with methanol was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into β-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570-720%), water vapour transmission rate (1083 g/m2/day) and mechanical properties (modulus of elasticity of ~126 MPa). Furthermore, the methanol-treated SELP fiber mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fiber mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications.

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This work reports on the influence of polarization and morphology of electroactive poly(vinylidene fluoride), PVDF, on the biological response of myoblast cells. Non-poled, ‘‘poled +’’ and “poled-“ -PVDF were prepared in the form of films. Further, random and aligned electrospun -PVDF fiber mats were also prepared. It is demonstrated that negatively charged surfaces improve cell adhesion and proliferation and that the directional growth of the myoblast cells can be achieved by the cell culture on oriented fibers. Therefore, the potential application of electroative materials for muscle regeneration is demonstrated.

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Background: Surgical repair of pectus excavatum (PE) has become more popular due to improvements in the minimally invasive Nuss procedure. The pre-surgical assessment of PE patients requires Computerized Tomography (CT), as the malformation characteristics vary from patient to patient. Objective: This work aims to characterize soft tissue thickness (STT) external to the ribs among PE patients. It also presents a comparative analysis between the anterior chest wall surface before and after surgical correction. Methods: Through surrounding tissue segmentation in CT data, STT values were calculated at different lines along the thoracic wall, with a reference point in the intersection of coronal and median planes. The comparative analysis between the two 3D anterior chest surfaces sets a surgical correction influence area (SCIA) and a volume of interest (VOI) based on image processing algorithms, 3D surface algorithms, and registration methods. Results: There are always variations between left and right side STTs (2.54±2.05 mm and 2.95±2.97 mm for female and male patients, respectively). STTs are dependent on age, sex, and body mass index of each patient. On female patients, breast tissue induces additional errors in bar manual

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Abstract: § 1 «Do we need a “new” international convention that helps to avoid trafficking in organs? Some criminal (and civil) law aspects”» - «Convention on Human Rights and Biomedicine – updated or outdated?». § 2 Some important connections: on the one hand, between the 1997 Council of Europe Convention on Human Rights and Biomedicine; the 2002 Additional Protocol to the Convention on Human Rights and Biomedicine concerning Transplantation of Organs and Tissues of Human Origin; and, on the other hand, the problem of trafficking in organs, tissues and cells and trafficking in human beings for the purpose of the removal organs. Some connections. § 3 The «international undisputed principle». § 4 Trafficking in organs, tissues and cells; and trafficking in human beings for the purpose of the removal organs. Criminal Law and Civil Law. § 5 Promote organ donation. § 6 The necessity to collect reliable data on both trafficking cases. § 7 The necessity for an internationally agreed definition of trafficking in OTC: Convention on Human Rights and Biomedicine – updated or outdated? § 8 The (inter)national and (il)legal organ («tissue and cell») trade: some cases and some conclusions. § 9 Do we need a new international convention to prevent trafficking in organs, tissues and cells (OTC)? § 10 Of course we need a «new» international convention to prevent trafficking in organs, tissues and cells (OTC). § 11 At the present moment, we do not need a «new» international convention to prevent trafficking in human beings for the purpose of the removal organs. § 12 The Portuguese case. § 13 «Final conclusions.» § Resumo: § 1 «Precisamos de uma "nova" convenção internacional que ajude a evitar o tráfico de órgãos? Alguns aspectos de lei criminal (e civil)» - «Convenção sobre Direitos Humanos e Biomedicina - Actualizada ou desactualizada?». § 2 Algumas conexões importantes: por um lado, entre a Convenção do Conselho da Europa de 1997 sobre Direitos Humanos e Biomedicina; o Protocolo Adicional de 2002 à Convenção sobre os Direitos do Homem e da Biomedicina relativo ao transplante de órgãos e tecidos de origem humana, e, por outro lado, o problema do tráfico de órgãos, tecidos e células e tráfico de seres humanos para fins de remoção dos órgãos. § 3 O «indiscutível princípio internacional». § 4 O Tráfico de órgãos, tecidos e células; e o tráfico de seres humanos para fins de remoção dos órgãos. Direito Penal e Direito Civil. § 5 Promover a doação de órgãos. § 6 A necessidade de colectar dados fidedignos sobre os dois casos de tráfico. § 7 A necessidade de uma definição internacionalmente acordada de tráfico de OTC: Convenção sobre Direitos Humanos e Biomedicina - actualizada ou desactualizada? § 8 A (inter)nacional e (il)legal comercialização de órgãos («de tecidos e de células»): alguns casos e algumas conclusões. § 9 Será que precisamos de uma nova convenção internacional para prevenir o tráfico de órgãos, tecidos e células (OTC)? § 10 É claro que precisamos de uma «nova» convenção internacional para prevenir o tráfico de órgãos, tecidos e células (OTC). § 11 No presente momento, não precisamos de uma «nova» convenção internacional para impedir o tráfico de seres humanos para fins de remoção dos órgãos. § 12 O caso Português. § 13 «As conclusões finais.»

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Background: Surgical repair of pectus excavatum (PE) has become more popular due to improvements in the minimally invasive Nuss procedure. The pre-surgical assessment of PE patients requires Computerized Tomography (CT), as the malformation characteristics vary from patient to patient. Objective: This work aims to characterize soft tissue thickness (STT) external to the ribs among PE patients. It also presents a comparative analysis between the anterior chest wall surface before and after surgical correction. Methods: Through surrounding tissue segmentation in CT data, STT values were calculated at different lines along the thoracic wall, with a reference point in the intersection of coronal and median planes. The comparative analysis between the two 3D anterior chest surfaces sets a surgical correction influence area (SCIA) and a volume of interest (VOI) based on image processing algorithms, 3D surface algorithms, and registration methods. Results: There are always variations between left and right side STTs (2.54±2.05 mm and 2.95±2.97 mm for female and male patients, respectively). STTs are dependent on age, sex, and body mass index of each patient. On female patients, breast tissue induces additional errors in bar manual