Orientador: Inez Valeria Pagotto Yoshida / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-04T16:15:53Z (GMT). No. of bitstreams: 1 Deangelo_CristinaAlves_M.pdf: 4120321 bytes, checksum: 89116fad862ad14079299ec810b0b04b (MD5) Previous issue date: 2004 / Mestrado / Quimica Inorganica / Mestre em Química

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-10T19:06:53Z No. of bitstreams: 1 LEANDRO RODRIGUES PEREIRA - DISSERTAÇÃO PPG-CEMat 2014..pdf: 3148791 bytes, checksum: 14fe302e950234a170c84cd8636b58ad (MD5) / Made available in DSpace on 2018-04-10T19:06:53Z (GMT). No. of bitstreams: 1 LEANDRO RODRIGUES PEREIRA - DISSERTAÇÃO PPG-CEMat 2014..pdf: 3148791 bytes, checksum: 14fe302e950234a170c84cd8636b58ad (MD5) Previous issue date: 2014-07-17 / Desde o final do século XIX, foram utilizados vários materiais para o aumento da mama. Como exemplos, citam-se espumas de poliuretano e polietileno, bolas de vidro, gutta percha, entre outros. O uso de silicone para fins de aumento de mama se iniciou em 1961 e, partir de então, as empresas desenvolveram inovações ao processo de fabricação de implantes mamários incluindo a inserção de camadas de barreiras para evitar a migração de gel. Em 2012, foi publicada a Resolução ANVISA RDC nº 16 que estabeleceu os requisitos mínimos de identidade e qualidade para os implantes mamários de silicone. Desta forma, este trabalho propõe a avaliar os implantes mamários regularizados no Brasil e realizar a caracterização morfológica, estrutural e mecânica de implantes mamários de silicone comercializados no Brasil em conformidade com as Normas Vigentes, por meio de caracterizações: Microscopia Ótica – MO, Microscopia Eletrônica de Varredura – MEV com espectroscopia de Energia Dispersiva- EDS e avaliação do comportamento mecânico quando submetidos ao Ensaio de Tração, sendo avaliados os quesitos estabelecidos na norma ISO 14607:2007. Com base nos resultados obtidos neste trabalho pode-se concluir que todas as membranas de implantes mamários avaliadas apresentaram-se adequadas para uso como biomaterial. Verificou-se também a oportunidade de melhoria normativa, com estabelecimento de parâmetro mínimo de desempenho para o ensaio de resistência ao rasgo, estabelecido na norma ISO 14607:2007. / Since the late nineteenth century, various materials were used for breast augmentation. Polyurethane, polyethylene, glass balls, gutta percha, among others materials were used. The use of silicone for breast augmentation purposes began in 1961 and, since then, companies have developed innovations to the manufacturing process of breast implants including the insertion of barrier layers to prevent migration of silicone gel. In 2012 was published the ANVISA Resolution RDC No. 16 which established minimum requirements for identity and quality for silicone breast implants. Thus, this study aims to evaluate six brands of regularized breast implants in Brazil and perform morphological, structural and mechanical caracterization in accordance with current standards. Optical Microscopy - MO, Electron Microscopy Scanning - SEM with Energy Dispersive Spectroscopy- EDS and evaluation of the mechanical behavior when subjected to tensile test according to ISO 14607:2007 standard. Based on the results obtained in this study, it can be concluded that all the membranes of breast implants had to be suitable for use as a biomaterial, complying with regulatory requirements. There is also an opportunity to improve the ISO 14607:2007 standard, establishing a minimum performance requirement for testing elastomer shell tear resistance.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-18T17:17:40Z No. of bitstreams: 1 WALFREDO DA SILVA CALMON - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2111423 bytes, checksum: e64a02519d1c3b8005ac197552feadca (MD5) / Made available in DSpace on 2018-04-18T17:17:40Z (GMT). No. of bitstreams: 1 WALFREDO DA SILVA CALMON - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2111423 bytes, checksum: e64a02519d1c3b8005ac197552feadca (MD5) Previous issue date: 2014-08-14 / Este trabalho tem por objetivo avaliar membranas de silicone que envolve o implante mamário preenchido com gel de silicone, no intuito de verificar a conformidade das suas propriedades. Como estratégia utilizou-se das técnicas de caracterização para analisar os parâmetros físico-químicos em três lotes diferentes de implante mamário. Os resultados experimentais encontrados foram comparados com valores referenciados em padrões estabelecidos em norma ou na literatura. Com isso, foi possível analisar alguns atributos que influenciam na qualidade desses implantes. Os resultados de microscopia por MO e MEV não detectaram anomalias nas superfícies das amostras. Foram detectados pelo ensaio de espectroscopia por EDS os elementos carbono, silício e oxigênio, como também identificados os metais ferro, cálcio, níquel e cromo nas amostras ensaiadas. O teste de alongamento de duas amostras não atendeu o requisito normativo. Conclui-se, portanto, que a integridade das membranas de silicone foi comprometida, por conta do seu comportamento mecânico, em duas das três amostras ensaiadas. / This work aims to evaluate silicon membranes surrounding the breast implant filled with silicone gel, in order to verify the conformity of its properties. As a strategy, we used the characterization techniques to analyze the physicochemical parameters in three different batches of breast implant. The experimental results were compared with values referenced in standard or standards established in the literature. Thus, it was possible to analyze some attributes that influence the quality of these implants. The results of OM and SEM microscopy did not detect anomalies in the surfaces of the samples. Were detected by testing the EDS spectra of carbon, silicon and oxygen elements, also identified as metals iron, calcium, nickel and chromium in the test samples. The stretching test two samples did not meet the regulatory requirement. Therefore, it is concluded that the integrity of the silicone membranes was compromised, because its mechanical behavior, in two of the three samples tested.

Einleitung Müssen im Verlauf einer kardiovaskulären Erkrankung geschädigte Gefäßabschnitte ersetzt werden, stehen den Gefäßchirurgen neben organischen Eigen– oder Fremdmaterial hauptsächlich die Kunststoffe Polytetraflourethylen (PTFE) und Polyethylen-terephtalat (PET, Polyester, Dacron®) zum Gefäßersatz zur Verfügung. Im Zusammenhang mit diesen künstlichen Ersatzmaterialien kommt es allerdings häufig zu Komplikationen. Diese sind besonders nach Rekonstruktion kleiner Gefäße durch die Thrombogenität ihrer Oberflächen und eine übersteigerte Intimahyperplasie bedingt. Ursächlich für einen Misserfolg können außerdem eine ungenügende Dichtigkeit und eine Infektion des Gefäßersatzes sein. Diese Arbeit beschäftigt sich mit der Weiterentwicklung einer "multifunktionellen“ Silikon–beschichteten und Medikamenten-freisetzenden Gefäßprothese, bei der die Oberflächeneigenschaften optimiert wurden. Material und Methoden Herstellung der Prothesen: Gewirkte Polyesterprothesen wurden maschinell mit Silikon beschichtet. Mit Hilfe einer neuen Beschichtungsmaschine wurden die Prothesen zusätzlich von innen mit Silikon betropft. Durch einen nass–chemischen Prozess wurden in einem zweiten Schritt verschiedene Stoffe kovalent an die Oberfläche des Silikons gebunden (Polyvinylpyrrolidon, Polyvinylalkohol, Phosphorylcholin, eine amphotere Oberfläche, Silber und die Kombination von Silber und PVA). Außerdem wurde das Medikament Paclitaxel (Taxol®) in die Silikonmatrix eingebracht. Untersuchung der Eigenschaften: Es wurde die Dichtigkeit nach Beschichtung und zusätzlich der Wasserverlust nach Einstich mit Kanülen und Venenverweilkanülen untersucht und mit dem herkömmlicher Prothesen verglichen (eine PTFE -, eine mit Kollagen beschichtete und eine 3-schichtige PTFE-Polymer – Prothese (Rapidax)). Zusätzlich wurden die antiinfektiösen Eigenschaften der verschiedenen Oberflächen (Silber, amphotere Oberfläche, Kollagen- und Silikon-beschichtete Polyesterprothesen) auf den Prothesen, der Einfluss der an die Prothese gebundenen Moleküle auf die Thrombogenität und die Elution von Paclitaxel, einem Medikament zur Unterdrückung der Intimahyperplasie, untersucht. Ergebnisse Herstellung der Prothesen. Die Umstellung des Beschichtungsvorgangs mit einer 3. Beschichtung von innen konnte realisiert werden. Untersuchung der Eigenschaften: Dichtigkeit: Bei der Untersuchung des Wasserverlustss nach Einstich von Kanülen und Venenverweilkanülen zeigten sich die geringsten Verlustraten bei der Rapidax®-Prothese und die höchsten bei der PTFE–Prothese. Die Silikon–beschichtete und die herkömmliche PET–Prothese erzielten insgesamt ähnliche Ergebnisse Oberflächenthrombogenität: Durch die Beschichtung mit Silikon konnte im Vergleich zur reinen Polyesterprothese und gegenüber den herkömmlichen Prothesen (Dacron®-Gelatine und PTFE) in allen Versuchen eine geringere Gerinnungsaktivierung für die Silikonprothese festgestellt werden. Die zusätzliche Oberflächenmodifizierung von Silikon- und Silberprothesen mit PVA erbrachte niedrigere Gerinnungswerte als die alleinigen Oberflächen. Die antiinfektiöse Oberfläche: Die mit Silber modifizierte Silikon-beschichtete Prothese konnte das bakterielle Wachstum komplett inhibieren. Die amphotere Oberfläche hingegen konnte das bakterielle Wachstum im Vergleich zur reinen Silikonoberfläche nur leicht hemmen. Medikamentenelution: Paclitaxel konnte im Kreislaufmodell und auch im statischen Versuchsaufbau über einen Zeitraum von bis zu 21 Tagen im Humanalbumin nachgewiesen werden. Diskussion Durch die Beschichtung mit Silikon wird eine primäre Dichtigkeit erreicht. Außerdem konnten nun die Prothesen durch die Umstellung des Herstellungsverfahrens in besserer Qualität und schneller hergestellt werden. Es konnte nachgewiesen werden, dass die Eigenschaften der einzelnen Moleküle in der Kombinationsprothese erhalten bleiben: so konnte die Thrombogenität der antiinfektiösen Silberprothese durch das PVA aufgehoben werden. Die Elution des Paclitaxels war unabhängig von der Oberflächenbeschichtung. Alternativ können auch andere Moleküle und Medikamente verwendet werden. Ziel ist nun die Testung dieser Prothese zunächst im Tierversuch und auf lange Sicht in einer klinischen Studie. Insbesondere bietet sich eine vergleichende Studie mit herkömmlichen Prothesen im Dialyseeinsatz an, da die Silikonprothese hinsichtlich der Dichtigkeit besonders bei Venenverweilkanülen mittleren Durchmessers gegenüber PTFE– und einer Polyester-Prothese überzeugen konnte. / Abstract Background: To replace affected blood vessels surgeons might use synthetic prostheses made of polytetraflourethylen (PTFE) and polyethylenterephtalat (PET, Polyester, Dacron®) instead of autologous veins. There are some common complications in conjunction with these prostheses. Major complications are infections, a deficient density, the thrombogenicity of the artificial surfaces and especially after reconstruction of smaller blood vessels the development of intima hyperplasia. The current dissertation describes the improvement of a "multifunctional" silicone-coated and drug-eluting vascular graft. Methods: Fabrication of prostheses: Knitted polyester-prostheses were coated with silicone. The former coating with silicone which was only from outside was completed with an extra coating at the inner side of the prosthesis. For this process we developed a special machine. The coating was followed by a modification with different molecules such as polyvinylpyrrolidone (PVP), polyvinylalcohole (PVA), phosphorylcholine (PC), an amphoteric surface, silver and a combination of silver and PVA. In another processes we inserted the drug paclitaxel in the matrix of the silicone. Analysis of characteristics: We analysed the density, the anti-infectious qualities of the prostheses, the influence of bonded molecules on the thrombogenicity and the drug-elution of paclitaxel. Density: We tested the average leakage and the leakage after puncture with canulas and indwelling venous catheters of the coated prostheses and three conventionally used vascular grafts (one PTFE, one collagen-coated and one prosthesis made of PTFE and another polymer (Rapidax)). Thrombogenicity of surfaces: We analysed the INR, Quick, PTT and fibrinogen after the contact of blood with the different surfaces. Furthermore we determined the amount of fibrinogen adhered platelets and platelet aggregates via FACS and the presence of coagulation activators (fragments of prothrombin F1+ F2) and of fibrinolysis (D-Dimeres) via ELISA (Enzyme-Linked Immunosorbend Assay). Infectivity: We analysed the effectivity of silver and of an amphotere surface on silicone catheters and on silicone prostheses against S. aureus. In an in-vitro experiment we incubated different catheters with a bacterial suspension and quantified the adherent bacteria. In a second experiment we incubated different coated prostheses with a S.aureus xen29 strain and determined the luminescence of the adhered bacteria. Drug elution: In static and dynamic experimental set-ups we detected the concentration of paclitaxel eluted from a prostheses via an Immuno-Assay (Fa. Cardax Pharmaceuticals, Hawaii, USA). This drug should inhibit the intima hyperplasia. Results: Production of prostheses: We realized the restructering of the coating process. Thereby we could save time and silicone. In addition we achieved a constant layer of silicone at the inside of the prostheses. Analysis of characteristics: Density: After puncturing the prostheses with canulas and indwelling venous catheters the Rapidax-prosthesis achieved the lowest and the PTFE the highest leakage. The silicone-coated and the collagen-coated prostheses achieved comparable results with advantages for the silicone-prosthesis. Thrombogenicity: The silicone-coated prostheses caused a lower activation of coagulation than the commonly used vascular grafts (Dacron-Gelatine or PTFE). The modification with PVA could additionally decrease the activation of silicone and silver. Infectivity: The silver-coated catheters and prostheses could completely inhibit the growth of bacteria. The highest growth was detected on the collagen-prostheses. The amphotere surface could achieve a low inhibation. Drug elution: It was possible to detect paclitaxel in the static as well as in the dynamic experimental set-up until the 21th day. Discussion: The coating with silicone could achieve a complete density of the prostheses. Furthermore we now have the ability to produce silicone-coated grafts in a better quality and in a shorter period of time. We could demonstrate that the individual characteristics of the different molecules persist in the combination with other molecules. The coating with PVA for example made it possible to compensate the higher activation of coagulation. Alternatively we could also coat the prostheses with other molecules or drugs. Our ambition is to test the silicone-prostheses in an animal experiment and in a clinical survey. Because of the good results in the density experiment it is conceivable to test our prostheses in conjunction with dialysis.

Tese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2008

Thesis --(MSc. (Medical Physics)), 2009. / Introduction The primary role of breast cancer treatment with radiation is to deliver a sufficient radiation dose to the cancer cells without unduly causing biological damage to the healthy tissues. For over 50 years, electron beam therapy has been an important modality for providing an accurate dose of radiation to superficial cancers and disease and for limiting the dose to underlying normal tissues and structures in particular to boost the dose to the tumour bed and surgical scars after mastectomy. The Monte Carlo code MCNP5 was used to determine the effect of silicone gel breast prosthesis on the electron beam dose distribution. Materials and Method Percentage depth dose curves (PDD) for 6, 9, 12, and 15 MeV electron energies along the electron central axis depth dose distributions in a water phantom and with silicone prosthesis immersed in a water phantom were simulated using MCNP5. In order to establish the accuracy of the MCNP5 code, the depth dose curves obtained using MCNP5 were compared against the measured depth dose curves obtained from the Varian 2100C linear accelerator. The simulated depth dose curves with silicone prosthesis immersed in water were compared to the measured depth dose curves with the vi silicone prosthesis in water. The dose at the interface of the prosthesis with water was measured using thermoluminiscent dosimeters. Results The simulated and measured depth dose curve and the investigated dosimetric parameters are within 2%. Simulations in the presence of silicone showed a decrease in dose as the at the interface as the beam passes from the prosthesis to water for most energies however, for 15 MeV beam there is an increase in dose at the interface between the prosthesis and water and this was verified by physical measurements. Conclusion There were good correlations between the measured and MCNP simulated depth dose curve. Differences were in order of 2%. Small deviations occurred due to the fact that the simulations assumed a monoenergetic beam that exits the accelerator head, while in the measured results the beam exiting from the accelerator head includes scatted radiation from the collimators and the applicator. The presence of the prosthesis does not perturb the electron beam central axis depth dose curve however, the 15 MeV beam enhanced the dose in front of the interface between the prosthesis and water. Despite the limitations mentioned above MCNP5 results agree reasonably with the measured results. Hence, MCNP5 can be very useful in simulating electron percentage depth dose data.

Due to the thesis embargo no abstract is provided.

Aachen, Techn. Hochsch., Thesis (doctoral), 2000.

Thesis (doctoral)--Freie Universität, Berlin, 2002.

No description available.