Em 1967, uma carta enviada ao British Medical Journal relatou que a re-esterilização em Óxido de Etileno (EO) do Cloreto de Polivinil (PVC) previamente gamairradiado forma grandes quantidades de etileno cloridrina, um composto altamente tóxico. Mesmo não apresentando dados mensurados, esta carta iniciou uma polêmica que até hoje divide a opinião de pesquisadores. Dirimir esta dúvida é relevante, uma vez que produtos de PVC esterilizados em Radiação Gama são habitualmente reesterilizados em EO em caso de vencimento do período de validade da esterilização, que é determinado pelo fabricante. Este estudo objetivou evidenciar a toxicidade de tubos de PVC por meio do teste de citotoxicidade pelo método da difusão em ágar em culturas celulares NCTC clone 929. Foram criados quatro grupos experimentais com 81 unidades de análise: G1, constituído de tubos in natura; G2 constituído de tubos esterilizados em Radiação Gama; G3 constituído de tubos esterilizados em EO e G4 constituído de tubos esterilizados em Raios Gama e re-esterilizados em Óxido de Etileno. Os testes foram realizados em triplicata e cada tubo foi testado de forma a representar as superfícies internas, externas e massa. Após a mensuração do halo incolor, as unidades de análise foram graduadas de acordo com os graus de reatividade biológica descritos na norma ISO 10993-5:2009. Foram consideradas citotóxicas apenas as unidades análise que obtiveram grau três ou acima. Os resultados revelaram toxicidade celular apenas no grupo G3, no qual foram observadas placas com morte de todas as células, fato que demandou repetições, conforme a metodologia adotada. Na primeira repetição houve persistência de unidades de análise capazes de causar a morte de todas as células da placa. Na segunda repetição, nenhuma unidade de análise foi classificada como citotóxica. Inferiu-se que houve falhas no processo de aeração no grupo G3 e na primeira repetição. O resultado da cromatografia gasosa dos grupos G3 e G4 atestou que os materiais de ambos os grupos estariam seguros para uso. O valor máximo dos resíduos encontrados em ambos os grupos foi idêntico, contradizendo os resultados do teste de citotoxicidade. Concluiu-se que, nas condições deste experimento, os materiais de PVC esterilizados em Radiação Gama e, consecutivamente, reesterilizados em EO não são citotóxicos e a cromatografia gasosa, utilizada isoladamente, pode produzir resultados questionáveis quanto à segurança dos materiais esterilizados em EO. / In 1967, a letter sent to the British Medical Journal reported that the re-sterilization with Ethylene Oxide (EtO) of previously irradiated Polyvinyl Chloride (PVC) formed large amounts of ethylene chlorohydrin, a highly toxic compound. Even though it did not present measured data, this letter initiated a controversy that still divide the opinion of researchers to date. To solve this doubt is relevant, as PVC products submitted to gamma radiation are usually re-sterilized with EtO, when the sterilization validity has expired, which is determined by the manufacturer. The present study aimed at assessing the toxicity of PVC tubes through the cytotoxicity test, using the NCTC clone 929 cell culture agar diffusion test. Four experimental groups were created with 81 analysis units: G1, consisting of tubes in natura; G2, consisting of tubes submitted to gamma radiation; G3, consisting of tubes submitted to EtO sterilization and G4, consisting of tubes submitted to gamma-radiation and re-sterilized with EtO. The tests were carried out in triplicate and each tube was tested in order to represent its internal and external surfaces, as well as its mass. After the measurement of the colorless halo, the analysis units were graded according to the degrees of biological reactivity described in the ISO 10993-5:2009. Only the analysis units that were considered grade 3 and above were considered cytotoxic. The results showed evidence of cell toxicity only in G3, which disclosed plaques that presented death of all cells, a fact that necessitated repetition of the experiment, according to the adopted methodology. The first repetition showed the persistence of the analysis units to cause the death of all cells in the plaque. At the second repetition, none of the analysis units was classified as being cytotoxic. It was inferred that there were failures in the process of aeration in group G3 and in the first repetition. The results of the gas chromatography of groups G3 and G4 demonstrated that the materials from both groups would be safe for use. The maximum value of residues found in both groups was identical, in disagreement with the cytotoxicity test results. It was concluded that, according to the conditions of this experiment, the PVC materials submitted to gamma-radiation and consecutively sterilized by EtO are not cytotoxic and that the gas chromatography, when used alone, can yield debatable results regarding the safety of materials sterilized with EtO.

Made available in DSpace on 2014-12-17T15:42:03Z (GMT). No. of bitstreams: 1 CyprianoGTN.pdf: 2726336 bytes, checksum: 398151afa4a714a39af458b59a347ead (MD5) Previous issue date: 2008-05-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Two methodologies were proposed to obtain micro and macroporous chitosan membranes, using two different porogenic agents. The methodologies proved to be effective in control the porosity as well as the pore size. Thus, microporous membranes were obtained through the physical blend of chitosan and polyethylene oxide (PEO) on an 80:20 (m/m) ratio, respectively, followed by the partial PEO solubilization in water at 80 ◦C. Macroporous chitosan membranes with asymmetric morphology were obtained using SiO2 as the porogenic agent. In this case, chiotsan-silica ratios used were 1:1, 1:3 and 1:5 (m/m). Membranes characterization were carried out by SEM (scanning electronic microscopy), X-ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR), Thermal analysis (TG, DTG , DSC and DMTA). Permeability studies were performed using two model drugs: sodium sulfamerazine and sulfametoxipyridazine. By transmission FTIR it was possible to confirm the complete removal of SiO2. The SEM images confirmed the porous formation for both micro and macroporous membranes and also determined their respective sizes. By thermal analysis it was possible to show differences related with water sorption capacity as well as thermal stability for both membranes. DTG and DSC allowed evidencing the PEO presence on microporous membranes. The absorbance x time curves obtained on permeability tests for micro and macroporous membranes showed a linear behavior for both drugs in all range of concentration used. It was also observed, through P versus C curves, an increase in permeability of macroporous membranes according to the increase in porosity and also a decrease on P with increase in drug concentration. The influences of the drug molecular structure, as well as test temperatures were also evaluated / Duas metodologias foram propostas para a obten??o de membranas macro e microporosas de quitosana, utilizando dois diferentes agentes formadores de poros. As metodologias mostraram-se eficientes no controle da porosidade e do tamanho dos poros gerados. Deste modo, membranas microporosas foram obtidas atrav?s de mistura f?sica da quitosana com o poli(?xido de etileno) (PEO), na propor??o 80:20 (m/m), respectivamente, seguido da solubiliza??o parcial do PEO em ?gua a 80 ◦C, e membranas macroporosas de quitosana com morfologia assim?trica foram obtidas utilizando um agente inorg?nico gerador de poros (SiO2). Neste caso, as propor??es quitosana-s?lica utilizadas foram 1:1, 1:3 e 1:5 (m/m). A caracteriza??o das membranas foi realizada atrav?s de microscopia eletr?nica de varredura (MEV), difra??o de raios X (DRX), espectroscopia de absor??o na regi?o do infravermelho (FTIR), an?lise t?rmica (TG, DTG, DSC e DMTA) e do estudo de sua permeabilidade utilizando-se dois f?rmacos modelos (sulfamerazina de s?dio e sulfametoxipiridazina). Atrav?s da t?cnica de FTIR em pastilha de KBr foi poss?vel confirmar, nas membranas macroporosas, a retirada completa do gerador de poros (SiO2). As imagens obtidas com o MEV confirmam a forma??o dos poros, tanto para as microporosas quanto para as macroporosas e determinam os seus respectivos tamanhos. Atrav?s das an?lises de TG, DTG e DSC foi poss?vel mostrar as diferen?as na capacidade de reten??o de ?gua para todas as membranas e suas estabilidades t?rmicas. As an?lises de DTG e DSC permitiram tamb?m evidenciar a presen?a de PEO nas membranas microporosas. As curvas Absorb?ncia ? Tempo obtidas a partir dos ensaios de permeabilidade, para as membranas micro e macroporosas, apresentaram um comportamento linear para ambos os f?rmacos e em todas as concentra??es utilizadas. Foi observado tamb?m, atrav?s da curva P ? C, um aumento na permeabilidade das membranas de acordo com o aumento da porosidade, bem como uma diminui??o desta com o aumento da concentra??o (C) dos f?rmacos modelo. Fatores tais como a influ?ncia da estrutura do f?rmaco e o efeito da temperatura tamb?m foram avaliados

The aim of this thesis work is to study the physico-chemical properties of poly(ethylene oxide), PEO, based brush polymers both in solution and at solid/aqueous interfaces. The importance of studying the surface properties of brush polymers can be related to a broad spectrum of interfacial-related applications such as colloidal stability, lubrication, detergency, protein repellency to name a few. In many applications it is desirable to form brush-like structures through simple physisorption. In this context the surface properties of PEO based brush polymers differing in molecular architecture were studied, using ellipsometry and surface force apparatus (SFA), to gain some understanding regarding the effect of molecular architecture on the formation of brush structures. The molecular architecture was varied by varying the charge/PEO ratio along the backbone. This study demonstrates that the formation of a brush structure at solid/aqueous interface is due to interplay between the attraction of the backbone to the surface and the repulsions between the PEO side chains. An optimal balance between the two antagonistic factors is required if one aims to build a well-defined brush structure at the interface. In this study the brush-like structures are formed when 25-50% of the backbone segments carry poly(ethylene oxide) side chains. Scattering techniques such as light and neutron reveal that these brush polymers are stiff-rods up to a charge to PEO ratio of 75:25. These stiff PEO brush polymer easily replace the more flexible linear PEO at the silica/water interface, the reason being that the entropy loss on adsorption is smaller for the brush polymer due to its stiff nature.  Polymer-surfactant systems play a ubiquitous role in many technical formulations. It is well known that linear PEO, which adopts random coil conformation in aqueous solution, interact strongly with the anionic surfactant, Sodium Dodecyl Sulphate (SDS). It is of interest to study the interaction between SDS and brush PEO owing to the fact that the PEO side chains have limited flexibility as compared to the linear PEO.  The interaction between brush PEO and the anionic surfactant SDS in solution are studied using different techniques such as NMR, tensiometry, SANS and light scattering. The main finding of this study is that the interaction is weaker compared to the linear PEO-SDS interactions which poses an interesting question regarding the role of chain flexibility in polymer-surfactant interactions. / QC 20100813

Ce travail a permis de démontrer que l’électrofilage, ainsi que l’électronébulisation, sont des méthodes faciles et efficaces de préparation de complexes entre des polymères et des petites molécules. En effet, la plupart des méthodes de préparation de complexes donnent des mélanges inhomogènes à cause de la cristallisation cinétiquement favorisée des petites molécules. Or, un mélange inhomogène peut être très difficile à caractériser. Dans ce travail, l’électrofilage a été utilisé pour la première fois avec succès pour obtenir des nanofils de complexe entre le poly(oxyde d’éthylène) (PEO) et le NaSCN (PEO-NaSCN) ainsi qu’entre le PEO et l’hydroquinone. L’électronébulisation a été utilisée pour obtenir du complexe entre la polycaprolactone (PCL) et l’urée. L’électrofilage n’était pas possible pour le système PCL-urée parce que la solubilité n’était pas suffisante pour atteindre la viscosité minimale requise pour l’électrofilage. L’électronébulisation peut donc complémenter l’électrofilage et rendre la technique applicable à encore plus de systèmes. Les systèmes ont été caractérisés par spectroscopie infrarouge (FT-IR), par diffraction de rayons X (XRD), par calorimétrie différentielle à balayage (DSC) et par microscopies optique et électronique à balayage. / This work has allowed to show that electrospinning, as well as electrospraying, are easy and efficient methods for preparing complexes between polymers and small molecules. Most complex preparation methods yield inhomogeneous mixtures because of the kinetically favoured crystallization of small molecules. An inhomogeneous mixture can be very difficult to characterize. In this work, electrospinning was used for the first time to obtain nanofibres of complexes between poly(ethylene oxide) (PEO) and NaSCN (PEO-NaSCN) as well as between PEO and hydroquinone. Electrospraying was used to obtain a complex between polycaprolactone (PCL) and urea. Electrospinning was not possible for the PCL-urea system because the solubility was not sufficient to attain the minimal viscosity required for electrospinning. Electrospraying can thus be used as a complementary technique to electrospinning, making this approach applicable to a much wider range of systems. The systems were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and microscopy (optical and scanning electronic microscopy).

In the present work, we have undertaken a structural study of PS-b-PEO single crystals to elucidate the influence of the state of the PS block on crystallization from dilute solution and on subsequent thermal annealing at elevated temperature. It is noteworthy that the interest in these systems has been recently renewed in the perspective of using them as a model of grafted amorphous brushes with variable grafting density. Indeed, during crystallization of PEO, the amorphous block, i.e. PS, is rejected from the crystal accumulating on its basal surfaces. Since the crystal thickness formed during isothermal crystallization is a sharply selected value, the grafting density of the resulting PS brush is also well defined. Therefore by varying the crystal thickness one can obtain the PS brushes with grafting density varying in a broad range.In our study, a combination of reciprocal and direct-space techniques such as SAXS/WAXS and AFM was employed. While AFM experiments were performed on isolated single crystals, the SAXS investigation was carried out on oriented mats of single crystals slowly sedimented from the "mother" solution. In this case, the one-dimensional two-phase system model was used for the data interpretation where the thickness of the amorphous (La) and crystalline (Lc) layers are conventionally determined following the correlation fonction and interface distribution fonction approaches.

Em 1967, uma carta enviada ao British Medical Journal relatou que a re-esterilização em Óxido de Etileno (EO) do Cloreto de Polivinil (PVC) previamente gamairradiado forma grandes quantidades de etileno cloridrina, um composto altamente tóxico. Mesmo não apresentando dados mensurados, esta carta iniciou uma polêmica que até hoje divide a opinião de pesquisadores. Dirimir esta dúvida é relevante, uma vez que produtos de PVC esterilizados em Radiação Gama são habitualmente reesterilizados em EO em caso de vencimento do período de validade da esterilização, que é determinado pelo fabricante. Este estudo objetivou evidenciar a toxicidade de tubos de PVC por meio do teste de citotoxicidade pelo método da difusão em ágar em culturas celulares NCTC clone 929. Foram criados quatro grupos experimentais com 81 unidades de análise: G1, constituído de tubos in natura; G2 constituído de tubos esterilizados em Radiação Gama; G3 constituído de tubos esterilizados em EO e G4 constituído de tubos esterilizados em Raios Gama e re-esterilizados em Óxido de Etileno. Os testes foram realizados em triplicata e cada tubo foi testado de forma a representar as superfícies internas, externas e massa. Após a mensuração do halo incolor, as unidades de análise foram graduadas de acordo com os graus de reatividade biológica descritos na norma ISO 10993-5:2009. Foram consideradas citotóxicas apenas as unidades análise que obtiveram grau três ou acima. Os resultados revelaram toxicidade celular apenas no grupo G3, no qual foram observadas placas com morte de todas as células, fato que demandou repetições, conforme a metodologia adotada. Na primeira repetição houve persistência de unidades de análise capazes de causar a morte de todas as células da placa. Na segunda repetição, nenhuma unidade de análise foi classificada como citotóxica. Inferiu-se que houve falhas no processo de aeração no grupo G3 e na primeira repetição. O resultado da cromatografia gasosa dos grupos G3 e G4 atestou que os materiais de ambos os grupos estariam seguros para uso. O valor máximo dos resíduos encontrados em ambos os grupos foi idêntico, contradizendo os resultados do teste de citotoxicidade. Concluiu-se que, nas condições deste experimento, os materiais de PVC esterilizados em Radiação Gama e, consecutivamente, reesterilizados em EO não são citotóxicos e a cromatografia gasosa, utilizada isoladamente, pode produzir resultados questionáveis quanto à segurança dos materiais esterilizados em EO. / In 1967, a letter sent to the British Medical Journal reported that the re-sterilization with Ethylene Oxide (EtO) of previously irradiated Polyvinyl Chloride (PVC) formed large amounts of ethylene chlorohydrin, a highly toxic compound. Even though it did not present measured data, this letter initiated a controversy that still divide the opinion of researchers to date. To solve this doubt is relevant, as PVC products submitted to gamma radiation are usually re-sterilized with EtO, when the sterilization validity has expired, which is determined by the manufacturer. The present study aimed at assessing the toxicity of PVC tubes through the cytotoxicity test, using the NCTC clone 929 cell culture agar diffusion test. Four experimental groups were created with 81 analysis units: G1, consisting of tubes in natura; G2, consisting of tubes submitted to gamma radiation; G3, consisting of tubes submitted to EtO sterilization and G4, consisting of tubes submitted to gamma-radiation and re-sterilized with EtO. The tests were carried out in triplicate and each tube was tested in order to represent its internal and external surfaces, as well as its mass. After the measurement of the colorless halo, the analysis units were graded according to the degrees of biological reactivity described in the ISO 10993-5:2009. Only the analysis units that were considered grade 3 and above were considered cytotoxic. The results showed evidence of cell toxicity only in G3, which disclosed plaques that presented death of all cells, a fact that necessitated repetition of the experiment, according to the adopted methodology. The first repetition showed the persistence of the analysis units to cause the death of all cells in the plaque. At the second repetition, none of the analysis units was classified as being cytotoxic. It was inferred that there were failures in the process of aeration in group G3 and in the first repetition. The results of the gas chromatography of groups G3 and G4 demonstrated that the materials from both groups would be safe for use. The maximum value of residues found in both groups was identical, in disagreement with the cytotoxicity test results. It was concluded that, according to the conditions of this experiment, the PVC materials submitted to gamma-radiation and consecutively sterilized by EtO are not cytotoxic and that the gas chromatography, when used alone, can yield debatable results regarding the safety of materials sterilized with EtO.

O presente estudo analisou 275 resultados de resíduos de óxido de etileno (OE) e subprodutos tais como etilenoglicol (ETG) e etilenocloridrina (ETCH), em produtos médicos esterilizados com óxido de etileno. A metodologia utilizada difere de outros estudos por não ser uma simulação, mas sim casos reais de produtos esterilizados nos quais se mediu a quantidade de resíduos. As quantidades de resíduos obtidas foram comparadas com os limites máximos estabelecidos por normas. Observou-se uma grande adequação dos resultados aos limites estabelecidos por norma. No entanto problemas foram encontrados, principalmente, na grande quantidade de valores aberrantes, problema este que indica possíveis problemas na fase de aeração dos produtos. Para a fundamentação do presente estudo foram feitos estudos complementares, aqui apresentados com os nomes de: Análise de Incertezas em Curvas de Calibração de um Cromatógrafo na Medição de Resíduos de Óxido de Etileno; Resíduos de Óxido de Etileno em Esponja Cirúrgica Gelfoam® e Resíduos de Óxido de Etileno em Soro Fisiológico 0,9%. / The present study analyzed 275 results for residues of ethylene oxide (ETO) and by-products such as ethylene glycol (ETG) and ethylene chloridrine (ETCH), in medical devices sterilized using ethylene oxide. The methodology differs from other studies for not being a simulation, but rather real cases of sterilized devices in which the amount of residue was measured. The quantities of residues obtained were compared with the top levels established by regulations. There was a great adjustment of the results to the limits established by the regulation. However problems were found mainly in the large amount of outliers values, a problem that indicates possible issues during the airing stage of the devices. In order to support this study, related studies have been made and are presented here with the names: Analysis of Uncertainty in Chromatograph Calibration Curves in Ethylene Oxide Residues Measuring; Ethylene Oxide Residuals in Gelfoam® and Ethylene Oxide Residuals in Saline Bottles.

Este trabalho apresenta um estudo sobre a síntese e propriedades do copolímero poli(l,l-lactídeo-stat-e-caprolactona)-bloco-poli(óxido de etileno)-bloco-poli(l,l-lactideostat-e-caprolactona). Poli(óxido de etileno) de massa molar 20.000 u.m.a. e poli(óxido de etileno) modificado, preparado a partir de poli(glicol etilênico) de massa molar 4.000 u.m.a., foram selecionados para o processo da síntese. A reação foi feita pela polimerização por abertura de anel em massa a 120ºC usando octoanato de estanho como iniciador. A composição química de cada amostra foi determinada com auxílio de RMN-1H e RMN-13C e suas propriedades mecânicas foram verificadas e comparadas utilizando análises térmicas como DMTA, DSC, TG e a aplicação da MEV como análise complementar. A observação pelas fotos de MOLP permitiu a visualização do comportamento de nucleação dos copolímeros e as características de sua cristalinidade. Seu grau de cristalinidade e as fases cristalinas foram identificados por difração de raios X (WAXS). A biocompatibilidade do material também foi examinada pela cultura de células. Os resultados de caracterização indicam o sucesso da copolimerização, as propriedades elastoméricas e, sua não citotoxidade comprovaram a possibilidade do uso destes copolímeros como biomateriais. Contudo, o tempo prolongado de reação e baixa incorporação do monômero lactídeo ainda são questões a serem melhoradas para a viabilização do copolímero como material de implante na área biomédica. / This work includes the study of the synthesis and characterization of the copolymer poly(l,l-lactide-stat-e-caprolactone)-b-PEG-b-poly(l,l-lactide-stat-e-caprolactone). Poly (ethylene oxide) with molar weight 20.000 and poly(ethylene oxide) modified, prepared from poly(ethylene oxide) with molar weight 4000 have been selected for this synthesis process. The reaction was done by ring-opening bulk polymerization, using stannous octoate as initiator at 120ºC. The chemical composition of samples were determined by 1H-NMR and 13C-NMR and their mechanical properties were verified using thermal analyses like DMTA, DSC and TG. Scanning electron microscopy (SEM) was applied as a complementary analysis. The pictures of polarizing optical microscopy showed us the copolymer\'s nucleation behaviors and their respective crystallization. The degrees of crystallinity and phase of copolymers were determined by WAXS. The biocompatibility of the copolymer was examined by cell cultivation test. The result of these analyses above indicated the success of synthesis. Their rubbery properties and non-toxicity allowed their application as biomaterial. However, the long reaction time and low incorporation of monomer of lactide might to be improved to increase its potential use in biomedical area in the future.

Estima-se que há mais de 50 anos, as furadeiras elétricas (FE) têm sido empregadas em cirurgias ortopédicas nos hospitais brasileiros para a perfuração óssea. Trata-se de equipamento elétrico, termossensível, não indicado para uso cirúrgico, não avaliado anteriormente quanto à eficácia da esterilização, suspeitando-se de risco potencial para infecções do sítio cirúrgico ou relacionadas a próteses ortopédicas. Os objetivos desse estudo foram: avaliar a carga microbiana de FE do uso cirúrgico e avaliar a eficácia da esterilização por óxido de etileno (ETO) de FE novas intencionalmente contaminadas. Trata-se de pesquisa experimental, laboratorial, randomizada e aplicada desenvolvida no laboratório de pesquisas experimentais da Escola de Enfermagem da Universidade de São Paulo. O trabalho foi realizado em duas fases. As condições assépticas foram rigorosamente seguidas para o controle das variáveis. Quinze FE analisadas na fase I, tiveram distribuição aleatória e cega, capturadas em um centro cirúrgico de um hospital escola. Foram cultivados: o ar gerado pelo motor e alíquotas de 10 µL do lavado das superfícies interna e externa das FE. Ainda nessa fase foi realizado um controle positivo onde uma FE foi contaminada com Serratia marcescens e um teste do método de filtração por membrana de porosidade de 0,45 µm com uma FE limpa, onde as membranas que filtraram diferentes quantidades do lavado foram cultivadas. Na fase II foram analisadas 22 FE e três perfuradores de osso (PO). Dezesseis FE constituíram o grupo experimental (GE), seis o controle positivo (GCP) e três PO constituíram o controle negativo (GCN). Todos os equipamentos previamente limpos e esterilizados foram submetidos à contaminação com esporos de Bacillus atrophaeus. As FE do GCP foram analisadas após a exposição ao contaminante, furadeiras do GE e perfuradores do GCN foram submetidos à limpeza e esterilização por ETO antes de serem analisados. Foram cultivados: ar gerado pelo motor e membrana filtrante após a filtração do lavado das superfícies interna e externa dos equipamentos. Foram realizadas coloração e microscopia: Gram para culturas positivas; Wirtz-Conklin para culturas positivas com bacilos Gram positivos. Os resultados mostraram que a carga microbiana de FE do uso cirúrgico é baixa e foi detectada em duas ocasiões no cultivo do ar, 1 ufc/FE e em uma ocasião no cultivo de alíquotas do lavado, 9 ufc/FE. O controle positivo realizado com Serratia marcescens comprovou a sensibilidade do método para amostras contendo alta concentração de contaminantes. O método filtração por membrana mostrou-se sensível para detectar baixa contaminação das FE, sendo o eleito para o teste de esterilidade. Os controles positivos apresentaram crescimento do microrganismo contaminante, comprovando a aderência ao material. Os controles negativos não apresentaram crescimento. Das 16 FE do GE, duas apresentaram crescimento sendo cada uma delas de 1ufc do contaminante inicial respectivamente no cultivo do ar e no cultivo da membrana. Foi comprovada a eficiência de 99,99999881% do processo de esterilização por ETO, com a probabilidade de sobrevivência de 1,19 x 10-8. Nas condições do desenvolvimento do experimento, a eficácia da esterilização das FE por ETO foi comprovada / Electric drills have been used to perform orthopedic surgeries in Brazilian hospitals for almost more than 50 years. This electric equipment is heat-sensitive and it is not appropriate to use in surgical procedures. Until now the efficacy of sterilization of this item had been not evaluated as a potential risk for the occurrence of surgical site infection or infection related to orthopedic prosthesis. The objectives of this study were to evaluate the bioburden of the used electric drills and to evaluate the sterility of the new electric drills contaminated artificially. It is an experimental and randomized study performed in the research laboratory of the Nursing School of the São Paulo University. The study was performed in two phases following rigorous aseptic techniques to control the variables. In the first phase fifteen electric drills were taken in the operating room of the university hospital and included in the study using aleatory and blind methods. Cultures were performed from the air produced by the drill engine and the aliquots of 10µL of the rinsed water from the internal and external surface of the electric drill. One electric drill was included as a positive control and was contaminated with Serratia marcescens. A membrane filter with porous of 0,45 µm were cultured after had been exposed to the rinsed water from the internal and external surface of the clean electric drill. In the second phase were analyzed twenty two electric drills and three orthopedic drilling machines. Sixteen electric drills were included in the experimental group, six were the positive control group and three orthopedic drilling machines in the negative control group. All the equipments previously cleaned and sterilized were submitted to the contamination with Bacillus atrophaeus. The electric drills included in the positive control group were analyzed after exposed to the contaminant and the electric drills of the experimental group and orthopedic drills included in the negative control group were submitted to clean and ethylene oxide sterilization before to start the analysis. The air produced by the drill engine and the membrane filter after exposed to the rinsed water of the internal and external surface of the electric drill were cultured. It was performed Gram microscopy and Wirtz-Conklin to Gram positive bacilli. The results showed low bioburden in the electric drills in two episodes. So, 1 cfu/electric drill was found in one episode of the air culture and 9 cfu/electric drill in one episode of culture of the aliquot. The positive control with Serratia marcescens demonstrated the sensibility of the method in samples with high concentration of contaminants. The method of membrane filtration showed sensible to detect low bioburden of the electric drills. So it is elected for the sterility test. The positive controls showed the growth of the contaminant microrganism demonstrating the adherence to the material surface. The negative controls did not show growth. Two of the sixteen electric drills included in the experimental group showed each one growth of 1cfu of the initial contaminant of the air and the membrane cultures respectively. So the efficiency of the sterilization process was 99,99999881% and the probability of find survivor was 1,19 x 10-8. In these conditions the study demonstrates that the efficacy of the ethylene oxide sterilization was proved

L’objectif de cette étude est la réalisation de séparateurs de batterie haute performance par extrusion. Ces électrolytes polymères solides nécessitent d’être perméables au courant ionique mais aussi isolants électrique, tout en étant résistants mécaniquement. Une des possibilités étudiée pour le renfort mécanique est la dispersion de charges nanométriques (whiskers de cellulose) dans un polymère. Les whiskers de cellulose sont des bâtonnets cristallins d’une longueur entre 100 et 300nm et d’un diamètre entre 5 et 20 nm. Lorsque ces charges sont dispersées de façon homogène, elles forment un réseau percolant, améliorant de cette façon le renfort mécanique de la matrice pour de faibles concentrations. Le but est donc de réaliser cette dispersion dans un polymère fondu par extrusion, en comparaison avec le procédé bien établi d’évaporation de solvant. Les difficultés principales viennent de l’agglomération des whiskers de cellulose via des liaisons hydrogènes et du milieu très concentré dans lequel ces charges doivent être dispersées. Ainsi, la première partie de l’étude est de déterminer le processus de préparation des whiskers de cellulose, limitant l'agglomération et permettant d’obtenir une suspension stable. Ce système stable est nécessaire pour la formation d'un réseau par évaporation de solvant. Une fois le protocole optimisé, la deuxième partie de l’étude porte sur la dispersion de ces whiskers dans la matrice fondue au mélangeur interne et en extrusion. Les mélanges et films obtenus sont caractérisés par analyse en rhéologie dynamique, analyse thermique et analyse mécanique. Une dégradation de la matrice ainsi qu’une orientation des whiskers sont observées. Pour contourner ces contraintes, plusieurs alternatives sont utilisées. La première consiste à adsorber un copolymère sur les whiskers ; cette méthode augmente l’effet hydrodynamique mais aucun réseau n’est obtenu. La deuxième alternative est l’utilisation d’un polymère de faible masse molaire, permettant de diminuer la viscosité du mélange et par conséquent de limiter l’orientation des charges. Cette voie permet la formation d’un réseau percolant, tout en évitant la dégradation de la matrice dans l’extrudeuse. La troisième alternative utilise un copolymère de faible masse molaire synthétisé à partir d’un monomère porteur de doubles liaisons. La faible masse molaire permet de diminuer la cristallinité du séparateur et donc d’améliorer les performances ioniques à basse température. Les doubles liaisons permettent une réticulation assurant la tenue mécanique du film / The aim of this study is to produce high-performance battery separators through extrusion. These solid polymer electrolytes should be permeable to ionic current but electrically insulating, all the while maintaining sufficient mechanical resistance. To this end, the dispersion of nanometrics fillers (cellulose whiskers) in a polymer is studied. Cellulose whiskers are crystalline sticks, with a length between 100 and 300 nm and a diameter between 5 and 20 nm. It is well known that a homogeneous dispersion of these fillers allows a percolating network, improving the mechanical reinforcement of the matrix at low concentrations. The goal is to carry out this dispersion in molten polymer through extrusion, as opposed to the well-established solvent evaporation process. The main difficulties are the aggregation of cellulose whiskers which occurs through hydrogen bonding and the concentrated medium in which these fillers are dispersed. The first part of the study is to determine the optimum process to prepare cellulose whiskers in order to limit aggregation and thus obtain a stable aqueous suspension. This stable system is necessary to obtain a percolating network in the polymer matrix through solvent evaporation. Once the protocol optimised, the second part of the study focuses on the dispersion of these whiskers in the molten matrix using both the internal mixer and the extruder. Blends and films are characterized by dynamical rheology analysis, thermal analysis and mechanical analysis: a degradation of the matrix and an orientation of the whiskers are observed. To by-pass these issues, several alternatives are used. The first one involves the adsorption of a copolymer on the whiskers. This method increases the hydrodynamic effect; however no percolation network is obtained. The second alternative is to use a low molar mass polymer. This leads to a decreased polymer viscosity which limits the orientation of the fillers, allowing the percolating network to form and prevents polymer degradation. The third way uses a copolymer with a low mass molar, synthesized from a monomer which carries double bonds. The low molar mass allows the decrease of the separator crystallinity thus improving the ionic performances at low temperatures. The double bonds can crosslink under UV light, which enhances the mechanical strength of the film