In the diploma thesis with the above name, I have described the subject in general in the introductory part. The diploma thesis describes ionizing radiation, history and present, its types and uses as well as protective aids, which are necessary to use when working with ionizing radiation. I have dealt with the principle of monitoring workers, workplaces and patients, as well as limitations and all the quantities that describe or characterize ionizing radiation. In the next part of my diploma thesis I focused on dosimetry, where I described types of dosimeters. The diploma thesis deals with legislation - laws, decrees and government orders, which give the legal framework of the given issue. In the final part of this thesis I have described the radiodiagnostic activity in the Department of Digital Subtraction Angiography, Gastroenterology and Interventional Cardiology, Pilsen University Hospital, from whose activities I drew background material for this work. The aim of this diploma thesis was to find out the measured values of doses of ionizing radiation in the medical staff and to analyze the radiation protection provision at the Department of Radiology at FN Pilsen. For comparison, the measured values from the personal dosimeters of the medical staff at the mentioned workplaces at FN Plzeň were used. In the theoretical part I used all available sources, foreign and Czech literature. Resources are provided at the end of this paper. The work is focused on quantitative research, which I used in the practical part with statistics. All obtained values from personal dosimeters were obtained from the records of the University Hospital in Pilsen. The data presented in the diploma thesis are measured doses of healthcare personnel for the last seven years. Doses were measured using OSL dosimeters, which are today the most widely used dosimetry in health care. The main aim of the thesis, given that I work as a radiological assistant, was the examination of the doses of radiological assistants, doctors and nurses in the Department of Radiology of the Faculty of Nursing in Pilsen, not in the patients who were examined in these departments. In terms of patients, this is a medical exposure, and in this case there is no limit for irradiation.

Les modifications post-traductionnelles des protéines de réparation de l’ADN et des facteurs chromatiniens par poly(ADP-ribose)ylation et par phosphorylation sont essentielles pour le maintien de l’intégrité de l’ADN et de la chromatine, en particulier dans la réponse cellulaire aux dommages de l’ADN induits par radiation ionisantes (RI). Parmi les protéines impliquées dans ces deux processus nous trouvons, respectivement, la poly(ADP-ribose) polymérase-1 (PARP-1) et PARP-2, et la kinase dépendante des cyclines Cdk5 : PARP-1 et PARP-2 sont impliqué dans le mécanisme de réparationdes cassures simples brin (CSBs) de l’ADN (Single Strand Break Repair : SSBR ) et la déplétion de Cdk5 a été liée à l’augmentation de la sensibilité des cellules aux inhibiteurs de PARPs. Nous avons montré, en utilisant des cellules HeLa stablement déplété pour Cdk5 ou PARP-2, que ces deux protéines sont impliquées dans les deux sous-voies du SSBR, le short- (SPR) et le long-patch repair (LPR). L’absence de Cdk5 ou PARP-2 entraîne des modifications du fonctionnement du SSBR, notamment en termes de recrutement des protéines de réparation PARP-1 et XRCC1, impliquées dans le SPR, et PCNA, protéine clé du LPR, au site du photo-dommage. PARP-2 et Cdk5 agissent aussi sur la balance du niveau des poly(ADP-ribose) car en absence de Cdk5 une hyper-activation de PARP-1 a été montrée, et en absence de PARP-2 une diminution de l’activité de la protéine poly(ADP-ribose) glycohydrolase (PARG) a été aussi observée. Cependant, malgré ces changements les deux lignées cellulaires dépourvues de Cdk5 (Cdk5KD) ou de PARP-2 (PARP-2KD) réparent de façon normale les CSBs radio-induites, mais, intéressement et contrairement aux cellules PARP-2KD, les cellules Cdk5KDsont sensibles à l’effet létal des RI. De plus nous avons montré que Cdk5, PARP-2 et PARG sont toutes les trois impliquées dans la régulation du recrutement et de dissociation du facteur chromatinien ALC1 suggérant leur implication dans la régulation de la dynamique de la chromatine en réponse aux photo-dommages de l’ADN. Ces résultats avec l’observation de la diminution du recrutement de PARP-1 dans les cellules Cdk5KD et PARP-2KD, montrent l’apparition d’un réseau complexe de phosphorylation et de poly(ADP-ribose)ylation en réponse aux RI qui implique Cdk5 , PARP-1,PARP-2 and PARG et qui est fort probablement initié par l’activité kinase de Cdk5. / The post-translational modifications of DNA repair proteins and histone remodeling factors by poly(ADP-ribose)ylation and phosphorylation are essential for the maintenance of DNA integrity and chromatin structure, and in particular in response to DNA damaging produced by ionizing radiation (IR). Amongst the proteins implicated in these two processes are the poly(ADP-ribose) polymerase -1 (PARP-1) and PARP-2, and the cyclin-dependent kinase Cdk5: PARP-1 and 2 are involved in DNA single strand break (SSB) repair (SSBR) and Cdk5 depletion has been linked with increased cell sensitivity to PARP inhibition. We have shown by using HeLa cells stably depleted for either CdK5 or PARP-2, that the recruitment profile of PARP-1 and XRCC-1, two proteins involved in the short-patch (SP) SSBR sub-pathway, to DNA damage sites is sub-maximal and that of PCNA, a protein involved in the long-patch (LP) repair pathway, is increased in the absence of Cdk5 and decreased in the absence of PARP-2 suggesting that both Cdk5 and PARP-2 are involved in both SSBR sub-pathways.PARP-2 and Cdk5 also impact on the poly(ADP-ribose) levels in cells as in the absence of Cdk5 a hyper-activation of PARP-1 was found and in the absence of PARP-2 a reduction in poly(ADP-ribose) glycohydrolase (PARG) activity was seen. However, in spite of these changes no impact on the repair of SSBs induced by IR was seen in either the Cdk5 or PARP-2 depleted cells (Cdk5KD or PARP-2KD cells) but, interestingly, increased radiation sensitivity in terms of cell killing was noted in the Cdk5 depleted cells. We also found that Cdk5, PARP-2 and PARG were all implicated in the regulation ofthe recruitment and the dissociation of the chromatin-remodeling factor ALC1 from DNA damage sites suggesting a role for these three proteins in changes in chromatin structure after DNA photodamage.These results, taken together with the observation that PARP-1 recruitment is sub-optimal in both Cdk5KD and PARP-2KD cells, show that an intricate network of phosphorylation and poly(ADPribose) ylation occurs in response to IR that involves Cdk5 , PARP-1,PARP-2 and PARG and that is probably initiated by Cdk5’s kinase activity.

Toxoplasma gondii é um agente disseminado com um ciclo de vida complexo que envolve gatos e hospedeiros de sangue quente, incluindo o homem. Componentes vacinais são imunógenos pobres e vacinas atenuadas causam doenças crônicas. Taquizoítos irradiados à 255Gy induzem uma imunidade similar a infecção, com proteção parcial, sem estudos sobre memória. Estudamos a produção de IgG in vitro por células do baço e medula óssea de camundongos imunizados com taquizoítos irradiados e infectados. A medula óssea contém um número maior de células específicas do que o baço. As células de memória são de alta afinidade, mas IgG sérica apresentaram baixa avidez. Há também anticorpos específicos IgA nas fezes. Todas as vacinas indutoras de proteção parcial contra o desafio, que foi mais evidente em alta patogenicidade da cepa ME-49. A proteção foi proporcional tanto à quantidade de anticorpos IgG no soro ou produzidos por células da medula óssea. Nossos dados mostram claramente que os anticorpos de alta afinidade estão relacionados com a sobrevida específica de memória celular. / Toxoplasma gondii is a disseminated agent with a complex life cycle involving cats and warm blood hosts, including man. Component vaccines are poor immunogens and attenuated vaccines cause chronic disease. 255Gy irradiated tachyzoites induce the same immunity as natural infection, with partial protection, without studies on immunological memory. We studied in vitro production of specific IgG by spleen and bone marrow cells of mice immunized with irradiated tachyzoites, comparing with chronically infected animals. Bone marrow contains larger numbers of specific cells than spleen. Memory cells were of high affinity, but serum presented low avidity IgG. We also show presence of specific IgA antibodies in stools. All immunizations induce partial protection against challenge, which was more evident in highly pathogenic ME-49 strain. The protection was proportional both to the amount of IgG antibodies in serum or produced by bone marrow cells. Our data clearly shows that high affinity antibodies are related to specific memory cell survival.

Materiais poliméricos (plásticos e borrachas) abrangem uma proporção continuamente crescente de resíduos urbanos e industriais descartados em aterros, seus impactos no meio ambiente são cada vez mais preocupantes. A implementação de novas tecnologias em prol da redução dos resíduos poliméricos, aceitáveis do ponto de vista ambiental e a um custo eficaz, provou ser um grande problema, face às complexidades inerentes para a reutilização dos polímeros. A radiação ionizante tem capacidade para alterar a estrutura e propriedades dos materiais poliméricos. As borrachas butílicas e halobutílicas têm sido usadas em larga escala, numa variedade de aplicações tais como partes de pneus e artefatos diversos. O principal efeito do fóton de alta energia, como raios gama nas borrachas butílicas e butílicas halogenadas é a geração de radicais livres, acompanhada por mudanças nas propriedades mecânicas. O objetivo deste trabalho é desenvolver processos de degradação controlada (desvulcanização) de borrachas butílicas e halobutílicas (cloro e bromo), de modo a caracterizar sua disponibilidade para transformação e alteração de suas propriedades. Os resultados experimentais obtidos mostraramm que as borrachas butílica e halobutílicas irradiadas a 25 kGy e posteriormente cisalhadas podem ser usadas como ponto de partida para misturas com borracha virgem. / Polymeric materials (plastics and rubbers) attain a continuous and raising proportion of urban and industrial scraps discarded in landfills; their impact on environment are more and more concerning. The implementation of new technologies in order to reduce impacts of plastic waste on the environment, at an effective cost, proved to be a great problem, due to inherent complexity for polymers re-using. Ionizing radiation is capable to modify structure and properties of polymeric material. Butyl and halobutyl rubbers have been used within a comprehensive scale, applications such as tires spare parts and diverse artifacts. The major high energy photon effect, as gamma-rays in butyl and halo butyl rubbers consists in free-radicals generation along changes in mechanical properties.This work aims to the development of controlled degradation processes (devulcanization) of butyl and halo butyl (chlorine and bromine) rubbers, in order to characterize their availability for transformation and modification of properties. Experimental results obtained showed that butyl and halobutyl rubbers,irradiated at 25 kGy and further sheared, are able to be used as an initial point for mixtures with pristine.

No Brasil, para fins de planejamento de barreiras físicas em instalações radiográficas ou para a verificação dos níveis de restrição de dose em levantamentos radiométricos, deve ser usada a grandeza operacional equivalente de dose ambiente. Na prática, os monitores de radiação utilizados em proteção radiológica apresentam suas leituras na grandeza dosimétrica kerma no ar. Portanto, é preciso utilizar um coeficiente que converta esta grandeza dosimétrica na grandeza operacional recomendada. As normas nacionais estabelecem que o coeficiente de conversão no valor de 1,14 Sv/Gy deve ser usado para realizar esta operação, desconsiderando a diferença na distribuição espectral dos fótons dos feixes de raios X comumente encontrados em salas de radiologia convencional. O presente trabalho tem por objetivo determinar os coeficientes de conversão considerando a distribuição espectral da radiação secundária e secundária transmitida através de placas de argamassa baritada. Para atingir os objetivos propostos, foi desenvolvida uma metodologia experimental para as medições dos espectros das radiações secundárias e secundárias transmitidas usando um sistema espectroscópico com detector de CdTe e uma câmara de ionização de 1800 cm3. A região torácica de um objeto simulador antropomórfico, RANDO® Man, foi usada como região espalhadora. Foram utilizadas tensões no tubo entre 40 kV e 150 kV com intervalos na tensão de 10 kV. Os ângulos de espalhamento foram de 30°, 60°, 90° 120° e 150° em relação ao eixo do feixe primário. Como atenuador da radiação secundária foram utilizadas placas de argamassa baritada com espessuras de aproximadamente 10, 15, 20 e 25 mm. Os resultados mostram que, para a radiação secundária, os coeficientes de conversão são maiores que o valor estabelecido no Brasil. Num exemplo típico de levantamento radiométrico, a estimativa do equivalente de dose ambiente determinado usando o coeficiente de conversão calculado a partir dos espectros resultou em um valor cerca de 40 % superior ao equivalente de dose ambiente calculado a partir do coeficiente adotado pela norma nacional. / In Brazil, for planning purposes of the physical barriers in a radiographic installation and for levels verification of dose restriction in radiometric surveys, the ambient dose equivalent operational quantity should be used. In practice, radiation monitors used in radiation protection, are calibrated in dosimetry quantity air kerma. Therefore, it is important to use a conversion coefficient, which turns this dosimetric quantity into a recommended operational quantity. The rules followed in Brazil still establish that the value of the conversion coefficient, 1.14 Sv/Gy, must be used in area monitoring, disregarding differences between the beam types with different photon spectral distribution, commonly found in conventional radiology rooms. Consequently, this work aims to determine the conversion coefficients considering the spectral distribution of the secondary radiation and secondary-transmitted radiation through barium mortar plates. To achieve the proposed objectives, it has been developed an experimental method for measurement of secondary and secondary transmitted spectra using a spectroscopic system with CdTe detector and an ionization chamber 1800 cm3. The thoracic region of an anthropomorphic phantom, RANDO® Man, was used as a scatter region. The voltages used began 40 kV up to 150 kV in displacements of 10 kV, the scattering angles were 30°, 60°, 90° 120° and 150° with respect to the axis of the primary beam. As attenuator object of the secondary radiation was used barium mortar plates with thicknesses of 10, 15, 20 and 25 mm approximately. The results show that for the secondary radiation, the conversion coefficients are greater than the value set in Brazil. In a typical example of radiometric survey, the estimated ambient dose equivalent using the conversion coefficient calculated from the spectra, is a 40% higher compared to the value obtained using the coefficient recommended in Brazil.

De nos jours, les caméras sont de plus en plus utilisées lors de missions spatiales ou en centrale nucléaire pour des missions d'observations (civiles ou militaires) et de surveillance (vérification du déploiement de panneaux solaires, opérations extravéhiculaires, accident nucléaire, site de stockage). L'environnement spatial, les réacteurs civils nucléaires ou les lieux de stockage de déchets radioactifs sont des milieux radiatifs qui peuvent très fortement perturber les composants électroniques et les systèmes. Dans ces environnements, les rayonnements ionisants dégradent les paramètres électriques des composants électroniques. La dose totale ionisante conduit à l'apparition d'un nombre significatif de charges dans les oxydes des matériaux constituant les composants électroniques, modifiant leurs propriétés électriques. Il en résulte qu'une exposition à la dose totale ionisante peut entraîner une défaillance partielle ou totale d'un composant voire d'un système électronique embarqué.Dans le cadre de cette thèse, nous proposons une méthode de régénération pour guérir les paramètres électriques dégradés par la dose totale ionisante de composants électroniques soumis aux rayonnements ionisants. Cette méthode consiste à appliquer des cycles de recuit isothermes à un composant électronique. Dans un premier temps, cette méthode est appliquée sur des transistors MOS, et une étude est menée sur l'impact des différents paramètres clés du recuit (polarisation, température, durée de recuit, pas en dose entre chaque recuit). Dans un second temps, nous nous intéressons à des composants plus intégrés et plus récents tels que des capteurs d'images de type CMOS APS. Nous montrons expérimentalement l'impact d'un recuit sur ce type de composant et enfin, nous adaptons la méthode de régénération pour l'appliquer à ces capteurs APS afin d'augmenter leur durée de vie. / Nowadays, cameras are more and more used in space missions or nuclear plant for observation (civil or military) and monitoring missions (checking the deployment of solar panels, extravehicular operations, nuclear accident, and area storage). The space environment, nuclear reactors or radioactive waste storage areas are radiative environments that can greatly disturb electronic components and systems. In these environments, ionizing radiation degrades the electrical parameters of electronic components. The total ionizing dose induces significant charge build-up in oxides, degrading the electrical properties of the materials of electronic devices. That can result in the loss of functionality of the entire electronic system.In this thesis, we propose a regeneration method to recover the electrical parameters degraded by total ionizing dose of electronic components subjected to ionizing radiation. In this method isothermal annealing cycles are applied to electronic devices. In a first step, this method is applied on MOS transistors, and a study is conducted on the impact of various key parameters of annealing (bias, annealing temperature, annealing time, dose step between each annealing). In a second step, we focus on components more integrated and newer such as CMOS APS image sensors. We experiment what is the impact of annealing on this type of component and finally, the regeneration method is modified to be suitable on these APS sensors to increase their lifetime.

Neste trabalho estudamos a resistência de Deinococcus radiodurans à ação combinada de radiações convencionais, não convencionais e agentes externos. Nas irradiações com gamas, a D. radiodurans apresentou um ombro de reparo de 2 e 8kGy nas fases exponencial e estacionária, respectivamente. Nas irradiações com gamas e ajuste da suspensão celular manifestou-se radioresistência similar em ambas as fases de crescimento. Em exposições ao campo elétrico após irradiações com gamas, a D. radiodurans apresentou em ambas as fases redução do ombro de reparo. O ombro de reparo foi de 1 e 4kGy nas fases exponencial e estacionária, respectivamente. Nas exposições ao campo magnético, obtivemos um ombro de 4kGy na fase exponencial e de 6kGy na fase estacionária. Em irradiações com elétrons o ombro de reparo na fase exponencial foi completamente eliminado e na fase estacionária foi de apenas 1kGy. Este trabalho revelou novas e importantes informações referentes à radioresistência da D. radiodurans, além de fornecer subsídios para a melhoria de protocolos de radioterapia em associação com outros agentes físicos exógenos. / Several strategies have been worked out toward the enhancement of cellular radiosensibility, as the use of exogenous fields. In gamma irradiation D. radiodurans exhibited repairing shoulders of 2 and 8 kGy at the exponential and stationary phases, respectively. When gamma irradiations were combined with expositions to the electric field the repairing shoulders were reduced to 1 and 4 kGy at the exponential and stationary phases, respectively. Radioresistance was similar in both growing phases when the number of cells were approximately equalized in these two processes. On the other hand, when gamma irradiations were combined with expositions to the magnetic field the repairing shoulders were reduced to 4 and 6 kGy at the exponential and stationary phases, respectively. In irradiations with electron beams the repairing shoulder at the exponential phase was totally depleted, while at the stationary phase it was only 1 kGy. The findings of this work revealed new and important information on the radioresistance of D. radiodurans, while providing hints to the improvement of radiotherapy protocols in association with exogenous physical agents.

No processo de fabricação do gerador de 99Mo/99mTc é fundamental, não só evitar a introdução de contaminantes microbianos, como também avaliar o efeito que a atividade radioativa pode provocar em microrganismos. Os objetivos deste trabalho foram: estudar os processos de esterilização por radiação gama (60Co) dos acessórios e da coluna de alumina (Al2O3) que compõem o sistema do gerador de 99Mo/99mTc, e avaliar a eficácia da radiação gama na morte de microrganismos em geradores de 99Mo/99mTc na mínima (9,25 GBq) e na máxima (74 GBq) atividade radioativa. Acessórios do gerador foram irradiados com doses absorvidas de 15, 25 e 50 kGy e as colunas de alumina com 10, 15, 25 e 50 kGy. A alumina das colunas irradiadas foi avaliada por análise combinada de microscopia eletrônica de varredura (MEV) e análise elementar por espectroscopia de energia dispersiva (EDS), e difração de raios X. O Teflon® foi avaliado por termogravimetria (TGA) e calorimetria exploratória diferencial (DSC). Cálculos dosimétricos foram realizados para o alvo de maior dose na coluna do gerador de 9,25 GBq e 74 GBq. Suspensões quantificadas de B. subtilis e esporos de B. pumilus foram inoculadas em colunas irradiadas a 25 kGy e observou-se que a coluna de alumina representou uma barreira física para a contaminação do eluato, pois a recuperação microbiana foi reduzida. Verificou-se que o B. subtilis na forma vegetativa mostrou menor afinidade pela alumina em relação aos esporos de B. pumilus. A recuperação microbiana foi menor no gerador com atividade radioativa em relação ao gerador sem radioatividade. Foi desenvolvido um indicador biológico de esporos de B. pumilus que consistiu em uma tira de alumínio com sílica gel colocado externamente à coluna e as quantidades recuperadas tanto no gerador de 9,25 GBq quanto no de 74 GBq mostraram redução na viabilidade. O uso de filtros Sep-Pak® e 0,22 μm no sistema do gerador mostrou eficiência na retenção de 4,9 x 106 UFC de B. subtilis, garantindo a esterilidade do produto terminado. / In the manufacturing process of the 99Mo/99mTc generator it is essential not only to prevent the introduction of microbial contaminants, but also evaluate the effect of the radioactivity in microorganisms. The objectives of this work were to study the sterilization processes by gamma rays (60Co) of accessories and alumina column (Al2O3) that take part in the generator system and assess the effectiveness of gamma radiation in the death of microorganisms in 99Mo/99mTc generators of minimum (9.25 GBq) and maximum (74 GBq) radioactivities. Accessories were irradiated with 15, 25 and 50 kGy absorbed doses and alumina columns with 10, 15, 25 and 50 kGy. Alumina from irradiated columns were examined by combined analysis of scanning electron microscopy (SEM) and elemental analysis by energy dispersive spectroscopy (EDS), and X-ray diffraction. Teflon® was evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Dosimetric calculations were made for the highest dose target on 9.25 GBq and 74 GBq generator columns. Quantified suspensions of B. subtilis and B. pumilus spores were inoculated into columns irradiated at 25 kGy and it was observed that the alumina column represented a physical barrier to contamination of the eluate, as microbial recovery was reduced. It was found that B. subtilis in vegetative form showed lower affinity for alumina when compared to B. pumilus spores. Microbial recovery was lower in the generator with radioactivity than with the generator without radioactivity. A biological indicator of B. pumilus spores was developed which consisted of an aluminum strip with silica gel placed externally to the column and the microbial recovery in both 9.25 and 74 GBq generators showed reduction in viability. The use of Sep-Pak® and 0.22 μm filters in the generator system has shown efficiency in the retention of 4.9 x 106 CFU of B. subtilis, ensuring the sterility of the finished product.

Hidrogéis são membranas formadas pela reticulação de cadeias poliméricas, empregados na área farmacêutica como produtos biomédicos. Dentre os principais polímeros selecionados para a síntese de hidrogéis, destaca-se a poliacrilamida (PAAM) devido às suas propriedades como hidrofilicidade e alto grau de intumescimento. Proteínas terapêuticas e enzimas são veiculadas em hidrogéis como carreadores de fármaco ou como dispositivos para tratamento de feridas e escaras na pele. Este trabalho teve como objetivo a síntese de uma membrana à base de PAAM favorável para veiculação de proteínas. As proteínas empregadas foram papaína e albumina de soro bovino (BSA) e as etapas do processo englobaram síntese da membrana, adição das proteínas no sistema, irradiação em condições específicas e caracterização da membrana. Ao utilizar temperaturas criogênicas na síntese e na irradiação das amostras, houve predomínio de reticulação da cadeia polimérica, fato que não ocorria em temperatura ambiente. As membranas foram obtidas com incorporação dos ativos na concentração de 0,2 a 1% (p/p), obtendo-se concentração de PAAM entre 4% a 10% (p/p), as quais receberam irradiação com raios gama provenientes de uma fonte 60Co, na dose de 25 kGy. Nas condições realizadas, as membranas não apresentaram citotoxicidade nem adesão celular, o perfil de liberação das proteínas foi adequado, a papaína manteve sua bioatividade preservada apesar do decaimento biológico e, segundo estudos de carga das moléculas, a membrana possui maior afinidade com a papaína, liberando-a mais lentamente. Desta forma, o método proposto e as membranas obtidas foram apropriados para a obtenção de um biomaterial. / The use of hydrogels for biomedical purposes has been extensively investigated. Polyacrylamide (PAAM) is widely used due to properties such as hydrophilicity and swelling degree. Pharmaceutical proteins correspond to highly active substances which may be applied for distinct purposes. This work concerns the development of radio-synthesized hydrogel for protein release using papain and bovine serum albumin (BSA) as model proteins. The polymer was solubilized (1% w/v) in water and lyophilized. The proteins were incorporated into the lyophilized polymer and the hydrogels were produced by simultaneous crosslinking and sterilization using gamma radiation at 25 kGy under frozen conditions. The produced systems were characterized in terms of swelling degree, gel fraction, crosslinking density, fluid handling capacity, determination pH at point of polymer zero charge and evaluated according to protein release, bioactivity, cytotoxicity and cell adhesion. The hydrogels developed presented different properties as a function of polymer concentration and the optimized results were found for the samples containing 4-10% polyacrylamide. Protein release was controlled by the electrostatic affinity of acrylic moieties of polymer and proteins. This selection was based on the release of the proteins during the experiment period (up to 50 hours), maintenance of enzyme activity and the nanostructure developed. The system was suitable for protein loading and release and according to the cytotoxic assay and cell adhesion it was also adequate for biomedical purposes and this method was able to generate a matrix to protein release.

L'objectif de ce travail de thèse est de démontrer le potentiel des calorimètres métalliques magnétiques pour la spectrométrie bêta via une mesure du spectre du 63-Ni. Ce nucléide fait partie des émetteurs bêta pour lesquels la théorie est connue et les calculs crédibles. Nous proposons une méthode d'observation expérimentale du spectre, à basse énergie surtout, permettant de valider les calculs théoriques.Un traitement des données spécifique à l'établissement d'un spectre continu a été établi et optimisé, prenant en compte les paramètres d'une mesure cryogénique avec un calorimètre métallique magnétique et les exigences de la spectrométrie bêta.Deux types de sources ont été réalisés, un dépôt sous forme de sel de nickel à partir d'une goutte séchée de solution de NiCl2 et un dépôt métallique de nickel issu d'une électrodéposition. Les sources électrodéposées se sont révélées être le type de source adéquate pour la spectrométrie du 63-Ni.Les performances des calorimètres métalliques magnétiques, parmi lesquelles le fort rendement de détection ou le faible seuil en énergie, permettent d'obtenir des résultats suffisamment précis pour la validation expérimentale des calculs théoriques. / The aim of this thesis is to demonstrate the potential of metallic magnetic calorimeters for beta spectrometry by measuring the spectrum of 63-Ni. This nuclide is one of the beta emitters for which theory is well-known and calculation reliable. We propose a method for experimental observation, especially at low energies, which allows to validate the theoretical calculation.A dedicated data analysis has been established and optimized. It takes into account the parameters of a cryogenic measurement and also the specific requirements of beta spectrometryTwo types of sources have been realized, a deposit of nickel salt from a dried drop of a solution of NiCl2 and a metallic electroplated source of Ni. The electroplated sources turn out to be the appropriate type of source for 63-Ni spectrometry.The performances of metallic magnetic calorimeters, such as high detection efficiency and low energy threshold, lead to results precise enough to validate experimentally the theory.