Orientadores: Cecília Amélia de Carvalho Zavaglia, Sidney Nicodemos da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-20T18:41:35Z (GMT). No. of bitstreams: 1 Osthues_RachelMary_D.pdf: 11656102 bytes, checksum: c5134deb1de01700c21abffc9c8c165d (MD5) Previous issue date: 2012 / Resumo: A utilização de biocerâmicas a base de fosfato de cálcio encontra grande aceitação clínica na substituição de tecidos ósseos, e mesmo no preenchimento dérmico, devido à sua similaridade química com parte mineral de ossos e dentes. Em função desta similaridade, os fosfatos de cálcio apresentam, dentre outras propriedades importantes, elevada biocompatibilidade, e na maioria das vezes exibem bioatividade e/ou osteocondução. Estes materiais não induzem reações inflamatórias ou imunológicas, agudas ou crônicas, ou seja, causam mínima irritação, limitada ao local de contato, e mínimas reações alérgicas. Dentre os fosfatos de cálcio, as apatitas formam a maior parte das cerâmicas de interesse biológico e podem ser constituídas de hidroxiapatita e beta-fosfato tricálcico, mistura chamada de fosfato de cálcio bifásico. Classicamente, este material se encontra disponível em blocos cerâmicos, densos ou porosos, ou na forma de materiais particulados (grânulos, pós e colóides). Na forma de grânulos ou pós, o formato esférico é preferido por se conformar melhor em locais de implantação irregulares, além de apresentarem propriedades reológicas mais satisfatórias em produtos injetáveis. Vários métodos de produção de micropartículas têm sido relatados, alguns empregando equipamentos e matériasprimas de custos elevados, e outros apresentando o inconveniente de utilizar solventes orgânicos altamente tóxicos, em pelo menos uma etapa do processamento, que devem ser removidos. Neste estudo, foi desenvolvida uma rota de produção de biocerâmicas particuladas de fosfato de cálcio bifásico, com forma esférica, eliminando a utilização de equipamentos e matérias-primas de custos elevados, e de substâncias tóxicas, reduzindo, assim, o número de etapas e o custo do processo. O processamento foi baseado na imiscibilidade de líquidos, com formação de uma emulsão água/óleo, utilizando uma mistura de solução de gelatina e fosfato de cálcio bifásico (fase dispersa) e óleo de canola alimentício (fase contínua). As micropartículas obtidas foram caracterizadas física, química e biologicamente, e foram avaliadas quanto ao potencial de incorporação e de liberação de medicamentos. Os resultados mostraram que o método aprimorado produziu micropartículas polidispersas, sem resíduos das substâncias químicas utilizadas no processamento, com morfologia esférica e estrutura porosa. As microesferas produzidas não apresentaram efeitos citotóxicos para a linhagem celular estudada e apresentaram potencial para incorporação e liberação do antibiótico gentamicina / Abstract: The biphasic calcium phosphate is greatly applied in the replacement of osseous tissues and as dermal fillers due to its chemical similarity with the mineral part of bone and teeth. Due to this similarity, the calcium phosphates present, among other important properties, high biocompatibility, bioactivity and/or osteoconduction. They do not induce inflammatory or immune reaction, acute or chronic, causing minimal irritation that is limited to the local contact, and cause minimal allergies. Among the calcium phosphates, the apatites form the major part of the ceramics of biological interest, and can be composed of hydroxyapatite and beta-tricalcium phosphate, namely biphasic calcium phosphate. This material is classically available in ceramic blocks, dense or porous, or in particulate form (granules, powders and colloids). Granules and powders with spherical shape are preferred because they conform better in irregular implantation sites, and offer more satisfactory rheological properties when used in injectable products. Several methods for microparticles production have been reported, some employing expensive equipments and raw materials, and other presents the disadvantage of using highly toxic organic solvents, in at least one processing step, which need to be removed. In this study a production route of particulate biphasic calcium phosphate bioceramics with spherical shape was developed, eliminating the use of equipment and raw materials of high cost and toxic substances, thereby reducing the number of process steps and cost. The process was based on liquid immiscibility, generating a water/oil emulsion, using a mixture of gelatin solution and biphasic calcium phosphate (dispersed phase) and food grade canola oil (continuous phase). The microparticles obtained were physically, chemically and biologically characterized, and their incorporation and drugs release potential was also evaluated. The results showed that the improved method produced polydisperse microparticles without residues of chemicals used in processing, spherical shape and porous structure. The microspheres produced showed no cytotoxic effects for the cell line studied and showed potential for drugs incorporation and release of the antibiotic gentamicin / Doutorado / Materiais e Processos de Fabricação / Doutora em Engenharia Mecânica

Les infections nosocomiales post-opératoires en sites osseux posent un problème majeur de santé publique. L'utilisation de biocéramiques bioactives et résorbables qui présenteraient des propriétés antibactériennes apparaît comme une des solutions les plus prometteuses pour lutter contre l'invasion de micro-organismes au niveau du site opératoire. Les apatites nanocristallines biomimétiques se révèlent être des candidats de choix pour ces applications en raison de leur similitude avec le minéral osseux et de leur forte réactivité de surface. Cependant, elles ne possèdent pas de propriétés antibactériennes intrinsèques, ce qui peut potentiellement être amené par un dopage ionique approprié. Dans ce contexte, ce travail traite de la synthèse et de la caractérisation physico-chimique d'apatites biomimétiques enrichies avec des cations zinc (Zn2+), cuivre (Cu2+) ou argent (Ag+) ou avec des anions oxygénés de type peroxydes qui présenteraient ces facultés antimicrobiennes ; puis sur l'évaluation préliminaire de leurs propriétés (micro)biologiques. Dans un premier temps, l'étude de systèmes apatitiques non dopés a indiqué qu'à l'instar du minéral osseux les apatites nanocristallines présentaient des cristaux de dimensions nanométriques dont la composition chimique s'éloignait de la stoechiométrie et exposant des environnements ioniques non-apatitiques hydratés en surface des nanocristaux. L'influence des paramètres de synthèse a été évaluée et révèle que le temps de maturation, la température, le pH et la nature des sels de phosphate impactent significativement les caractéristiques physico-chimiques de ces composés. Nous montrons également que les conditions de post-traitement (ré-immersion, traitement thermique, mise en forme) peuvent aussi modifier significativement les caractéristiques finales des biocéramiques. Dans un second temps, ce travail a révélé que l'enrichissement d'apatites nanocristallines avec des ions Zn2+, Cu2+, Ag+ ou des espèces oxygénées était possible – avec des taux de dopage limites qui ont été évalués – mais générait des modifications physico-chimiques notables en particulier en termes d'état de cristallinité et de teneur en environnements chimiques non-apatitiques. Le zinc et le cuivre engendrent des effets similaires et semblent agir en tant qu'inhibiteur de croissance cristalline. L'argent, bien que monovalent, ne modifie pas significativement les processus de formation et de croissance des nanocristaux d'apatites. En revanche, la présence de peroxyde d'hydrogène dans le milieu réactionnel conduit à la formation d'apatite dont l'état de cristallinité est augmenté. Le choix de paramètres de synthèse adéquats, influençant notablement les mécanismes d'incorporation des ions, s'est avéré déterminant pour l'obtention d'apatites nanocristallines monophasées et dopées. Des tests biologiques préliminaires ont été réalisés pour évaluer la cytotoxicité de ces composés et le comportement de cellules ostéogéniques (de types ostéoblastes et ostéoclastes). L'évaluation d'éventuelles propriétés antibactériennes a également fait l'objet de ce travail, dans le cadre d'une collaboration internationale. Parmi les formulations présentant des propriétés antibactériennes mesurées, les apatites biomimétiques enrichies en argent apparaissent au vu de ce travail comme les candidats les plus prometteurs pour conférer l'effet antibactérien nécessaire aux applications visées. / Hospital acquired infections in osseous sites are a major issue of public health. The use of bioactive and resorbable bioceramics that present antibacterial properties appears as one of the most promising solution against microorganisms invasion of the surgical site. Biomimetic nanocrystalline apatites belong to the choice candidates for those applications thanks to their similarities with the bone mineral and their high surface reactivity. Nevertheless, they don't possess intrinsic antibacterial capacity, property that can be reached by a suitable ionic enrichment. In this context, this work deals with the synthesis and the physico-chemical characterization of such biomimetic nanocrystalline apatites doped with zinc (Zn2+), copper (Cu2+) or silver (Ag+) cations or with oxygenated anions like peroxides that would present antibacterial activity; then their (micro-)biological properties have also been studied. As a first part, study of apatitic non-doped systems shows that, as well as bone mineral, nanocrystalline apatites exhibit nano-sized crystals which chemical composition depart from stoichiometry and possess hydrated non-apatitic environments on their surface. The influence of synthesis parameters has been studied and reveals that maturation time in solution, temperature, pH or the nature of starting phosphate salts impact significantly the physico-chemical characteristics of those compounds. We also point out that post-treatment conditions (re-immersion, thermal treatment, forming) can significantly modify final characteristics of those bioceramics. As a second part, this work reveals that nanocrystalline apatites enrichment with Zn2+, Cu2+, Ag+ or oxygenated species seem to be possible – with maximal doping rates that were evaluated – but generate significant physico-chemical modifications, especially in terms of crystallinity state or non-apatitic chemical environments content. Zinc and copper act on a similar way on apatite compound and exhibit a crystal growth inhibitory role. Silver, even with a single positive charge, don't modify significantly the formation and the growth mechanisms of apatites nanocrystals. On the opposite, hydrogen peroxide presence in the synthesis media generates the formation of apatites which crystallinity state is improved. All of those results suggest that synthesis parameters are determining to obtain doped nanocrystalline apatites and that they influence notably the incorporation mechanisms of ions. Finally, preliminary biological tests have been realized in order to evaluate the cytotoxicity and the behavior of osteogenic cells (osteoblast and osteoclast type) in contact with those compounds. The evaluation of potential antibacterial properties is also discussed in this work as part of an international collaboration. Among formulations that exhibit measured antibacterial activity, silver doped biomimetic apatites appear as the most promising candidates to confer antibacterialness necessary for the envisaged applications.

Argon oxygen decarburization slag (AOD) was tested in batch and column experiments to investigate its phosphorus (P) removal performance. The effects of factors such as AOD dose, initial P concentration of the feeding solution, and aging on the P removal ability of the slags were analyzed. In a column experiment, electric arc furnace slag (EAF), blast furnace slag (BFS) and AOD were combined in five different ways to determine optimal conditions for P removal. In another column experiment, the three types of slag were modified with polyethylene glycol (PEG) and NaOH to adjust their dissolution properties and the effect on P removal performance was examined. In the batch experiments, AOD exhibited very promising P removal ability. It removed 94.8% of P from 6.5 mg P L-1 synthetic solution in 4 hours with a dose of 5 g L-1. Maximum P removal capacity of 27.5 mg P g-1 was achieved. In the dual-filter column experiment, the column packed with only EAF had the best P removal performance (consistently above 93%). Amorphous calcium phosphate (ACP) was identified as the main P species in the five slag samples collected from the outlet chambers. The contributions from crystalline calcium phosphate (Ca-P) and P adsorbed on iron/aluminum (hydr)oxides were greater in samples from the inlet chambers. The P speciation results revealed that P was predominantly removed by the slags through formation of ACP. The second column experiment showed that modification with PEG and NaOH solution only enhanced short-term P removal by the slags. However, exhaustion of the modified slags occurred much earlier, indicating that the modification process had shortened the lifespan of the slags. Untreated AOD showed better P removal than untreated EAF until pore volume 244, probably due to faster dissolution rate of gamma dicalcium silicate (dominating in AOD according to the XRD results) than of beta dicalcium silicate (dominating in EAF). / <p>QC 20170830</p>

Orientador: Cecilia Amelia de Carvalho Zavaglia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-07T21:15:57Z (GMT). No. of bitstreams: 1 Leal_ClaudeneteVieira_M.pdf: 5685507 bytes, checksum: 57585e6d19469dc1898123b62c967679 (MD5) Previous issue date: 2006 / Resumo: Os cimentos ósseos a base de fosfato de cálcio são materiais cerâmicos que apresentam biocompatibilidade devido a sua composição química semelhante à dos ossos, e bioatividade, promovendo a osteocondução. Com essas características, é possível a utilização desses materiais como implantes ósseos ou como preenchimento. Os cimentos de fosfato de cálcio são materiais constituídos por um pó e um líquido, que, ao serem misturados formam uma pasta que endurece espontaneamente à temperatura ambiente ou corpórea como resultado da precipitação de um ou vários fosfatos de cálcio. O pó pode ser composto por um ou vários fosfatos de cálcio, outros sais de cálcio e aditivos orgânicos. O líquido pode ser água ou soluções aquosas de compostos de cálcio ou fosfato. A proposta desse trabalho foi estudar a síntese de monólitos de fosfatos de cálcio baseado no sistema ß-Fosfato Tricálcio/Ácido Fosfórico (ß-TCP/H3PO4), que produz hidrogeno fosfato de cálcio dihidratado (DCPD), um cimento de fosfato de cálcio que possui como principal vantagem baixo custo e a desvantagem de possuir pH ácido, podendo causar necrose em tecidos. Para contornar esse problema, o DCPD foi convertido em apatita pela hidrólise em solução alcalina. O estudo envolveu a síntese do ß-TCP, a preparação do cimento, caracterizações físicas e químicas e o estudo do cimento em Fluido Corpóreo Simulado (FCS), solução que simula o plasma sanguíneo humano, para avaliar seu comportamento in vitro / Abstract: Calcium phosphate bone cements are ceramics materials that present biocompatibility because of their chemical composition similar to the human bone, and bioactivity, promoting osteocunduction. Due to these characteristics, it is possible the use of these materials as bone implants. Calcium phosphate cements are composed of a powder and liquid phases, which, when mixed form a paste that hardens spontaneously as result of the precipitation of one or more calcium phosphates. The powder may be composed of one or some calcium phosphates, others salts and organics additives. The liquid may be water or calcium phosphates aqueous solutions. The purpose of this work is the synthesis of calcium phosphate monoliths based on ß-tricalcium phosphate/ortho-phosphoric acid (ß-TCP, Ca3(PO4)2/H3PO4), that produce dicalcium phosphate dehydrate (DCPD, CaHPO4.2H2O) as phase precipitated as a result of the setting reaction. DCPD is inexpensive, but is quite soluble and has an acidic hydrolysis, which may cause necrosis in vivo. To resolve this problem, DCPD was converted in apatite phase by hydrolysis in NaOH aqueous solution. This study included ß-TCP synthesis, cement preparation, chemical and physical characterizations and the study of the cement in Simulated Body Fluid (SBF), with ion concentrations nearly equal to those of human blood plasma, to evaluate the in vitro behavior / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Orientadores: Mario Alexandre Coelho Sinhoreti, Americo Bortolazzo Corrrer / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-26T12:38:53Z (GMT). No. of bitstreams: 1 Felizardo_KlissiaRomero_D.pdf: 5538718 bytes, checksum: 380cb510516fc2b1b84875f344139970 (MD5) Previous issue date: 2015 / Resumo: O objetivo do estudo foi gerar uma nova metodologia restauradora, através de um compósito fluído fotopolimerizável com fosfatos de cálcio e incorporação de tri-metafosfato de sódio em primer autocondicionante para auto-produção de fosfoproteína biomineralizadora da matriz de colágeno na interface de união. A hipótese desse trabalho foi de que a inovadora metodologia irá recuperar as propriedades mecânicas, remineralizará e aumentará a longevidade da interface de união. No Capítulo 1 foi realizado análise qualitativa em relação à presença de fosfato e apatita carbonata nas amostras de dentina desmineralizada e após contato com os compósitos experimentais (VSG1- 0% fosfato, VSG2- 10% fosfato, VSG3- 20% fosfato e VSG4- 30% fosfato) armazenados em água destilada e solução de PBS no período de 24h, 7 dias, 1 e 3 meses. As amostras foram analisadas por espectroscopia (ATR / FTIR) e análise microscópica (ESEM / EDX). Os dados foram submetidos à análise de variância de três fatores e teste de Tukey ('alfa'=0.05). Em 24h os maiores picos referentes às bandas de apatita carbonatada (CO32- - v2) fosfato (PO43- - v1,v3) e bruxita (DCPD- vO-H) foram para os grupos VSG2 (água destilada) e VSG3 (PBS). Em 7 dias esses picos diminuiram e ocorreu aumento dos picos para os grupos VSG1 (água destilada), VSG2 (PBS) e VSG4 (PBS). Após 1 mês, o material VSG2 (PBS) apresentou aumento do pico, por outro lado o grupo VSG4 (PBS) manteve-se similar ao do período de 7 dias. Aos 3 meses, nota-se aumento para o material VSG3 (água destilada) e grupo controle (VSG1) em PBS. A análise em EDX não mostrou diferença estatística entre os grupos no decorrer do tempo. No Capítulo 2, o objetivo foi avaliar a influência de fosfato de cálcio como partículas de carga em relação ao grau de conversão, dureza, resistência flexural e módulo elástico. O material experimental VSG4 mostrou maiores valores de dureza após 6 meses e maior grau de conversão nos períodos de 3 meses e 6 meses. Maiores valores de resistência à flexão foram encontrados para o material experimental VSG2 bem como para o material comercial Wave HV (SDI). Maior módulo de elasticidade foi obtido para o material VSG4, valores estes similares aos obtidos para o material comercial Filtek Z350XT (3M/ESPE). Assim, pode-se concluir que a utilização de fosfatos de cálcio não afetou as propriedades mecânicas após envelhecimento em solução de PBS. No Capítulo 3, o objetivo foi avaliar por microscopia de confocal e microscopia óptica a micropermeabilidade por penetração de corante fluoresceína e nanoinfiltração por nitrato de prata amoniacal na camada híbrida assim como a resistência adesiva nos períodos de 24 h e 6 meses em solução de PBS. Os dados referentes ao teste de união foram submetidos à análise de variância de dois fatores e teste de Tukey ('alfa'=0.05). Os resultados mostraram que em relação à resistência adesiva não houve diferença estatística entre os grupos e período de armazenamento. A inclusão de fosfato de cálcio e o uso de tri-metafosfato de sódio auxiliaram no processo de remineralização para o material experimental VSG3 e VSG4 os quais mostraram melhores resultados, reduzindo a permeabilidade dentinária após 6 meses / Abstract: The aim of this study was to generate a new therapeutic restorative methodology through a flowable composite with bioactive calcium phosphates and incorporation of sodium tri-metaphosphate in self-etching primer will serve as a biomimetic analogs to self-phosphoprotein biomineralization production of collagen within the matrix the bonded interface. The hypothesis is that the revolutionary biomineralisation will recover the biomechanical properties, remineralise and increase the longevity of the bonded interfaces. In the chapter 1 was designed to qualitatively compare the presence of phosphate and carbonated apatite between demineralized dentin samples and experimental composite (VSG1- 0% phosphate, VSG2- 10% phosphate, VSG3- 20% phosphate e VSG4- 30% phosphate) storage in distilled water and PBS solution in 24h, 7 days, 1 e 3 months. The samples were analyzed by (ATR/FTIR) and (ESEM/EDX). Data were subjected to variance analysis with three factors and Tukey ('alfa' = 0.05). The results showed that in 24 hours the higher peak related the bands of carbonated apatite (CO32- - v2), phosphate (PO43- - v1,v3) and brushite (DCPD- vO-H) was found to the experimental material VSG2 (distilled water) and VSG3 (PBS). After 7 days, these same peaks suffered a drop therefore having an increased peak to control group VSG1 (distilled water), VSG2 (PBS) and VSG4 (PBS) groups. At 1 month , the material VSG2 (PBS) showed an increase in their peak, on the other hand VSG4 group (PBS solution) was maintained as compared to results 7 days and after 3 months, was an increase in the peaks to VSG3 materials (distilled water) and control group (VSG1) in PBS solution. The EDX analysis showed no statistical difference between the groups over time. In the chapter 2, the objective was to evaluate the in?uence of calcium phosphate as a filler in experimental composite and their correlation with the degree of conversion, microhardness, flexural resistance and elastic modulus. The experimental material VSG4 showed higher hardness values after 6 months and higher degree of conversion at 3 months and 6 months. Further flexural strength values were found for the experimental material VSG2 well as the commercial material Wave HV (SDI). Higher elasticity modulus was obtained for the experimental material VSG4, similar values to the commercial Filtek Supreme (Z350XT- 3M/ESPE). Thus, it can be concluded that the use of calcium phosphate did not affect the mechanical properties after storage in PBS solution. In the chapter 3, the aim was evaluated by confocal microscopy and optcial microscopy the micropermeability by fluorescein dye penetration and the nanoleakage by ammoniacal silver nitrate as well as the adhesive strength over 24h and 6 months in buffer solution (PBS) by microtensile test. Data on microtensile test were subjected to variance analysis with two factors and Tukey ('alfa'= 0.05). The results showed that the bond strength was not statistically different between the experimental groups. The calcium phosphate inclusion as filler particles and the use of tri-sodium metaphosphate aided in the remineralization process mainly to the experimental material VSG3 and VSG4 which showed better micropermeability and nanoleakage reducing dentin permeability after 6 months. / Doutorado / Materiais Dentarios / Doutora em Materiais Dentários

Tooth enamel is the hardest and most resistant highly mineralized inorganic component in mammalian bodies that significantly affects both the life quality and expectancy of an indi- vidual. Its specific qualitative properties are given by the biomineralization process responsible for its formation. In this process the mineralization of hydroxyapatite (HAp), the only inor- ganic phase composing the mammalian hard tissues, is controlled by activity of enamel-forming cells ameloblasts and their products. Over the past years, the studies of enamel matrix pro- teins, their structure, composition and function has become the prevalent field of experimental investigation. However, unique enamel qualities, which enable the teeth to withstand high pressure and stress demands, cannot be accurately assessed without the thorough systematical study of its mineral compound. In this thesis, I focus on the crystallographic and compositional characteristics of enamel hydroxyapatite and their influence on the mechanical properties of teeth. Obtained results are discussed in context of developmental and adaptation dynamics of mammalian species. The main aspect of the work is to extend our knowledge about the protein-mediated mineraliza- tion process from the perspective of inorganic compound and its contribution to the...

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This thesis focuse on bariatric-metabolic surgery and its impact on serum concentrations of various metabolic parameters. The thesis is divided into two parts - theoretical and practical. Basic facts about bariatric-metabolic surgery such as its history, indications, contraindications, surgical methods and their results, nutrition after surgery and the frequency of micronutrient's deficits are described in the theoretical part. Furthermore, information about calcium-phosphate metabolism and metabolites such as calcium, phosphorus, magnesium, vitamin D, vitamin K, parathyroid hormone and osteomarkers is also included. The influence of nutrition and nutritional status on the quality of bone tissue is also mentioned. Last section of the theoretical part is focused on the important vitamins and minerals. The practical part discusses measurements of selected metabolites in serum before and half a year after the surgery. Results of questionnaires which were given to respondents are also included. Questionnaires were focused on lifestyle, nutrition, physical activities and whether the patients take some supplements of micronutrients and protein concentrates. The goal of this work is to evaluate the effect of the surgery on serum concentrations of metabolic parameters and their effect on the health and...

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The report formulates the experiments conducted to remove phosphorus from the return sludge wastewater subjected to side-stream hydrolysis. The experiments are conducted using the wastewater from the outlet of side-stream hydrolysis and is tested in a laboratory at the Duvbackens wastewater treatment plant in Gävle. Chemical precipitation is used in the experiments and displays remarkable results using magnesium chloride and calcium chloride as the precipitants. A successful removal rate of 79-99% is achieved through this method. The phosphate phosphorus content is chosen to be the criterion for estimating the phosphorus removal rate. Possible parametric variations are also reviewed in the report. The decline in ammonium nitrogen is also studied alongside. Struvite and calcium phosphate are the possible precipitates and are recovered with the prospect of recycling. Both the precipitates are known as slow fertilizers and are used in the agricultural industry. If recovered by proper means, these precipitates can reduce the pressure on phosphate industry and on naturally occurring phosphate rocks. Calcium phosphate is selected among the precipitation methods for its rapid reaction and its minimum response to parametric variations. It also expresses a faster settling property with a clear solution after precipitation. The removal and recovery of phosphorus from the side-stream hydrolysis is evaluated with a notion to operate in a pilot scale.