ABSTRACT One of the highlighted areas in the development of new materials is the generation of micro- and nanoparticles as drug carriers which allow the progress in formulations with the ability to release active agents in a controlled way. The proanthocyanidins (PAC) extracted from the bark of the Black Wattle have stood out for their biological activities. However, most polyflavonoids have some features which limit their application in the pharmaceutical field, such as light fastness, low bioavailability of active agents, and unpleasant taste. In this context, this study aims to present the synthesis and characterization of PAC-loaded lactic-co-glycolic acid (PLGA) microparticles obtained by the multiple emulsion method. The incorporation of PAC into PLGA was successfully achieved with PAC encapsulation efficiency around 73%. Spherical microparticles were obtained with a size distribution in the range of 0.6 to 2.4 μm. The presence of PAC modified the thermal properties of the PLGA matrix. The results of in vitro assays with Vero and T24 lineage celss showed that PLGA/PAC microparticles did not promote any effect on cell proliferation by MTT assay after 24 h. The novel Acacia mearnsii proanthocyanidin-loaded PLGA microparticles have potential for application in biological systems.

Abstract: Waterborne polyurethanes (WPUs) are interesting materials for coatings when compared to solvent-based polyurethanes, once that reducing the concentration of volatile organic compounds that are harmful for human health and the environment. However, the WPU has low weathering resistance. In order to improve this behavior among others properties, inorganic fillers has been added in these systems. SiO2 particles from various sources, mainly, from agro-industrial waste, as rice husk has attracted the scientific and technological interest. In this study, the accelerated weathering essay was performed in waterborne polyurethane (WPU)/ silica (from rice husk ash) composites in order to evaluate the thermal and physical changes in these materials. These composites were prepared by two distinct methods: in situ polymerization and blending method. The highest resistance to thermal degradation and to accelerated weathering was reached with WPU/silica composites obtained by blending method due the interactions between SiO2 particles and the polymer matrices. Blending method for preparation WPU/silica composites proved to be a simpler and faster method, with no drawback for large scale application.

Menthol-loaded PLGA micro/nanospheres were synthesized using the multiple emulsion/solvent evaporation technique. Parameters such as stirring rate, external surfactant content, PLGA/menthol weight ratio, solvent evaporation and lyophilization time were evaluated as well as the degradation of micro/nanospheres in an artificial saliva medium. The menthol/PLGA micro/nanospheres thus obtained had a size distribution of between 217 nm and 13 µm and particles with spherical and dense morphology were evidenced by SEM micrographs. FTIR and TGA data showed an increase up to 60% of menthol incorporated in the micro/nanoparticles. The degradation of menthol-loaded PLGA micro/nanoparticles in artificial saliva significantly affected the particles morphology and appears to be an effective medium for releasing menthol.

Biodiesel purity expressed as fatty esters content is one of its most important quality parameters. Although several instrumental methods have been employed, gas chromatography with internal standard calibration has been the most used. Biodiesel is a very complex matrix, therefore finding a suitable internal standard (IS) is not straightforward. EN14103:2003 standard established methyl heptadecanoate (C17:0) as IS. Since this fatty ester is naturally present in some biodiesel feedstock as tallow, that standard was reviewed in 2011, and methyl nonadecanoate (C19:0) became the new IS. In turn, C19:0 produces a peak on the chromatogram that is difficult to resolve from methyl linoeate (C18:2) and metyl linolenate (C18:3) ones. In this paper, a GC-FID method for the determination of the esters content in methyl and ethyl biodiesel from canola and soy oils, using hexadecyl acetate as a new internal standard was validated. EN14103:2003 was used as reference method. Method selectivity, accuracy (t student parameter < 2.18 from both methods), repeatability (0.1 - 0.4%), intermediate precision (0.2 - 1.8%), and robustness (0.1 - 1.6%) were investigated and considered appropriate for the scope.

The final destination of PET packaging is creating economic and environmental concerns. One of the alternatives to minimize this problem would be making use of chemical recycling of this material through glycolysis with the aim to produce bis(hydroxiethyl) terephthalate, BHET monomer. This reaction is well known, but it still presents problems as BHET purity since it makes necessary the development of new catalysts highly selective. In this context, the present work studied the catalytic activity of a nanostructured material, titanate nanotubes (TNT), and compared it to a commercial catalyst (zinc acetate), which is the most used for this glycolysis reaction according to literature researches, and analyzed the influence of PET type (virgin and post-consumer) in the depolymerization for reaction times of 2, 3 and 4 hours. Using TNT as catalyst, BHET production yield and values of turnover number for the evaluated reaction times were higher than the results using Zn(OAc)2 for virgin PET, proving itself as a promising catalyst.

The development of polyester based materials with enhanced properties as well as the use of post- consumer plastics as raw material has been an increasing market demand. This work aims the synthesis and characterization of aromatic polyesters/titanium dioxide nanocomposites from PET and using TiO2 (0, 1, 3 and 5% w/w) as filler by in situ polymerization. The results obtained by DSC, XRD and FTIR analyzes evidenced an interaction between the OH groups on the TiO2 surface with the ester groups of the polymer leading to decrease of the polymer crystallinity and of hydrophilicity. By SEM images was possible to note a homogeneous distribution of the filler into polymer matrix with 1%w/w TiO2 (average particle size of 199 nm), however for larger amounts of filler (3 and 5% TiO2) revealed the aggregates formation. The results showed an improvement of thermal properties and hardness of the nanocomposites containing TiO2 nanoparticles compared to pristine polyester.

The uses of polymer blends have stimulated research to promote a better performance of existing raw materials. The implementation of blends in the production of polymeric membranes has shown great results in regenerative medicine and consequently it has improved the application of biomaterials in this area. This study aimed to evaluate the morphology and wettability of a bacterial cellulose/corn starch polymeric membrane. In relation to biomaterials, wettability is an important property to be evaluated because it is possible to observe if the degradation is accelerated even when in contact with biological fluids. The membrane was morphologically evaluated by SEM. Results showed that there was interaction between the polymers. Additionally, by the technique of contact angle it was also possible to observe the ability to absorb water, being highly satisfactory, showing a complete wetting with a contact angle of 10.7° in the initial assessment and 6.6° in the evaluation after 5 seconds.

ResumoObjetivoIncorporar o hormônio de crescimento recombinante humano em um polímero biodegradável (PLGA).Material e métodoAs matrizes foram confeccionadas através da técnica de evaporação de solventes. Foi feita uma mistura do polímero (poli ácido glicólico lático) e do hormônio do crescimento humano recombinante (Saizen® Merck Serono S.A. Aubonne, Suíça). Essa mistura foi vertida em moldes de silicone circulares de 1 cm de diâmetro e aproximadamente 2 mm de espessura, e levada para secagem em uma câmara de evaporação de solvente por 48 horas. Após esse período, as matrizes foram imersas em PBS e passaram por um banho termostatizado (ensaio de degradação hidrolítica), in vitro, à temperatura de 37°C. As amostras foram retiradas do banho no intervalo de 1, 2, 3, 4, 7, 10 e 14 dias. Foram aferidas a perda de massa, a variação do pH e a concentração do hormônio liberado em função do tempo.ResultadoA concentração do hormônio liberado em função do tempo foi aumentando até o terceiro dia. No quarto dia, houve uma queda e, no sétimo, ocorreu um aumento do hormônio liberado, estendendo-se até o décimo dia; no 14° dia, houve queda novamente. O pH teve uma queda brusca de 7,4 para 3,2 no primeiro dia, mantendo uma pequena queda até o 14° dia. A perda de massa foi gradual em relação ao tempo, como já era esperado.ConclusãoO PLGA é um bom biomaterial para confecção de matrizes com hormônio do crescimento. Revelou-se possível incorporar o rhGH nessa matriz, de modo a, então, desenvolver-se um substituto ósseo.

AbstractObjectiveIncorporate recombinant human growth hormone in a biodegradable polymer (PLGA).Material and methodThe arrays were fabricated by solvent evaporation technique. A mixture of polymer (poly lactic glycolic acid) and recombinant human growth (Saizen® Merck Serono SA Aubonne, Switzerland) was performed hormone. This mixture was poured into circular molds silicone 01cm in diameter and about 02mm thick, and carried into a drying chamber for evaporation of solvent for 48 hours. After this period, the matrices were immersed in PBS and passed through a constant temperature bath (test for hydrolytic degradation) in vitro, at a temperature of 37°C. The samples were removed from the bath in the range of 01, 02, 03, 04, 07, 10, 14 days. Mass loss, pH and concentration of hormone released as a function of time was measured.ResultThe concentration of hormone released versus time was increased until the third day. On the fourth day had a fall and on the seventh day there have been increased hormone released by the tenth day, the fourteenth day was falling again. The pH had a sharp drop from 7.4 to 3.2 on the first day and keeping a small drop until the fourteenth day. The mass loss was a gradual loss in relation to time as was to be expected.ConclusionPLGA is a good biomaterial for making breeders of growth hormone. It has proved possible to incorporate the rhGH in the array so as to then develop a bone substitute.

Embora tecnologias de captura e armazenamento de carbono (CCS) estejam recebendo grande atenção para a mitigação do efeito estufa, ainda existem muitas desvantagens, tais como o aumento dos custos e gastos de energia associados à sua implementação. No entanto, o uso de CO2 como bloco de construção C1 em síntese orgânica pode ser muito atraente para o desenho de processos ecológicos. Neste trabalho, foram estudados a sorção de CO2 e atividades catalíticas de alguns líquidos iônicos (ILs) base imidazólio para síntese de carbonato cíclico. O trabalho demonstra que a presença de um grupo nucleófilo no sistema catalítico pode melhorar seu desempenho, através da utilização de um IL com ânion halogenado ou por mistura de co-catalisador halogenado com ILs. A última abordagem permitiu a obtenção de um sistema de captura de CO2 eficaz, constituída por IL fluorado mais ZnBr2 que realiza a síntese de carbonato cíclico com 90% de rendimento e 82% de seletividade.

Although the carbon capture and storage (CCS) technologies are receiving great attention for mitigation of greenhouse gas effect, the increasing costs and energy penalties associated to its implementation are still major drawbacks. However, the use of CO2 as a C1 building block in organic synthesis can be very attractive for the design of environmentally friendly processes. In this work, we have studied both the CO2 sorption and catalytic activities of some imidazolium based ionic liquids (ILs) for cyclic carbonate synthesis. The work demonstrates that the presence of a nucleophilic group in the catalytic system can enhance its performance by the use of an IL with a halide anion or by mixing a halide co-catalyst with ILs. The latter approach allowed to obtain an effective system for CO2 capture constituted by a fluorinated IL plus ZnBr2 that performs cyclic carbonate synthesis with 90% yield and 82% of selectivity.

Rising anthropogenic CO2 emissions are considered a major contributor to the greenhouse effect. There are several options for reducing atmospheric CO2 levels, and among these alternatives, Carbon Capture and Storage (CCS) has been identified as an effective and promising approach. This work investigated the feasibility of using serpentinite as a vehicle for carbon storage presenting a source-sink match. The main results of the work confirmed that serpentinite is appropriate for the carbonation process due to the high concentration of Mg in its composition.

Nas últimas décadas têm sido desenvolvidos novos materiais sintéticos que possuam biofuncionalidade e biocompatibilidade para que se tornem um biomaterial. Polímeros bioestáveis têm uso generalizado no campo biomédico, sendo que muitos avanços em biomateriais poliméricos têm ocorrido na busca de melhorias aos implantes cardiovasculares. Atualmente, os materiais sintéticos mais utilizados para a fabricação de próteses vasculares são o PET e o PTFE devido a sua estabilidade química após o implante. Neste trabalho é apresentado um estudo das propriedades térmicas e mecânicas de dispositivos comerciais à base de PET e PTFE, bem como sua citotoxicidade em células de fibroblastos de camundongos, 3T3-NIH, através de testes para a avaliação da viabilidade celular (teste VN e MTT). Estes materiais apresentaram grande estabilidade térmica (acima de 300 ºC), mesmo após 270 dias de degradação in vitro e um comportamento elástico (deformação máxima de 186±22% para o PET e de 65±19% para o PTFE). A viabilidade celular por VN e MTT do dispositivo de PTFE foi superior a 80%, permitindo classificar o mesmo como não citotóxico. No teste de VN, o dispositivo de PET não apresentou efeito citotóxico, contudo os resultados por MTT indicaram que o mesmo causa alteração da funcionalidade mitocondrial, independente da dose e tempo avaliados.

In recent decades new synthetic materials have been developed with adequate biofunctionality and biocompatibility to become a biomaterial. Biostable polymers have widespread use in the biomedical field, and many advances in polymeric biomaterials have been made in the search for improvements to cardiovascular implants. Currently, the most commonly used synthetic materials for the production of vascular grafts are PTFE and PET, due to their chemical stability after implant. In this work, a study of the thermal and mechanical properties of the commercial devices based on PET and PTFE is reported, as well as their cytotoxicity in mouse fibroblast cells, 3T3- NIH, through tests for the evaluation of cell viability (MTT test and VN). These materials showed high thermal stability (over 300 ° C), even after 270 days in vitro degradation and elastic behavior (maximal strain value of 186±22% by PET and 65±19% by PTFE). Cell viability by VN and MTT of PTFE device was more than 80%, thus, classified as non-cytotoxic. For PET device, VN test showed no cytotoxic effect, however the results obtained by MTT indicated that it causes alteration of mitochondrial function, independent of dose and time measured.

Due to their versatility, polyurethane (PU) foams have many different applications, such as sponges, filling materials in furniture, automotive seats and clothes, among others. It is also one of the main refrigerator components serving as a heat insulating material. As PUs find different application niches, they must be largely produced and, consequently, lots of waste are generated. In this work we intend to contribute to the recycle of this waste. The recovery of polyol from flexible polyurethane foams was carried out using the glycolysis process and testing different catalysts. Grounded polyurethane and a solvent, diethyleneglycol (DEG), were kept at 200 ºC and under nitrogen atmosphere during three hours in the presence of a catalyst. All catalysts tested promoted the polyol mixture formation, with Zinc acetate producing the best depolymerization rate. The catalysts efficiency for the depolymerization reaction follows the order: DBTDL< BTO< HBTO< DEA ≈ Ba(Ac)2< MEA ≈ KAc< Zn(Ac)2.

OBJETIVO: Este estudo, in vitro, avaliou a quantidade de extrusão apical de "debris", após o preparo químico-mecânico do canal radicular, utilizando diferentes técnicas. METODOLOGIA: Sessenta incisivos inferiores humanos hígidos foram aleatoriamente divididos em três grupos: Grupo A: técnica coroa-ápice manual; Grupo B: técnica coroa-ápice mecanizada com sistema de rotação oscilatória; Grupo C: Protaper, técnica mecanizada com sistema de rotação contínua. As raízes foram imersas em 2,3 mL de água destilada. Após os preparos, a água destilada de cada amostra foi filtrada, e o filtro de papel, contendo o material sólido extruído, foi pesado em uma balança analítica de precisão. Os dados foram analisados estatisticamente pelos testes Kolmogorov-Smirnov e Kruskal-Wallis ao nível de significância de 0,05. RESULTADOS: A análise estatística demonstrou que o grupo C apresentou valores superiores de "debris" do que os grupos A e B. CONCLUSÃO: A técnica rotatória contínua com Pro-taper produziu maior quantidade de extrusão apical do que as técnicas coroa-ápice manual e mecanizada com sistema de rotação oscilatória. A direção da instrumentação, se cérvico-apical ou ápico-cervical, parece ser o fator mais determinante na extrusão de "debris" independente desta ser realizada manual ou mecanizada.

PURPOSE: This in vitro study assessed the amount of debris extruded apically after preparation with different techniques. METHODS: Sixty healthy, extracted, human mandibular incisors were randomly divided into 3 groups: Group A - hand crown-down technique; Group B - crown-down technique with enginedriven rotary reciprocating instruments; Group C - Protaper: engine-driven continuous rotary instrumentation. The roots were immersed in 2.3 mL of distilled water. After preparation, the water in each tube was filtered to collect solid material extruded, and the filters were weighed using a precision scale. Data were analyzed by Kolmogorov-Smirnov and Kruskal-Wallis tests at the 0.05 level of significance. RESULTS: The statistical analysis showed that group C had significantly higher values of debris than groups A and B. CONCLUSION: The instrumentation using a continuous rotary technique, Protaper, produced greater apical extrusion than the hand and engine-driven crown-down techniques. The direction of instrumentation, whether cervical-apical or apical-cervical, seems to be a more important factor influencing apical extrusion than whether the instrumentation was performed by hand or was engine-driven.