Abstract Evaluate of cashew nut shell liquid (alginate-CNSL) on TBARS, physicochemical attributes and microbial growing of beef steak was investigated. Three edible coating treatments were prepared: (1) control (uncoating); (2) sodium alginate coating (no additive); and (3) active coatings of sodium alginate added cashew nut shell liquid (alginate-CNSL) at 1% into. Color indexes and water holding capacity were not affected by coating treatments. The pH of the beef samples from the control treatment increased at storage time, and the beef involved with alginate-CNSL coating maintained a pH stable. Alginate-CNSL coating promoted cooking loss lower after 3rd day of storage. Alginate-CNSL coating promoted a lower shear force decrease compared at control and sodium alginate coating. Alginate-CNSL coating reduced lipid oxidation (TBARS) and microbial growing (mesophiles and psychrophiles counts) in beef compared others treatments. Active coating from CNSL (1%) improved the beef preservation, reducing lipid oxidation and microbial growing, until the 6th day of storage stability.

ABSTRACT Miniaturization has been a trend in the instrumentation of chemical analyzes. The interest in miniaturization stems from the perceived benefits of faster, easier, less expensive and less wasteful analyzes than the tradition analyses. Thus, this work proposes a miniaturization of photocatalytic tests using a microplate reader for the analysis of several results, using only microliters of solution. The present work investigates the heterogeneous photocatalysis of the eosin yellow, acid yellow 73 and basic yellow 2 dyes, in the presence of zinc oxide (ZnO) and titanium dioxide (TiO2) catalysts, under irradiation in the visible light and ultraviolet light. Dye degradation was evaluated using a microplate reader (Elisa Polaris®), a photometric device that performs colorimetric readings in the 0-3 absorbance (ABS) range at wavelengths of 405, 450, 492 and 630 nm. The kinetic study was performed using the Langmuir-Hinshelwood law. It was verified that the degradation rates were higher than 90% over a period of 120 minutes for all the studied systems, especially the system composed of acid yellow dye 73 and the ZnO catalyst, which reached a degradation of 96.23% in 120 minutes.

The present study aimed to investigate the degradation of poly(ethylene oxide) (PEO) in the presence of cationic dye crystal violet irradiated under visible light. The preparation of the samples was done in the form of films obtained by casting. Degradation tests were carried out by 120 hours at room temperature. The degradation kinetics of the dye and polymer were accompanied by UV-Vis spectrophotometry and viscosimetry technique. The UV-Vis Spectra showed 81.2% degradation of the dye. In addition, it was observed a broadening of the absorption band of the polymer and the reduction of its viscosity, which features degradation. In this way, it is possible to affirm that the crystal violet dye, at the studied concentration, contributed to the degradation process of PEO.

Layered or fibrous clay minerals are used as adsorbents because they have good performance to remove inorganic and organic species. In this work, a Brazilian fibrous clay mineral was applied to remove Remazol Yellow GR industrial dye from simple and binary systems; this was performed in the presence of lead in the latter case. The adsorption efficiency was investigated under various conditions of pH, time, temperature and dye concentration. The experimental data were fitted to the kinetic pseudo-first- and pseudo-second-order models, and the isotherms were fitted to the Langmuir and Freundlich models. The maximum adsorption capacity was 20.08 mg g-1 at pH 2, 240 minutes and 298 K, and these data were better fit by the kinetic pseudo-second-order model. The equilibrium study was fitted to the Langmuir model at 298 K and Freundlich for other temperatures and binary systems. The dye sorption in the presence of lead was decreased to 15 mg g-1. Therefore, palygorskite behaved as a promising solid for treating effluents.

Nas últimas décadas o uso de argilominerais nas áreas de Ciência e Engenharia de Materiais tem recebido notória atenção para a sua utilização no carreamento de fármacos. Dentre os diversos tipos de argilas, as fibrosas e as tubulares tem sido utilizadas na preparação de bionanocompósitos, devido as suas propriedades inerentes, como exemplo a elevada área superficial. Esta pesquisa visou o levantamento bibliográfico da utilização das argilas tubulares e fibrosas para o carreamento de fármacos. A busca por artigos foi realizado no banco de dados Web of Science, utilizando combinação dos termos: Fibrous Clay and drug delivery, Tubular Clay and drug delivery, Halloysite and drug delivery, Imogolite and drug delivery, Palygoskite and drug delivery e Sepiolite and drug delivery. Foram encontrados o total de 36 artigos durante a pesquisa. Observou-se que a maioria dos artigos utilizam as argilas em combinação com outros materiais (com formação de compósitos e blendas), principalmente polímeros, a fim de expandir as propriedades que melhoram a vetorização de insumos farmacêuticos ativos (IFAs), tais como a modificação do tamanho dos poros, do pH, da energia de ligação entre as moléculas, entre outros. Assim, evidencia-se que o interesse pela utilização das argilas no campo terapêutico tem aumentado, mostrando a relevância de pesquisas na área de medicamentos e materiais.

In recent decades the use of clay minerals in the areas of Materials Science and Engineering has received notable attention for its use in carrying of drugs. Among the various types of clay, and fibrous tubes have been used in the preparation of bionanocompósitos due to their inherent properties, for example high surface area. This research aimed a review at the literature of the use of tubular and fibrous clays for the carrying of drugs. The search for articles was conducted in the Web of Science database, using combination of terms: Fibrous Clay and drug delivery, Tubular Clay and drug delivery, Halloysite and drug delivery, imogolite and drug delivery, drug delivery and Palygoskite and Sepiolite and drug delivery. Found total of 36 articles during the search. It was observed that most of the clay articles used in combination with other materials (with formation of composites and blends), in particular polymers in order to extend the properties that improve the vectoring of active pharmaceutical ingredients (APIs), such as modification pore size, the pH, the binding energy between molecules, among others. Thus, it is clear that the interest in the use of clays in the therapeutic field has increased, showing the relevance of research in the area of drugs and materials.

Chitosan was modified with acetylacetone and ethylenediamine in the absence of solvent. The new biopolymer obtained from the modification was characterized by elemental analysis and NMR 13C and applied in the removal of diclofenac sodium aqueous solution varying the pH and time. Through elemental analysis was possible to verify a decreasing in C/N relation after reaction with acetylacetone and an increasing after modification with ethylenediamine. From NMR analysis was verified the appearance of peaks around 160-210 ppm in both materials due to free carbonyl groups in the first step of the modification, besides the formation of imine bonds. The adsorption tests showed that the highest value occurred at pH 4 and from the results of the kinetic study was found that maximum adsorption occurred within 45 minutes and experimental data adjusted better to linear adjustment, following pseudo second-order model. The results show a material efficient in the removal of emerging pollutants.

The palygorskite is an aluminum-magnesium silicate that has a fibrous morphology. Their physico-chemical characteristics are the result of high surface area, porosity and thermal resistance which make it an attractive adsorbent. Its adsorption capacity can be increased through chemical reactions and/or heat treatments. The objective of this work is to verify the effects of acid activation on the palygorskite, treated with HCl at 90 ºC at concentrations of 2, 4 and 6 mol L-1 in 2 and 4 hours, with clay/acid solution ratio 1 g 10 mL-1 and characterized by techniques: XRF, XRD and surface area. A significant increase in specific surface area was observed in the sample treated with HCl at the concentration 6 mol L-1. The changes were more pronounced at stricter concentrations of acidity, with decreasing intensity of reflection of the clay indicated in the XRD. These changes were confirmed in the XRF with the leaching of some oxides and with increasing concentration of SiO2.

Devido ao crescente interesse da população pelos tratamentos naturais, as argilas representam uma boa alternativa para a aceleração da cicatrização durante o tratamento de feridas. Dentre as argilas, a paligorsquita, uma argila piauiense, devido à sua composição com silício e alumínio, demonstra certa aplicabilidade farmacêutica como agente cicatrizante. O objetivo deste artigo é avaliar a ação cicatrizante da paligorsquita piauiense em sua forma natural e organofilizadas por meio da análise comparativa da macroscopia e dos exames histológicos em feridas cutâneas de ratos machos e fêmeas Wistar adultos com 2 meses de idade. Para tanto, foram realizadas tricotomia circular no corno dorsal dos ratos para verificar os efeitos dos tratamentos realizados com solução salina 0,9%, colagenase, paligorsquita natural, paligorsquita organofilizada por cloreto de cetiltrimetilamônio e paligorsquita organofilizada por cloreto de alquildimetilbenzilamônio. Para todas as argilas testadas foi feita a avaliação microbiológica pelo método de plaqueamento em profundidade e do método de estrias em superfície, bem como foi realizada após tratamento, a análise macroscópica das feridas cutâneas por meio organoléptico, medição em paquímetro e análise histológica. Por meio da avaliação microbiológica foi detectada a necessidade de esterilização da argila para posterior incorporação na forma farmacêutica. A análise macroscópica sugere que houve cicatrização da área lesionada, bem como a análise histológica demonstrou efeito benéfico após o uso tópico do material argiloso. Nossos dados sugerem que a paligorsquita pode exercer um maior efeito cicatrizante em relação aos demais tratamentos, embora após o término deste tratamento, todos os animais analisados apresentaram a mesma reparação tecidual.

In view of growing interest in natural treatments, clays would appear to be a good alternative for speeding up the healing process during the treatment of wounds. Of the various clays, palygorskite, a clay from the Brazilian State of Piauí, composed of silicon and aluminum, has shown itself to be pharmaceutically useful as a healing agent. The aim of this article is to evaluate the effect on the healing of wounds of Piauí palygorskite, both in its natural state and when organophilic, by way of comparative analysis of macroscopic and histological tests on skin wounds in adult male and female two-month-old Wistar rats. To this end, a circular trichotomy of the dorsal cornus of the rats was carried out to confirm the effects of treatments involving 0.9% saline solution, collagenase, natural palygorskite, organophilic palygorskite with cetyltrimethylammonium chloride, and organophilic palygorskite with alkyldimethylbenzylammonium chloride. The testing of all the clays involved microbiological evaluation using the depth of plaque and surface striation methods, along with post-treatment macroscopic analysis of skin wounds by way of organoleptics, pachymetry and histological analysis. Microbiological evaluation revealed the need for sterilization of the clay prior to incorporation in the pharmaceutical form. Macroscopic analysis suggests that healing of the wounded area occurred, and histological analysis showed the beneficial effect of the topical use of clay material. Our data suggest that palygorskite may be more powerful than other healing agents, although, on completing treatment, all the animals studied showed the same degree of tissue repair.