Electrochemical Studies of Magnesium Coated with Modified Chitosan and Electrosprayed as an Anticorrosive Protection Method in Bone Repair / Estudios Electroquímicos del Magnesio Recubierto con Quitosano Modificado y Electrorociado como Proceso de Protección Anticorrosiva en la Reparación de Hueso

ABSTRACT Magnesium (Mg) is essential for the metabolic reactions of the human body and is known for its biocompatibility, its mechanical and physical properties are similar to human bone, which is why it is considered to have high potential in biomedical applications such as temporary and resorbable implants. Through surface modifications, the high tendency to corrosion of Mg could be controlled, such as biodegradable membranes that prevent the passage of chloride ions present in the human organism. To prepare the membrane, solutions of chitosan modified with gelatin and/or glutaraldehyde are used and by means of the electrospray method applied to protect the Mg. To simulate body fluid conditions a Kokubo saline solution (BFK) was prepared. The study focuses on evaluating the corrosion rate of Mg with a coating made of a chitosan electrosprayed membrane, applying electrochemical measurements of electrochemical impedance spectroscopy and linear polarization resistance. The key additive to improve the behavior of the membranes was observed with the use of gelatin, where the membrane with the best results lowing corrosion rates is the Mg CH+GE+GL system, which it was observed with very good physical integrity in the images of morphological analyzes of the surface after 30 days of exposure.

RESUMEN El magnesio (Mg) es esencial para las reacciones metabólicas del cuerpo humano y es conocido por su biocompatibilidad, sus propiedades mecánicas y físicas son similares a las del hueso humano, por lo que se considera que tiene un alto potencial en aplicaciones biomédicas como implantes temporales y reabsorbibles. Mediante modificaciones superficiales se podría controlar la alta tendencia a la corrosión del Mg, como por ejemplo membranas biodegradables que impidan el paso de iones cloruro presentes en el organismo humano. Para preparar la membrana se utilizan soluciones de quitosano modificado con grenetina y/o glutaraldehído y mediante el método de electrorociado se aplican para proteger el Mg. Para simular las condiciones de los fluidos corporales se preparó una solución salina de Kokubo. El estudio se enfoca en evaluar la velocidad de corrosión del Mg con un recubrimiento hecho de una membrana electrorociada con quitosano, aplicando técnicas electroquímicas de espectroscopia de impedancia electroquímica y resistencia de polarización lineal. El aditivo clave para mejorar el comportamiento de las membranas se observó con el uso de gelatina, donde la membrana con mejores resultados bajando los índices de corrosión es el sistema Mg CH+GR+GL, el cual se observó con muy buena integridad física en las imágenes de análisis morfológicos de la superficie después de 30 días de exposición.

Bioactive coating of sodium alginate and agar added with essential oils of thyme (thymus vulgaris l.) and sweet orange (citrus aurantium var. dulcis) with antimicrobial properties applied over strawberries

Minimally processed strawberries have high acceptability but a short shelf life. The application of edible coatings with essential oils may be an alternative to preserve these fruits. Our objective was to develop, apply and characterize the effect of bioactive edible coatings based on agar or sodium alginate with thyme and/or sweet orange essential oils with antimicrobial properties, mainly against Listeria monocytogenes, for strawberries. The effect of the coatings on the physicochemical, microbiological, and sensory properties that determine the shelf life of strawberries was verified at 1, 8, and 15 days. The effect against Listeria monocytogenes bacteria in strawberries artificially contaminated with this microorganism was also evaluated. Thyme and sweet orange essential oils had thymol and D-limonene, respectively, as main components. Alginate coating with sweet orange and thyme essential oil showed the best results. For Listeria monocytogenes, the coating applied after fruit contamination had an antimicrobial effect.

Las fresas mínimamente procesadas tienen una alta aceptación, pero una vida útil corta. La aplicación de recubrimientos comestibles con aceites esenciales puede ser una alternativa para conservar estos frutos. El objetivo fue desarrollar, aplicar y caracterizar el efecto del uso de recubrimientos comestibles bioactivos, a base de agar agar o alginato de sodio, adicionados con aceites esenciales de tomillo y/o naranja dulce, con propiedades antimicrobianas, principalmente anti-Listeria monocytogenes sobre la fresa. Se verificó el efecto de los recubrimientos sobre las características fisicoquímicas, microbiológicas y sensoriales que determinan la vida útil de las fresas a 1, 8 y 15 días. También se evaluó el efecto contra la bacteria Listeria monocytogenes en fresas contaminadas artificialmente con este microorganismo. Los aceites esenciales de tomillo y naranja dulce presentaron timol y D-limoneno como compuestos mayoritarios, respectivamente. El recubrimiento de alginato con aceite esencial de naranja dulce y tomillo mostró los mejores resultados. Para Listeria monocytogenes, el recubrimiento aplicado después de la contaminación de la fruta tuvo un efecto antimicrobiano.

Calidad de frutos de pitahaya (Selenicereus mega/anthus Haw.) sometidos a diferentes recubrimientos durante el almacenamiento

R E S U M E N La pitahaya amarilla es susceptible a los daños mecánicos durante la vida en anaquel, lo que genera pérdidas económicas considerables, las cuales se pueden mitigar a través de la aplicación de ceras. Por lo anterior se evaluó el efecto de recubrimientos comestibles en la calidad poscosecha de frutos de pitahaya amarilla con el fin de mantener la calidad por más tiempo. Se empleó un diseño de tres tratamientos completamente aleatorizados (cerabrix, cera natural y testigo sin aplicación). Las aplicaciones de ceras en los frutos de pitahaya disminuyeron la pérdida de masa (PM) en promedio en un 21% durante el almacenamiento, especialmente el recubrimiento con cerabrix. La firmeza de los frutos disminuyó drásticamente a partir de los seis días después de cosecha (ddc), al pasar de 5I,2 a 7,3 N. Durante la poscosecha, los frutos de pitahaya mostraron un aumento en la intensidad respiratoria (IR) al pasar de 10,48 a 26,35 mg.kg-I.hI de CO2, además, el pH aumentó de 4,I3 a 5,I7, mientras que los los sólidos solubles totales (SST), la acidez total titulable (ATT) y la relación de madurez (RM) disminuyeron, no obstante, la aplicación de cerabrix mantuvo los valores más bajos de sólidos solubles totales (SST). Los frutos con aplicación de recubrimiento comestible presentaron al final del almacenamiento menores valores de luminosidad (L* = 62,6) con una tonalidad más oscura que los frutos sin aplicación (L*= 66,4), los cuales mantuvieron el color amarillo característico de la pitahaya. La aplicación de recubrimientos comestibles no afectó las características organolépticas de los frutos de pitahaya.

Yellow pitahaya is very susceptible to mechanical damage during shelf life, which generates considerable economic losses, which can be mitigated through the application of coats. Therefore, the effect of edible coatings on the postharvest quality of yellow pitahaya fruits was evaluated in order to maintain quality for longer. A completely randomized three-treatment design was used (cerabrix, natural wax and control without application) was used. Wax applications in pitahaya fruits decreased PM by an average of 2I% during storage, especially the cerabrix coating. The firmness of the fruits decreased drastically from six days after harvest, when going from 5I.2 to 7.3 N. During the postharvest, the pitahaya fruits showed an increase in IR when going from I0.48 to 26.35 mg.kg-I.hI of CO2, in addition, the pH increased from 4.I3 to 5.I7, while the TSS, TTA and MI decreased, however, the application of cerabrix maintained the lowest values of TSS. Fruits with edible coating application showed lower luminosity values at the end of storage (L* = 62.6) with a darker hue than fruits without application (L*= 66.4), which maintained the characteristic yellow color of the pitahaya. The application of edible coatings did not affect the organoleptic characteristics of pitahaya fruits.

A pitaia amarela é muito suscetível a danos mecânicos durante a vida de prateleira, o que gera perdas econômicas consideráveis, que podem ser mitigadas com a aplicação de demãos. Portanto, avaliou-se o efeito de revestimentos comestíveis na qualidade pós-colheita de frutos de pitaia amarela, a fim de manter a qualidade por mais tempo. Um desenho de três tratamentos completamente randomizado foi usado. (cerabrix, cera natural e controle sem aplicação). A aplicação de cera em frutos de pitaia reduziu o PM em média 21% durante o armazenamento, principalmente o revestimento de cerabrix. A firmeza dos frutos diminuiu drasticamente após seis dias após a colheita, ao passar de 5I,2 para 7,3 N. Durante a pós-colheita, os frutos de pitaia apresentaram aumento da IR ao passar de I0,48 para 26,35 mg.kg-I.hI de CO2, além disso, o pH aumentou de 4,I3 para 5,I7, enquanto o TSS, TTA e MI diminuíram, porém, a aplicação de cerabrix manteve os menores valores de TSS. Frutos com aplicação de revestimento comestível apresentaram menores valores de luminosidade ao final do armazenamento (L* = 62,6) com tonalidade mais escura do que frutos sem aplicação (L*= 66,4), que mantiveram a coloração amarela característica da pitaia. A aplicação de coberturas comestíveis não afetou as características organolépticas dos frutos de pitaiaia.

The Effect of Low Tidal Volume Ventilation on Inflammatory Cytokines During Cardiopulmonary Bypass

Abstract Introduction: Halting ventilation during cardiopulmonary bypass (CPB) is implemented to operate in a less bleeding setting. It sustains a better visualization of the operation area and helps to perform the operation much more comfortably. On the other hand, it may lead to a series of postoperative lung complications such as atelectasis and pleural effusion. In this study, we investigated the effects of low tidal volume ventilation on inflammatory cytokines during CPB. Methods: Twenty-eight patients undergoing cardiovascular surgery were included in the study. Operation standards and ventilation protocols were determined and patients were divided into two groups: patients ventilated with low tidal volume and non-ventilated patients. Plasma samples were taken from patients preoperatively, perioperatively from the coronary sinus and postoperatively after CPB. IL-6, IL-8, TNF-α and C5a levels in serum samples were studied with enzyme-linked immunosorbent assay (ELISA) kits. Results: C5a, IL-6, IL-8 and TNF-α were similar when compared to the low tidal volume ventilated and non-ventilated groups (P>0.05) Comparing the groups by variables, IL-6 levels were increased during CPB in both groups (P=0.021 and P=0.001), and IL-8 levels decreased in the ventilation group during CPB (P=0.018). Conclusion: Our findings suggest that low tidal volume ventilation may reduce the inflammatory response during CPB. Although the benefit of low tidal volume ventilation in CPB has been shown to decrease postoperative lung complications such as pleural effusion, atelectasis and pneumonia, we still lack more definitive and clear proofs of inflammatory cytokines encountered during CPB.

In-vitro evaluation of the anti-cariogenic effect of a hybrid coating associated with encapsulated sodium fluoride and stannous chloride in nanoclays on enamel

Abstract Objective The aim of this study is to test, in vitro, the anti-cariogenic effect of experimental hybrid coatings, with nano clays of halloysite or bentonite, loaded with sodium fluoride or with a combination of sodium fluoride and stannous chloride, respectively. Methodology The varnish Fluor Protector (1,000 ppm of F-) was used as positive control and no treatment was the negative control. Enamel specimens (5 mm × 5 mm) were obtained from bovine teeth. The specimens (n=10) had their surfaces divided into two halves (5 mm × 2.5 mm each), in which one half received one of the treatments (Hybrid; Hybrid + NaF; Hybrid + NaF + SnCl2; Hybrid + NaF Loaded; Hybrid + NaF + SnCl2 Loaded). The specimens were submitted to a cariogenic challenge using a biofilm model (S. mutans UA159, for 5 days). Enamel surfaces both under and adjacent to the treated area were analyzed for mineral loss and lesion depth, by transverse microradiography. The pH of the medium was measured twice a day, and the fluoride release was analyzed. Additional specimens were submitted to confocal analysis. Results Data were statistically analyzed by two-way ANOVA followed by Tukey test (α=0.05). None of hybrid groups were able to reduce the lesion depth; the Hybrid + NaF group, however, was able to reduce mineral loss differing from the negative control (p=0.008). The groups showed no significant difference in the pH measurement and fluoride release. Confocal analysis confirmed that for all groups the biofilm growth was similar. Conclusion None of the hybrid groups reduced lesion depth, but the Hybrid + NaF group was able to promote protection against mineral loss.

Advances in Polymer Hydrophilic Lubricating Coatings for Medical Catheters / 中国医疗器械杂志

Polymer hydrophilic lubricating coatings for medical catheters refer to highly hydrophilic coating films fixed on the surface of catheters with binding force, which can reduce the surface friction with human tissues during the use of interventional catheters, improve the patient comfort of and effectively reduce the incidence of infection. Based on the development process of medical catheter coating, this review summarizes recent advances in the field of polymer hydrophilic lubricating coatings for medical catheters from types of hydrophilic coating polymer, development of coating technology and establishment of coating performance evaluation method. Main problems in this field are analyzed and development trends in the future are prospected.

Determination of bisphosphonates anti-resorptive properties based on three forms of ceramic materials:Sorption and release process evaluation / 药物分析学报

There is a strong need to search for more effective compounds with bone anti-resorptive properties,which will cause fewer complications than commonly used bisphosphonates.To achieve this goal,it is necessary to search for new techniques to characterize the interactions between bone and drug.By studying their interaction with hydroxyapatite (HA),this study used three forms of ceramic materials,two of which are bone-stimulating materials,to assess the suitability of new active substances with anti-resorptive properties.In this study,three methods based on HA in loose form,polycaprolactone/HA (a polymer-ceramic materials containing HA),and polymer-ceramic monolithic in-needle extraction(MINE) device (a polymer inert skeleton),respectively,were used.The affinity of risedronate (a standard compound) and sixteen aminomethylenebisphosphonates (new compounds with potential anti-resorptive properties) to HA was defined according to the above-mentioned methods.Ten monolithic materials based on 2-hydroxyethyl methacrylate/ethylene dimethacrylate are prepared and studied,of which one was selected for more-detailed further research.Simulated body fluids containing bisphosphonates were passed through the MINE device.In this way,sorption-desorption of bisphosphonates was evaluated using this MINE device.The paper presents the advantages and disad-vantages of each technique and its suitability for assessing new active substances.All three methods allow for the selection of several compounds with potentially higher anti-resorptive properties than risedronate,in hope that it reflects their higher bone affinity and release ability.

Efecto antimicrobiano sobre Streptococcus mutans de sistema adhesivo con nanopartículas de óxido de zinc y cobre / Antimicrobial effect against Streptococcus mutans of an adhesive system with copper and zinc oxide nanoparticles

Objetivo: Determinar las propiedades antimicrobianas de la incorporación de nanopartículas de óxido de zinc y cobre en un adhesivo de grabado y lavado total sobre Streptococcus mutans en pacientes con restauraciones de resina compuesta confeccionadas con adhesivo cargado. Métodos: Este estudio clínico randomizado, participaron 25 pacientes, de ambos sexos, pertenecientes al posgrado de Ortodoncia de la Facultad de Odontología de la Universidad de Chile, en los cuales se confirmó presencia de Streptococcus mutans en saliva. Se confeccionaron restauraciones de resina compuesta oclusales, en premolares superiores con indicación de exodoncia por el tratamiento de ortodoncia, con adhesivo cargado (cuya composición es 5 / 0.2 por ciento ZnO y Cu respectivamente) y control (sin presencia de nanopartículas en su composición), según el listado de aleatorización. Se tomaron muestras microbiológicas en tres tiempos con la Técnica de la cubeta (antes, 1 semana y 4 semanas posterior a la confección de las restauraciones). Se obtuvieron, aislaron e identificaron colonias de Streptococcus mutans a partir de las muestras obtenidas. Los datos fueron analizados por el test de Mann Whittney. Resultados: El promedio del recuento de UFC (unidades formadoras de colonias) de Streptococcus mutans en el grupo experimental fue mayor posterior a la confección de las restauraciones de resina compuesta.Los resultados de la identificación molecular por PCR demuestran la presencia de Streptococcus mutans en 20 de 25 muestras. Conclusiones: No existen diferencias en el recuento de Streptococcus mutans antes y después de la aplicación del adhesivo sobre las restauraciones de resina compuesta(AU)

Objective: Determine the antimicrobial properties of the incorporation of copper and zinc oxide nanoparticles into a total rinse and etch adhesive against Streptococcus mutans in patients with composite resin restorations made with loaded adhesive. Methods: A randomized clinical study was conducted of 25 patients of both sexes from the orthodontics graduate course taught at the Dental School of the University of Chile, in whom the presence of Streptococcus mutans was confirmed in saliva. Occlusal composite resin restorations were performed in upper premolars with exodontia indicated as part of the orthodontic treatment, using loaded adhesive (composition 5 / 0.2 percent ZnO and Cu, respectively) and control (without nanoparticles in its composition), according to the randomization list. Microbiological samples were taken at three moments applying the tray technique (before, 1 week after and 4 weeks after the restorations). Streptococcus mutans were obtained, isolated and identified from the samples taken. Data analysis was based on the Mann-Whitney test. Results: Mean Streptococcus mutans CFU count in the experimental group was higher after the composite resin restorations were made. Results of PCR molecular identification show the presence of Streptococcus mutans in 20 of 25 samples. Conclusions: No differences were found in the Streptococcus mutans count before and after application of the adhesive over the composite resin restorations(AU)

Polymer blend: a new approach for eliminating curing effect of aqueous dispersion coatings

The aim of present work was to investigate blends of Eudragit® NE 30D with Aquacoat® ECD using different ratios to eliminate curing effect associated with individual polymers. Propranolol HCl 10% w/w was layered onto sugar cores using 5% w/w HPMC as a binder. Drug-layered-cores were coated either with pure or blends of Aquacoat® ECD: Eudragit® NE 30D in a fluidized bed coater to obtain 20% w/w coating level. Talc 35% w/w was used as anti-tacking agent. The pellets were characterized for in vitro dissolution studies, morphology, water uptake-weight loss, osmolality and adhesion of coating after curing at 60 °C or 60 °C/75% RH for 24 h. The findings revealed that Aquacoat® ECD coated pellets showed curing effect due to further gradual coalescence of polymeric particles which resulted into better film formation upon curing. In contrast, the curing effect of Eudragit® NE 30D coated pellets was caused by decrease in adhesion of coatings after curing which provided entirely different swelling behavior of uncured (localized swelling) and cured (uniform swelling) pellets. The undesired curing effect of individual polymers was eliminated by using their blends in appropriate ratio.

Efecto de recubrimientos comestibles de Aloe vera y alginato de sodio sobre la calidad poscosecha de fresa / Effect of Aloe vera and sodium alginate edible coatings on postharvest quality of strawberry

RESUMEN Las fresas son frutas altamente perecederas, susceptibles a daño mecánico, deterioro y desórdenes fisiológicos durante su almacenamiento. La aplicación de recubrimientos, se presenta como una alternativa promisoria de tratamiento poscosecha, que permite mantener la calidad de las fresas. El objetivo de esta investigación fue estudiar el efecto de recubrimientos comestibles de sábila (A. vera) y alginato de sodio sobre parámetros de calidad de fresas, durante el almacenamiento refrigerado. Se evaluaron mezclas de recubrimientos comestibles de alginato de sodio y A. vera (100:0, 75:25, 50:50 y 25:75) sobre la pérdida de peso, color, firmeza, pH y acidez titulable de fresas, durante almacenamiento refrigerado (0, 3 ,9 y 12 días). Adicionalmente, se determinó el espesor y la opacidad de las películas obtenidas a partir de las soluciones formadoras de recubrimientos, utilizando el método de "casting". Los resultados mostraron que la combinación de A. vera y alginato de sodio tiene un efecto significativo en la reducción de pérdida de calidad de fresa, durante el almacenamiento en refrigeración. Todos los tratamientos con recubrimientos comestibles presentaron, al final del almacenamiento, menor pérdida de peso (7-16%), mayor firmeza (entre 1,3 a 2,1 veces más), mayor retención del color y mayor acidez titulable que las muestras sin recubrimiento (control). El espesor de las películas disminuyó con el incremento de la adición de Aloe vera y la opacidad disminuyó significativamente con la adición de la sábila en 25% y 50% en las mezclas con alginato de sodio.

ABSTRACT Strawberries are highly perishable fruits, being susceptible to mechanical injury, decay and physiological disorders during storage. Applications of edible coatings have been shown to be promising as a tool to improve the quality and extend storage. The aim of this study was to evaluate the use of Aloe vera and sodium alginate as an edible coating in postharvest quality of cold storage strawberries. The composition of edible coatings of sodium alginate and A. vera (100: 0, 75:25, 50:50 and 25:75) was studied on weight loss, color, firmness, pH and titrable acidity of strawberries during refrigerated storage (0, 3, 9 and 12 days). The thickness and opacity of the films were also determined, from the coating forming solutions using the casting method. The short shelf life and the high deterioration of the quality characteristics of strawberries during postharvest, justify to investigate alternative conservation techniques such as edible coatings, in order to reduce food loss and improve consumer acceptance The results showed that the combination of Aloe vera and sodium alginate has a significant effect in the reduction of the loss of the quality of the fruit during refrigerated storage. All coating treatments showed at the end of storage less weigth loss (7-16%), greater firmness, (between 1,3 to 2,1 more times) more color retention and greater titrable acidity tan uncoated samples (Control). The addition of Aloe vera decreased the thickness of the films and the opacity decreased significantly with the addition of Aloe vera in 25 and 50% in the mixtures with sodium Alginate.

Comparative analysis of myocardial protection with htk solution and hypothermic hyperkalemic blood solution in the correction of acyanogenic congenital cardiopathies - a randomized study

Abstract Objective: The goal of the present study was to compare the myocardial protection obtained with histidine-tryptophan-ketoglutarate (HTK) cardioplegic solution (Custodiol®) and with intermittent hypothermic blood solution. Methods: Two homogenous groups of 25 children with acyanotic congenital heart disease who underwent total correction with mean aortic clamping time of 60 minutes were evaluated in this randomized study. Troponin and creatine kinase-MB curves, vasoactive-inotropic score, and left ventricular function were obtained by echocardiogram in each group. The values were correlated and presented through graphs and tables after adequate statistical treatment. Results: It was observed that values of all the studied variables varied over time, but there was no difference between the groups. Conclusion: We conclude that in patients with acyanotic congenital cardiopathies submitted to total surgical correction, mean aortic clamping time around one hour, and cardiopulmonary bypass with moderate hypothermia, the HTK crystalloid cardioplegic solution offers the same myocardial protection as the cold-blood hyperkalemic cardioplegic solution analyzed, according to the variables considered in our study model.

In vitro antimicrobial effect of bioadhesive oral membrane with chlorhexidine gel

Abstract This study aimed to evaluate in vitro the antimicrobial effect of a bioadhesive chitosan-based oral membrane with chlorhexidine for local treatment of infections in the oral tissues. Five oral membranes of different compositions were tested: 5% chitosan (G1); 5% chitosan ± 0.2% chlorhexidine (G2), 5% chitosan ± 0.6% chlorhexidine (G3), 5% chitosan ± 1.0% chlorhexidine (G4), and 5% chitosan ± 2.0% chlorhexidine (G5). Also, five gel types were tested according to the following compositions: 5% chitosan gel (G6), 0.2% chlorhexidine gel (G7), 2.0% chlorhexidine gel (G8), 5% chitosan gel ± 0.2% chlorhexidine gel (G9), and 5% chitosan gel ± 2.0% chlorhexidine gel (G10). The antimicrobial action of the samples was tested against Candida albicans and Streptococcus mutans through antibiogram by measuring the inhibition halos. Data were statistically analyzed by Kruskal-Wallis and one-way ANOVA followed by Tukey test (p<0.05). The 2.0% chlorhexidine membrane (G5) and the disks containing 2.0% chlorhexidine gel (G8) showed the greatest inhibition halos for both microorganisms, with statistically significant difference when compared to others tested groups (p=0.008) only for Candida albicans inhibitions results. All the other formulations of membranes and gels showed inhibition halos, but without statistically significant difference. The bioadhesive chitosan-based oral membrane with 2% chlorhexidine and 2% chlorhexidine gel were the most effective in inhibiting the tested microorganisms.

Resumo O objetivo deste estudo foi avaliar in vitro o efeito antimicrobiano de uma bandagem oral bioadesiva de quitosana com clorexidina para o tratamento de infecções dos tecidos orais. Cinco bandagens de diferentes composições foram testadas: Quitosana 5% (G1); Quitosana 5% ± clorexidina a 0,2% (G2), Quitosana 5% ± clorexidina a 0,6% (G3), Quitosana 5% ± clorexidina a 1,0% (G4) e Quitosana 5% ± clorexidina a 2,0% (G5). Foram testados também 5 tipos de géis nas seguintes composições: Gel de Quitosana 5% (G6), Gel de clorexidina a 0,2% (G7), Gel de clorexidina a 2,0% (G8), Gel de Quitosana 5% ± clorexidina a 0,2% (G9) e Gel de Quitosana 5% ± clorexidina a 2,0% (G10). A ação antimicrobiana das amostras foi testada contra Candida albicans e Streptococcus mutans por meio do antibiograma, medindo o halo de inibição. Os dados foram analisados pelo teste de Kruskal-Wallis e ANOVA a um critério seguido pelo teste de Tukey (p<0,05). A membrana com 2,0% de clorexidina (G5) e os discos contendo gel com 2,0% de clorexidina (G8) apresentaram os maiores halos de inibição para os dois microrganismos, com diferença estatisticamente significativa em relação aos demais grupos testados (p=0,008) apenas nos resultados de inibição de C. albicans. Todas as outras formulações de membranas e géis apresentaram halo de inibição, mas sem diferença estatisticamente significativa. A bandagem oral bioadesiva de quitosana com gel de 2% de clorexidina foi a mais efetiva em inibir os microrganismos testados.

Embalagens para alimentos: tendências e inovações / Food Packaging: trends and innovations

A embalagem do alimento têm por funções conter, proteger, comunicar e conferir conveniência, nas etapas de armazenamento e distribuição. É também veículo de informação, apresentando instruções de manuseio, composição nutricional e rotulagem. Com o desenvolvimento da tecnologia, surgem novas forma de apresentação e embalagem de alimentos, visando aumento na vida de prateleira e maior praticidade. Nesse contexto o trabalho trata de uma pesquisa documental indireta por meio de fontes bibliográficas e documentos, para delinear as principais tendências e inovações em embalagens de alimentos. Há interesse e investimentos em embalagens "ativas" e "inteligentes" as quais interagem diretamente com o produto, e também os revestimentos comestíveis, com enfoque na biodegradabilidade.(AU)

Liposomal Microencapsulation of Rodent-repelling Agents onto Jute Burlaps: Assessment of Cytotoxicity and Rat Behavioral Test.

In Egypt, the world’s biggest wheat importer, about 7 to 10 percent of stored grains are damaged because of poor conditions of storage. Rodent invasion is considered as one of the main reasons that caused wheat grain damage. With respect of food safety, this work aims to treat the grain burlaps (containers) to rodent repellent. The rodent repellent agents was extracted from natural local resources. For the rodent repellent effectiveness, wheat burlaps are treated with rodent repelling agents using eco-friendly components. There are prepared using camphor oil, mint oil, and capsaicinoids (extracted from hot red pepper) as local resources to develop low cost and high-performance final product. The plan of work relies on two main axes; first, the experimental part in which burlap was treated for rodent repellent; second, testing and characterizing the treated samples for cytotoxicity and animal behavior test. The treatment was taking place by conventional pad-dry-cure technique.

Antimicrobial activity of chitosan coatings and films against Listeria monocytogenes on black radish / Actividad antimicrobiana de coberturas y películas de quitosano contra Listeria monocytogenes en rábano negro

The antibacterial activity of chitosan coatings prepared with acetic or lactic acid, as well as of composite chitosan-gelatin films prepared with essential oils, was evaluated in fresh shredded black radish samples inoculated with Listeria monocytogenes ATCC 19115 and L. monocytogenes ATCC 19112 during seven days of storage at 4 °C. The chitosan coating prepared with acetic acid showed the most effective antibacterial activity. All tested formulations of chitosan films exhibited strong antimicrobial activity on the growth of L. monocytogenes on black radish, although a higher inhibition of pathogens was achieved at higher concentrations of chitosan. The antimicrobial effect of chitosan films was even more pronounced with the addition of essential oils. Chitosan-gelatin films with thyme essential oils showed the most effective antimicrobial activity. A reduction of 2.4 log10 CFU/g for L. monocytogenes ATCC 19115 and 2.1 log10 CFU/g for L. monocytogenes ATCC 19112 was achieved in the presence of 1% chitosan film containing 0.2% of thyme essential oil after 24 h of storage.

Se evaluó la actividad antimicrobiana de coberturas del quitosano y de películas compuestas de quitosano-gelatina en muestras frescas de rábano negro cortado inoculadas con las cepas de Listeria monocytogenes ATCC 19115 y ATCC 19112, almacenadas durante 7 días a 4 °C. Las primeras fueron preparadas con ácido acético o ácido láctico, las segundas con aceites esenciales. Las coberturas de quitosano preparadas con ácido acético mostraron la actividad antimicrobiana más eficaz. Todas las formulaciones de películas de quitosano exploradas mostraron una fuerte actividad antimicrobiana sobre el crecimiento de L. monocytogenes, aunque la mayor inhibición de estos patógenos se logró con las mayores concentraciones de quitosano. La actividad antimicrobiana de las películas de quitosano fue mayor con la adición de aceite esencial. Las películas de quitosano-gelatina con aceite esencial del tomillo fueron las que mostraron la actividad antimicrobiana más eficiente. A las 24 h de almacenamiento, la película con 1% de quitosano y 0,2% de aceite esencial de tomillo produjo una reducción de 2,4 log10 UFC/g en L. monocytogenes ATCC 19115, y de 2,1 log10 UFC/g en L. monocytogenes ATCC 19112.

Sustainable Management of Keratin Waste Biomass: Applications and Future Perspectives

Keratin is a durable, fibrous protein which is mainly present in higher vertebrates (mammals, birds and reptiles) and humans epithelial cells. Food industry especially the meat market, slaughter house and wool industry produces million of tons of keratin containing biomass. These industries are constantly growing and the major producers include USA, Brazil and China, account for more than 40 million tons per year. These proteins constitute keratin by-products have from 15 to 18% nitrogen, 2-5% sulphur, 3.20% mineral elements and 1.27% fat and 90% of proteins. The organic waste rich in keratin can be utilized as a natural source using chemical and mechanical methods. The natural keratin obtained by biomass does not contain any harmful chemical and can be used directly to produce variety of cosmetics, creams, shampoos, hair conditioners and biomedical products. The natural protein is more compatible to use or apply on human skin and hairs. The monomeric units of natural keratin can penetrate in the skin and hair cuticle and able to nourish the skin without any side effects. In the present review various strategies for the purification and separation of keratin from the organic waste have been described and use of natural keratin in cosmetics and pharmaceutical industry has also been explored.

The osteointergration and osteoinduction of titanium implant with nHA/BG gradient coating in rabbits / 实用口腔医学杂志

Objective: To investigate the osteointegration and osteoinduction of nano hydroxyapatite/bioglass ( nHA/BG ) gradient nanofilm on the surface of titanium ( Ti) prepared by hypotherm sintering and plastic deformation. Methods:Hypotherm sintering was used to produce nHA/BG gradient coating followed by soaking in the simulated body fluid. Ti implants with gradient coatings were planted in femoral condyles at one side of 12 New Zealand rabbits and the untreated Ti implants were planted at the other side as the controls. 1, 3 and 6 months after implantation, the animals were sacrificed after X-ray examination and the tissues around the implants from the 3 month group were used for the preparation of hard tissue section and ground section. New bone formation was observed by tetracycline fluorescence staining. Von Gieson staining was used to observe the osteointegration at the interface between bone and im-plant. Results:The gradient coatings were porous and composed of irregular rod-like nano-HA crystals. Animal study showed well es-tablished osteointegration between the gradient coating and more novel bone was found around the implants with gradient coatings. Conclusion:Osteointegration and ostioinduction of Ti implant can be enhanced by nanostructured surface with gradient coatings of nHA/BG.

The impact of storage conditions upon gentamicin coated antimicrobial implants☆ / 药物分析学报

A systematic approach was developed to investigate the stability of gentamicin sulfate (GS) and GS/poly (lactic-co-glycolic acid) (PLGA) coatings on hydroxyapatite surfaces. The influence of environmental factors (light, humidity, oxidation and heat) upon degradation of the drug in the coatings was investigated using liquid chromatography with evaporative light scattering detection and mass spectrometry. GS coated rods were found to be stable across the range of environments assessed, with only an oxidizing atmosphere resulting in significant changes to the gentamicin composition. In contrast, rods coated with GS/PLGA were more sensitive to storage conditions with compositional changes being detected after storage at 60 °C, 75%relative humidity or exposure to light. The effect of γ-irradiation on the coated rods was also investigated and found to have no significant effect. Finally, liquid chromatography–mass spectrometry analysis revealed that known gentamines C1, C1a and C2 were the major degradants formed. Forced degradation of gentamicin coatings did not produce any unexpected degradants or impurities.

Adhesión convencional en dentina, dificultades y avances en la técnica / Conventional dentin bonding. Difficulties and progress in the technique

INTRODUCCIÓN: estudios respecto a la adhesión en dentina han reportado que, contrario a la estabilidad lograda sobre esmalte dental, en dentina los mecanismos adhesivos todavía son sensibles, impredecibles e inestables. El objetivo de este trabajo es revisar la literatura actual sobre la adhesión en dentina, con el fin de caracterizar la adhesión convencional describiendo las modificaciones actuales del protocolo convencional, encaminadas a mejorar el desempeño adhesivo de los materiales dentales. Métodos: se hizo una revisión de la literatura evaluando 3 bases de datos: ScienceDirect, Springer y Medline, de las cuales se escogieron los 52 artículos más relevantes, publicados entre los años 2004 y 2013. Se usaron, como criterios de búsqueda, las palabras clave: dentin, dentin bonding, bond strength y acid etching. Resultados: al revisar los artículos seleccionados, se logró una descripción del protocolo de adhesión convencional que muestra la formación del barrillo dentinario (smear layer), la acción del ácido fosfórico y la formación de la interfase adhesiva propiamente dicha, junto con las dificultades propias de la técnica y las posibles soluciones planteadas hasta la fecha. Conclusión: la adhesión convencional sobre dentina es un procedimiento estricto y delicado, que evidencia inconvenientes como la degradación hidrolítica y proteolítica de la matriz de colágeno por parte de enzimas liberadas en el momento de la desmineralización, lo que deteriora la interfase adhesiva. Por tanto, se han sugerido sustancias que pueden ser utilizadas como agentes de protección del colágeno, sin alterar e incluso mejorando la resistencia adhesiva.

INTRODUCTION: studies on dentin bonding have reported that, contrary to the achieved stability on dental enamel, adhesive mechanisms on dentine are still sensitive, unpredictable, and unstable. The objective of this study is to review the current literature on dentin bonding in order to characterize conventional bonding, describing current modifications of the conventional protocol aimed at improving the adhesive performance of dental materials. METHODS: a literature review was conducted within 3 databases: ScienceDirect, Springer, and Medline, choosing the 52 most relevant articles published between 2004 and 2013. The following key words were used as search criteria: dentin, dentin bonding, bond strength, and acid etching. RESULTS: the review of the selected articles provided a description of the conventional adhesion protocol showing the formation of smear layer, the action of phosphoric acid, and the actual formation of adhesive interface, as well as the difficulties of the technique and possible solutions suggested to date. CONCLUSIONS: conventional dentin bonding is a precise and delicate procedure that shows disadvantages such as the hydrolytic and proteolytic degradation of collagen matrix by enzymes released at the time of demineralization, which damages the adhesive interface. Therefore, several substances have been suggested to be used as agents of collagen protection without altering adhesive strength, and even improving it.studies on dentin bonding have reported that, contrary to the achieved stability on dental enamel, adhesive mechanisms on dentine are still sensitive, unpredictable, and unstable. The objective of this study is to review the current literature on dentin bonding in order to characterize conventional bonding, describing current modifications of the conventional protocol aimed at improving the adhesive performance of dental materials. Methods: a literature review was conducted within 3 databases: ScienceDirect, Springer, and Medline, choosing the 52 most relevant articles published between 2004 and 2013. The following key words were used as search criteria: dentin, dentin bonding, bond strength, and acid etching. Results: the review of the selected articles provided a description of the conventional adhesion protocol showing the formation of smear layer, the action of phosphoric acid, and the actual formation of adhesive interface, as well as the difficulties of the technique and possible solutions suggested to date. Conclusion: conventional dentin bonding is a precise and delicate procedure that shows disadvantages such as the hydrolytic and proteolytic degradation of collagen matrix by enzymes released at the time of demineralization, which damages the adhesive interface. Therefore, several substances have been suggested to be used as agents of collagen protection without altering adhesive strength, and even improving it.