Development of Graphene Oxide Composite Aerogel with Proanthocyanidins with Hemostatic Properties As a Delivery System.

The graphene aerogels' potential for use as both a hemostatic agent and dermal delivery system has scarcely been investigated. In this study, we used a sol-gel process for generating dry and stable composite aerogels based on graphene oxide (GO) and poly(vinyl alcohol) (PVA). Furthermore, we incorporated natural extract of País grape seed (SD) and skin (SK), rich in proanthocyanidins (PAs or condensed tannins). The effect of the incorporation of the grape extracts was investigated in relation to the aerogels' structure, coagulation performance and the release of the extracts. The results demonstrated that they have a porous structure and low density, capable of absorbing water and blood. The incorporation of 12% (w/w) of PA extracts into the aerogel increased the negative zeta potential of the material by 33% (-18.3 ± 1.3 mV), and the coagulation time was reduced by 37% and 28% during the first 30 and 60 s of contact between the aerogel and whole blood, respectively. The release of extracts from the GO-PVA-SD and GO-PVA-SK aerogels was prolonged to 3 h with 20%, probably due to the existence of strong binding between PAs andGO-PVA, both characterized by the presence of aromatic and hydroxyl groups that can form noncovalent bonds but are strong and stable enough to avoid a greater release into the medium. This study provides a new GO-based aerogel, which has a great potential use in the field of dermal delivery, wound healing and/or the treatment of trauma bleeding.

[Pediculicide effect of a Eucaliptus globulus L formulation]. / Efecto pediculicida de una formulación en base a Eucaliptus globulus L.

INTRODUCTION: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide. OBJECTIVE: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus. METHOD: Through bioassays active concentrations ranges of the essential oil were established, and proceeded to develop a standardized, stable, pharmaceutical form, evaluating its effects on our population. RESULTS: The results showed 100% effectiveness; short time of death, ovicidal action, activity on the adhesion of the egg, and low toxicity. DISCUSSION: In addition to great effect, the inability of the parasite to become resistant to the chemical composition of the essential oil makes this formulation an alternative to the problem of head lice solution.

Efecto pediculicida de una formulación en base a Eucaliptus globulus L / Pediculicide effect of a Eucaliptus globulus L formulation

Introduction: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide. Objective: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus. Method: Through bioassays active concentrations ranges of the essential oil were established, and proceeded to develop a standardized, stable, pharmaceutical form, evaluating its effects on our population. Results: The results showed 100% effectiveness; short time of death, ovicidal action, activity on the adhesion of the egg, and low toxicity. Discussion: In addition to great effect, the inability of the parasite to become resistant to the chemical composition of the essential oil makes this formulation an alternative to the problem of head lice solution.

Introducción: La pediculosis capitis es un problema de salud pública con una alta prevalencia. La aparición de resistencia del parásito a los pediculicidas convencionales es de gran preocupación a nivel mundial. Objetivo: Desarrollar alternativas pediculicidas, efectivas y seguras, en base al aceite esencial de Eucaliptus globulus. Método: A través de bioensayos se establecieron rangos de concentraciones activas del aceite esencial, y se procedió al desarrollo de una forma farmacéutica, estandarizada, estable, evaluando sus efectos en nuestra población. Resultados: Los resultados mostraron 100% de efectividad; corto tiempo de muerte, acción ovicida, actividad sobre la adherencia del huevo, y baja toxicidad. Discusión: Además de la gran efectividad, la imposibilidad del parásito de adquirir resistencia a la composición química del aceite esencial hace de esta formulación una solución alternativa al problema de la pediculosis.

Beta-amyloid (Abeta40, Abeta42) binding to modified LDL accelerates macrophage foam cell formation.

Apart from its role as a risk factor in arteriosclerosis, plasma cholesterol is increasingly recognized to play a major role in the pathogenesis of Alzheimer's disease (AD). Moreover, alterations of intracellular cholesterol metabolism in neuronal and vascular cells are of considerable importance for the understanding of AD. Cellular cholesterol accumulation enhances the deposition of insoluble beta-amyloid peptides, which is considered a hallmark in the pathogenesis of AD. In order to test the hypothesis, whether exogenous beta-amyloid peptides (Abeta42, Abeta40) might contribute to cellular cholesterol accumulation by opsonization of lipoproteins, we compared the binding and uptake of native LDL, enzymatically modified LDL (E-LDL), copper oxidized LDL (Ox-LDL) and HDL as control, preincubated either in the absence or presence of Abeta42 or Abeta40, by human monocytes or monocyte-derived macrophages. Incubation of monocytes and macrophages with Abeta-lipoprotein-complexes lead to increased cellular free and esterified cholesterol when compared to non-opsonized lipoproteins, except for HDL. Furthermore, the cellular uptake of these complexes regulated Abeta-receptors such as FPRL-1 or LRP/CD91. In summary, our results suggest that Abeta42 and Abeta40 act as potent opsonins for LDL, E-LDL and Ox-LDL and enhance cellular cholesterol accumulation as well as Abeta-deposition in vessel wall macrophages.

Biological significance of DNA adducts investigated by simultaneous analysis of different endpoints of genotoxicity in L5178Y mouse lymphoma cells treated with methyl methanesulfonate.

The biological significance of DNA adducts is under continuous discussion because analytical developments allow determination of adducts at ever lower levels. Central questions refer to the biological consequences of adducts and to the relationship between background DNA damage and exposure-related increments. These questions were addressed by measuring the two DNA adducts 7-methylguanine (7-mG) and O(6)-methyl-2'-deoxyguanosine (O(6)-mdGuo) by LC-MS/MS in parallel to two biological endpoints of genotoxicity (comet assay and in vitro micronucleus test), using large batches of L5178Y mouse lymphoma cells treated with methyl methanesulfonate (MMS). The background level of 7-mG was 1440 adducts per 10(9) nucleotides while O(6)-mdGuo was almost 50-fold lower (32 adducts per 10(9) nucleotides). In the comet assay and the micronucleus test, background was in the usual range seen with smaller batches of cells (2.1% Tail DNA and 12 micronuclei-containing cells per 1000 binucleated cells, respectively). For the comparison of the four endpoints for dose-related increments above background in the low-response region we assumed linearity at low dose and used the concept of the "doubling dose", i.e., we estimated the concentration of MMS necessary to double the background measures. Doubling doses of 4.3 and 8.7microM MMS were deduced for 7-mG and O(6)-mdGuo, respectively. For doubling the background measures in the comet assay and the micronucleus test, 5 to 15-fold higher concentrations of MMS were necessary (45 and 66microM, respectively). This means that the contribution of an increase in DNA methylation to biological endpoints of genotoxicity is overestimated. For xenobiotics that generate adducts without background, the difference is even more pronounced because the dose-response curve starts at zero and the limit of detection of an increase is not affected by background variation. Consequences for the question of thresholds in dose-response relationships and for the setting of tolerable exposure levels are discussed.

High throughput quantification of cholesterol and cholesteryl ester by electrospray ionization tandem mass spectrometry (ESI-MS/MS).

Analysis of free cholesterol (FC) is not well suited for electrospray ionization (ESI); however, cholesteryl ester (CE) form ammonium adducts in positive ion mode and generate a fragment ion of m/z 369 upon collision-induced fragmentation. In order to allow parallel analysis of FC and CE using ESI tandem mass spectrometry (ESI-MS/MS), we developed an acetyl chloride derivatization method to convert FC to cholesteryl acetate (CE 2:0). Derivatization conditions were chosen to provide a quantitative conversion of FC to CE 2:0 without transesterification of naturally occurring CE species. FC and CE were analyzed by direct flow injection analysis using a fragment of m/z 369 in a combination of selected reaction monitoring (SRM) and precursor ion scan for FC and CE, respectively. Quantification was achieved using deuterated D(7)-FC and CE 17:0/CE 22:0 as internal standards as well as calibration lines generated by addition of FC and naturally occurring CE species to the respective sample matrix. The developed assay showed a precision and detection limit sufficient for routine analysis. A run time of 1.3 min and automated data analysis allow high throughput analysis. Loading of human skin fibroblast and monocyte derived macrophages with stable isotope labeled FC showed a potential application of this method in metabolism studies. Together with existing mass spectrometry methodologies for lipid analysis, the present methodology will provide a useful tool for clinical and biochemical studies and expands the lipid spectrum that can be analyzed from one lipid sample on a single instrumental platform.

Time-dependent effects of sodium arsenite on DNA breakage and apoptosis observed in the comet assay.

To assess genotoxic effects of sodium arsenite (NaAsO2) the single-cell gel electrophoresis (comet assay) had been conducted in various studies indicating genotoxicity. However, DNA fragmentation due to NaAsO2-induced apoptosis may constitute a bias in the interpretation of the results. Apoptotic cells can show typically large and diffuse comets, which are usually excluded during genotoxicity analysis. It is controversial whether there is a time-window in which the apoptotic process generates comets that would falsely be interpreted to be the result of genotoxic DNA damage. Therefore, we evaluated frequency histograms for single-cell measures of tail DNA (% DNA in comet tail) in 30-min intervals after incubation of mouse lymphoma L5178Y cells with sodium arsenite (NaAsO2). In parallel, we evaluated apoptosis by measuring annexin V-positive cells with flow cytometry, and visualized apoptotic cells on slides by Hoechst bisbenzimide 33258 staining. The first observed effect at 30 min after treatment was an increase in annexin V-positive cells. At about 60 min the number of cells with moderate DNA migration increased in the comet-assay analysis. After 90 min, an increase in the number of cells with high levels of DNA migration was observed, which resulted in a bimodal distribution of cells with moderate and high levels of DNA migration. Hoechst-stained apoptotic cells could only be observed at later times (> or = 120 min). This means that the treatment would have been considered to be genotoxic if analysed at 120 min even if the cells with high levels of DNA migration would have been excluded. The occurrence of annexin V-positive cells preceded the appearance of cells with moderate levels of DNA migration. We hypothesize that these cells were early apoptotic cells and not indicative of genotoxic damage. We conclude that DNA-damaging effects of NaAsO2 cannot adequately be interpreted if the comet assay is not accompanied by separate analysis of early endpoints for induction of apoptosis.