Chitosan nanoparticles production: optimization of physical parameters, biochemical characterization, and stability upon storage

Ionic gelation is among the simplest processes for the development of chitosan nanoparticles reported so far in the literature. Its one‑shot synthesis process in conjunction with the mild reaction conditions required are among the main causes for its success. In this work, we sought to optimize a set of physical parameters associated with the ionic gelation process at two different pH values. Following that, the NPs’ freeze‑drying and long‑term storage stability were assayed, and their biocompatibility with HaCat cells was evaluated. The results show that NPs were more homogenously produced at pH 5, and that at this pH value, it was possible to obtain a set of optimum production conditions. Furthermore, of the assayed parameters, TPP addition time and overall reaction time were the parameters which had a significant impact on the produced NPs. Nanoparticle freeze‑drying led to particle aggregation, and, of the cryoprotectants, assayed mannitol at 10% (w/v) presented the best performance, as the NPs were stable to freeze‑drying and maintained their size and charge in the long‑term stability assay. Lastly, the chitosan NPs presented no toxicity towards the HaCat cell line.info:eu-repo/semantics/publishedVersio

GC-FID as a complementary tool to understand fatty acids’ role in cellular antioxidant activity: a pathway towards understanding iROS production in cells exposed to essential oils for cosmeceutical applications

In the cosmeceutical industry, the development of various products relies heavily upon essential oils due to two crucial reasons: first the eco-sustainability drive that demands the application of natural products in all formulations and secondly their intrinsic aromatic characteristics and the beneficial biological properties normally apported to these compounds. However, they aren’t without drawbacks as they can induce various adverse reactions when in contact with the skin, namely dermal reactions and contact dermatitis, with most of these problems being associated with the essential oils’ oxidation. With that in mind, most compounds are tested for their Cellular Antioxidant Capacity (CAA) to ascertain if they are involved in the formation of intracellular Reactive Oxygen Species (iROS) in the cytoplasmatic environment of skin related cells. However, while the data generated from this assay may be crucial for the cosmeceutical industry, it lacks a basal understanding of the mechanism behind the result observed.info:eu-repo/semantics/publishedVersio

Genomic African and Native American Ancestry and Chagas Disease: The Bambui (Brazil) Epigen Cohort Study of Aging.

BackgroundThe influence of genetic ancestry on Trypanosoma cruzi infection and Chagas disease outcomes is unknown.Methodology/principal findingsWe used 370,539 Single Nucleotide Polymorphisms (SNPs) to examine the association between individual proportions of African, European and Native American genomic ancestry with T. cruzi infection and related outcomes in 1,341 participants (aged ≥ 60 years) of the Bambui (Brazil) population-based cohort study of aging. Potential confounding variables included sociodemographic characteristics and an array of health measures. The prevalence of T. cruzi infection was 37.5% and 56.3% of those infected had a major ECG abnormality. Baseline T. cruzi infection was correlated with higher levels of African and Native American ancestry, which in turn were strongly associated with poor socioeconomic circumstances. Cardiomyopathy in infected persons was not significantly associated with African or Native American ancestry levels. Infected persons with a major ECG abnormality were at increased risk of 15-year mortality relative to their counterparts with no such abnormalities (adjusted hazard ratio = 1.80; 95% 1.41, 2.32). African and Native American ancestry levels had no significant effect modifying this association.Conclusions/significanceOur findings indicate that African and Native American ancestry have no influence on the presence of major ECG abnormalities and had no influence on the ability of an ECG abnormality to predict mortality in older people infected with T. cruzi. In contrast, our results revealed a strong and independent association between prevalent T. cruzi infection and higher levels of African and Native American ancestry. Whether this association is a consequence of genetic background or differential exposure to infection remains to be determined

Impact assessment of interregional government transfers in Brazil: an input-output approach

Redistributive policies carried out by the central government through interregional government transfers is a relevant feature of the Brazilian federal fiscal system. Regional shares of the central government revenues in the poorer regions have been recurrently smaller than the shares of central government expenditures in those regions. Appeal to core-periphery outcomes could be made, as São Paulo, the wealthiest state in the country, concentrated, in 2005, over 40% of total Federal tax revenue, receiving less than 35% of Federal expenditures. These figures suggest a redistribution of public funds from the spatial economic core of the economy to the peripheral areas. This paper investigates the role interregional transfers play in the redistribution of activities in the country, using an interregional input-output approach. Counterfactual simulations allow us to estimate some costs and benefits, for the core and periphery respectively, from such fiscal mechanisms.Interregional government transfers, input-output analysis, impact analysis, Brazilian economy

Insights into the biocompatibility and biological potential of a chitosan nanoencapsulated textile dye

Traditionally synthetic textile dyes are hazardous and toxic compounds devoid of any biological activity. As nanoencapsulation of yellow everzol textile dye with chitosan has been shown to produce biocompatible nanoparticles which were still capable of dyeing textiles, this work aims to further characterize the biocompatibility of yellow everzol nanoparticles (NPs) and to ascertain if the produced nanoencapsulated dyes possess any biological activity against various skin pathogens in vitro assays and in a cell infection model. The results showed that the NPs had no deleterious effects on the HaCat cells’ metabolism and cell wall, contrary to the high toxicity of the dye. The biological activity evaluation showed that NPs had a significant antimicrobial activity, with low MICs (0.5–2 mg/mL) and MBCs (1–3 mg/mL) being registered. Additionally, NPs inhibited biofilm formation of all tested microorganisms (inhibitions between 30 and 87%) and biofilm quorum sensing. Lastly, the dye NPs were effective in managing MRSA infection of HaCat cells as they significantly reduced intracellular and extracellular bacterial counts.info:eu-repo/semantics/publishedVersio