Production of anti-inflammatory films based on cashew gum polysaccharide and polyvinyl alcohol for wound dressing applications

In the present study, we aimed to produce CGP/PVA films containing entrapped anti-inflammatory drugs for wound dressing applications. Using a 33-1 fractional factorial design, the effect of each component was evaluated on the physicochemical and morphological properties of the produced materials. The best formulation for entrapment of diclofenac sodium and ketoprofen was also determined. The produced films presented high swelling capacity, with some formulations showing o porous structure. CGP/PVA films showed a maximum retention of 75.6% for diclofenac sodium and 32.2% for ketoprofen, and both drugs were released in a controlled manner for up to 7 h. The drug release kinetic was studied, and the data were fitted using a Korsmeyer-Peppas model, which suggested that the release mechanism is controlled by diffusion. These results indicate that CGP/PVA-based matrices have great potential to be used as drug-delivery systems for wound dressing applications, contributing to prolonging the drug's action time and then improving their anti-inflammatory efficacy.

Development of a Halochromic, Antimicrobial, and Antioxidant Starch-Based Film Containing Phenolic Extract from Jaboticaba Peel

In this study, the antioxidant, antimicrobial, mechanical, optical, and barrier attributes of Solanum lycocarpum starch bio-based edible films incorporated with a phenolic extract from jaboticaba peel were investigated. Aiming to determine the effect of the polymers and the phenolic extract on the properties of the films, a three-factor simplex-lattice design was employed, and the formulation optimization was based on the produced films' antioxidant potential. The optimized formulation of the starch-PEJP film showed a reddish-pink color with no cracks or bubbles and 91% antioxidant activity against DPPH radical. The optimized starch-PEJP film showed good transparency properties and a potent UV-blocking action, presenting color variation as a function of the pH values. The optimized film was also considerably resistant and highly flexible, showing a water vapor permeability of 3.28 × 10-6 g m-1 h-1 Pa-1. The microbial permeation test and antimicrobial evaluation demonstrated that the optimized starch-PEJP film avoided microbial contamination and was potent in reducing the growth of Escherichia coli, Staphylococcus aureus, and Salmonella spp. In summary, the active starch-PEJP film showed great potential as an environmentally friendly and halochromic material, presenting antioxidant and antimicrobial properties and high UV-protecting activity.

Antioxidant and emulsifying properties of a galactose-rich heteropolysaccharide from Plinia cauliflora peels

In this study functional properties of a galactose-rich heteropolysaccharide (GH) were accessed. The bands of a galactose-rich polysaccharide were found in FTIR spectra, including those from the fingerprint region. GH was characterized as a dark-red material (L* 25.86 ± 0.75, a* 9.46 ± 1.01, b* 0.65 ± 0.14, Chroma 9.48 ± 1.02) with antioxidant activity of 21.5 ± 0.08, 12.1 ± 0.06 and 0.46 ± 0.04 mmol Trolox Eq mg^-1 GH in FRAP, DPPH and ABTS, respectively. GH presented 44.9% of esterification degree and 10.73 ± 0. 01 mg of GAE g^-1. The production parameters of GH emulsions (GH concentration, time and ultrasound power) were optimized using a 2³ Central Composite Rotatable Design (CCRD). Emulsion droplets presented particle size (d µm) varying from 0.823 ± 0.065 to 1.926 ± 0.151, polydispersity index (PDI) from 0.10 ± 0.05 to 0.40 ± 0.01 and zeta potential from -29.25 ± 3.98 to -33.75 ± 1.77. Finally, the high emulsifying activity (EA) (96.67%) and emulsion stability (ES) (97.44%) allow suggesting that GH is a promising polysaccharide for food applications.

An overview on the current available treatment for COVID-19 and the impact of antibiotic administration during the pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused several problems in healthcare systems around the world, as to date, there is no effective and specific treatment against all forms of COVID-19. Currently, drugs with therapeutic potential are being tested, including antiviral, anti-inflammatory, anti-malarial, immunotherapy, and antibiotics. Although antibiotics have no direct effect on viral infections, they are often used against secondary bacterial infections, or even as empiric treatment to reduce viral load, infection, and replication of coronaviruses. However, there are many concerns about this therapeutic approach as it may accelerate and/or increase the long-term rates of antimicrobial resistance (AMR). We focused this overview on exploring candidate drugs for COVID-19 therapy, including antibiotics, considering the lack of specific treatment and that it is unclear whether the widespread use of antibiotics in the treatment of COVID-19 has implications for the emergence and transmission of multidrug-resistant bacteria.

Recovery of rare earth elements from acid mine drainage by ion exchange

The current work addresses the study of the recovery of rare earth elements (REE) from acid mine water by using cationic exchange resin. The acid water was obtained from a closed uranium mine in Brazil. Ion exchange experiments were carried out in batch with three different resins at 25 ± 0.5°C and pH values 1.4, 2.4 and 3.4 (natural). Data were adjusted to the Langmuir equation in order to calculate the maximum loading capacity (q_max) of the resins. The results of q_max for individual REE revealed that the resins present higher loading for La in detriment to the other REE. The Dowex 50WX8 and Lewatit MDS 200 H resins demonstrated favourable sorption profiles to REE, evidenced by values of equilibrium factor (R_L) and higher values of the Langmuir constants (b). The separation factors (αHREELREE) indicates that resins are more selective for light REE at all pH studied. The selectivity of the resins for the REE can be described as light REE > heavy REE. The pH 1.4 and 3.4 are more favourable for the recovery of REE.

Oxidonitrergic and antioxidant effects of a low molecular weight peptide fraction from hardened bean (Phaseolus vulgaris) on endothelium

About 3000 tons of beans are not used in human food due to hardening. Several studies on bean-derived bioactive peptides have shown potential to treat some diseases, including those relying on oxidative dysfunctions. We assessed the effects of peptides extracted from hardened bean Phaseolus vulgaris (PV) on reactive oxygen species (ROS) and nitric oxide (NO) production, cytotoxic and cytoprotective effects in endothelial cells, and oxidonitrergic-dependent vasodilating effects. Extract was composed by peptide fraction <3 kDa (PV3) from hardened common bean residue. PV3 sequences were obtained and analyzed with bioinformatics. Human umbilical vein endothelial cells were treated with 10, 20, 30, and 250 µg/mL PV3. Oxidative stress was provoked by 3% H₂O₂. Cytotoxicity and cytoprotective effects were evaluated by MTT assay, whereas, ROS and NO were quantified using DHE and DAF-FM fluorescent probes by confocal microscopy. NO- and endothelium-dependent vasodilating effects of PV3 were assessed in isolated aortic rings. We found 35 peptides with an average mass of 1.14 kDa. There were no cell deaths with 10 and 20 μg/mL PV3. PV3 at 30 μg/mL increased cell viability, while cytotoxicity was observed only with 250 μg/mL PV3. PV3 at 10 μg/mL was able to protect cells from oxidative stress. PV3 also increased NO release without causing cell death. It also reduced relative ROS production induced by H₂O₂. PV3 vasodilating effects relied on endothelium-dependent NO release. PV3 obtained from low-commercial-value bean displays little cytotoxicity and exerts antioxidant effects, whereas it increases endothelial NO release.

A galactose-rich heteropolysaccharide extracted from "jaboticaba" (Plinia cauliflora) peels

The objective of this work was to extract, identify and characterize a galactose-rich heteropolysaccharide (GH) from "jaboticaba" peel. The best conditions to extract the GH according to a 2³ full-factorial experimental design were 90 °C/30 min/pH 1.0, resulting in a 32.32 % yield using lyophilized sample. The chemical structure analyzed by GC/MS and NMR spectra (HSQC/HSQC-TOCSY) showed that the main chain of GH consists of a (1→4) galactoside branched at carbon 3, containing galactose (67.21 %), glucose (15.78 %), arabinose (9.78 %), rhamnose (2.26 %) and traces of esterified and non-esterified uronic acids. Rheological studies revealed that GH suspensions behave as a Newtonian fluid, with calculated molecular mass of 1.48 × 10⁵ Da. The absolute viscosity of 1 % (w/v) aqueous suspension of GH decreased from 25 mPa s to 10 mPa s in NaCl and 7 mPa s in CaCl₂, indicating the polyelectrolyte character of GH.

Morphological and physicochemical characterization of starches from underground stems of Trimezia juncifolia collected in different phenological stages

In this study, starches from underground stems of Trimezia juncifolia were evaluated during dry season (DSS), wet season (WSS) and sprouting (SS). Results evidenced that drought stress did not interfere with the yield, amylose content and degree of polymerization (DP) of amylopectin. However, the extraction yield in SS was 58% lower, being observed and increase of 7.5% in the content of amylose, and 13.5% in DP values for SS amylopectin, with a predominance of A-chains. The amount of total sugar, the starch granules size as well as solubility and swelling properties varied as function of the phenological status. Also, starch granules changed from A-type polymorph in DSS and SS to a C_A-type in WSS. Nevertheless, it was observed a crystallinity reduction from 56% in DSS to 37.1% in SS. In addition, thermograms evidenced the presence of amylose-lipid complexes, with endothermic transition temperatures being affected by drought stress and sprouting. Finally, results demonstrate that underground stems from T. juncifolia have adaptative strategies involving changes in the morphological and physicochemical properties of the starch granules.

Antihyperglycemic and hypoglycemic activity of naturally occurring peptides and protein hydrolysates from easy-to-cook and hard-to-cook beans (Phaseolus vulgaris L.)

The present study was undertaken to examine the antidiabetic potential of naturally occurring peptides and hydrolysate fractions from easy-to-cook (ETC) and hard-to-cook (HTC) beans. All fractions were tested regarding their in vitro inhibitory activities against α-amylase and α-glucosidase as well as in vivo anti-hyperglycemic and hypoglycemic effects. Results evidenced that the peptide fractions with the lowest molecular weight (<3 kDa) have the highest inhibitory activities, and a 16.9%-89.1% inhibition of α-amylase and 34.4%-89.2% inhibition of α-glucosidase were observed. Regarding the antihyperglycemic activity, the fraction ETCNO3-10 showed a better performance than the positive control (acarbose). In addition, results from hypoglycemic activity evidenced that the tested peptide fractions were able to decrease the glucose levels at the same extension of glibenclamide, maintaining a constant basal glucose level without a postprandial hyperglycemia peak. Finally, it is possible to suggest that the naturally occurring peptides and hydrolysate fractions obtained from ETC and HTC common beans could be used in functional food production or pharmaceutical formulations to prevent diabetes.

Development and optimization of a new culture media using extruded bean as nitrogen source

The composition of a culture medium is one of the most important parameters to be analyzed in biotechnological processes with industrial purposes, because around 30–40% of the production costs were estimated to be accounted for the cost of the growth medium [1]. Since medium optimization using a one-factor-at-a-time approach is time-consuming, expensive, and often leads to misinterpretation of results, statistical experimental design has been applied to medium optimization for growth and metabolite production [2], [3], [4], [5]. In this scenario, the use of mixture design to develop a culture medium containing a cheaper nitrogen source seems to be more appropriate and simple. In this sense, the focus of this work is to present a detailed description of the steps involved in the development of a optimized culture medium containing extruded bean as nitrogen source.

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In a previous work we tested a development of new culture media based on the composition of YPD medium, aiming to reduce bioprocess costs as well as to improve the biomass production and heterologous expression.

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The developed medium was tested for growth of Saccharomyces cerevisiae and Pichia pastoris (GS 115).

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The use of culture media containing extruded bean as sole nitrogen source showed better biomass production and protein expression than those observed in the standard YPD medium.

A bioactive film based on cashew gum polysaccharide for wound dressing applications

This work presents the development of a new bioactive material for wound therapeutics which may play a dual role of modulate metallo proteinases activity while prevents infection blocking out pathogenic microorganisms and foreign materials. A CGP/PVA film was activated by covalent immobilization of trypsin. Results from biocompatibility test revealed that PDL fibroblasts grown on the surface of CGP/PVA and the high amount of viable cells proved absence of cytotoxicity. Trypsin immobilized onto CGP/PVA film remained 100% active after 28 days stored dried at room temperature. In addition, CGP/PVA-trypsin film could be used for 9 cycles of storage/use without loss of activity. After immobilization, trypsin retained its collagenolytic activity, indicating this material as a promising material for wound dressing applications.

Influence of Storage on Darkening and Hardening of Slow- and Regular-Darkening Carioca Bean (Phaseolus vulgaris L.) Genotypes

New carioca bean cultivars are being introduced into the market necessitating their evaluation under trade conditions, which often require storage under ambient conditions. We therefore evaluated the darkening and hardening processes of six carioca bean genotypes each representing regular and slow darkening trait during storage under ambient conditions for five months to elucidate their relationship as a breeding strategy. Storage time adversely affected color characteristics (L*, a*, b*, C* and ΔE) depending on bean genotype, whereas hardness and resistance to cooking increased during storage independent of the lignification process. Bean darkening and hardening occurred during storage at different intensities in each genotype and were not always correlated. BRSMG-Madrepérola, a slow darkening genotype, was unaffected (resistant to storage conditions), whereas BRS-Pontal with regular tegument darkening, was highly susceptible to storage conditions reflected in extended cooking time and darkening (low L* values). Principal component and cluster analyses on 8 constituents analyzed in this study demonstrate the difference in color characteristics, cooking time and hardness as major factors in segregating the bean genotypes. Seed coat color is an important but inappropriate single parameter for predicting the resistance to cooking or hardness induced by storage of carioca beans under ambient conditions. Development of carioca bean genotypes resistant to storage conditions is essential in reducing food losses during postharvest.

Potential fungal inhibition by immobilized hydrolytic enzymes from Trichoderma asperellum

The use of cell wall degrading enzymes from Trichoderma asperellum immobilized on biodegradable support is an alternative for food packaging. In this study, hydrolytic enzymes produced by T. asperellum were tested as a fungal growth inhibitor, in free form or immobilized on a biodegradable film composed of cassava starch and poly(butylene adipate-co-terephtalate) (PBAT). The inhibitory activity was tested against Aspergillus niger , Penicillium sp., and Sclerotinia sclerotiorum , microorganisms that frequently degrade food packaging. The use of chitin as carbon source in liquid medium induced T. asperellun to produce N-acetylglucosaminidase, β-1,3-glucanase, chitinase, and protease. The presence of T. asperellun cell wall degradating enzymes (T-CWD) immobilized by adsorption or covalent attachment resulted in effective inhibition of fungal growth. The enzymatic activity of T-CWD was stronger on S. sclerotiorum than on the Aspergillus or Penicillum isolates tested. These results suggest that T-CWD can be used in a free or immobilized form to suppress fungi that degrade food packaging.

Biodegradation of epoxyconazole and piraclostrobin fungicides by Klebsiella sp. from soil

Three bacterial strains have been isolated from soil in which soybean had been continuously cropped and treated with Opera(®), a fungicide containing epoxyconazole and pyraclostrobin. The three strains (1,805, 2,801 and 3,803), obtained from soil at 80-100 cm depth, were selected on medium containing 0.03% Opera(®). Morphological examination revealed that the strains were Gram-negative, and two of them (1,805 and 2,801) exhibited polymorphism. The growth profiles demonstrated that 1,805 and 3,803 were more efficient growing in the presence of Opera(®) than 2,801. Maximum growth was reached between 24 and 48 h, however, 2,801 was not able to survive after this period. The total protein content produced by 1,805, 2,801 and 3,803 in liquid selective medium containing Opera(®) were 111.0 ± 0.02, 80.0 ± 0.05 and 130.5 ± 0.07 μg/ml, respectively. According to its biochemical and molecular features, strain 1,805 was identified as Klebsiella sp. On the basis of the characteristics presented (facultative anaerobic nature, polymorphic character and capacity of growing in the presence of Opera(®)) strain 1,805 seems to be able to degrade the epoxyconazole and pyraclostrobin.