Acute Phytotoxicity and Antifungal Effect of Nanochitosan Particles on Colletotrichum fructicola with Low Susceptibility to Chitosan.

Colletotrichum fungus complex affects several crops and tropical products, which suffer significant losses due to anthracnose. The use of chitosan nanoparticles (CNPs), alone or in combination with bioactive compounds, has been recommend for agronomic applications. However, there is very little information on their phytotoxicity, and there is no information about the effect on microorganisms with low susceptibility to chitosan.

Cellular Internalization and Toxicity of Chitosan Nanoparticles Loaded with Nobiletin in Eukaryotic Cell Models ( and ).

This study involved the synthesis and characterization of chitosan nanoparticles loaded with nobiletin (CNpN) and assessed their toxicity and cellular internalization in eukaryotic cell models ( and ). Nanoparticles were prepared via the nanoprecipitation method and physicochemically characterized to determine their hydrodynamic diameter using dynamic light scattering (DLS), their surface charge through ζ-potential measurements, and their chemical structure via Fourier-transform infrared spectroscopy (FTIR). The hydrodynamic diameter and ζ-potential of chitosan nanoparticles (CNp) and CNpN were found to be 288.

Synthesis and toxicological study of chitosan-pirul (Schinus molle L.) essential oil nanoparticles on Aspergillus flavus.

In recent years, the study of essential oils as antifungal alternatives and their encapsulation to increase their properties for greater effects has been tested. In this work, nanoparticles of chitosan-Schinus molle L. essential oil (CS-PEO-Np) with a size of 260 ± 31.

Effect of a Prolonged-Release System of Urea on Nitrogen Losses and Microbial Population Changes in Two Types of Agricultural Soil.

Urea is the nitrogen-containing fertilizer most used in agricultural fields; however, the nutrient given by the urea is lost into the environment. The aim of this research was to determine the effect of two soil textures by applying a prolonged-release system of urea (PRSU) on the N losses. This research shows an important decrease of the nitrate and ammonium losses from 24.

Nanoparticles of Betalain-Gelatin with Antioxidant Properties by Coaxial Electrospraying: Preparation and Characterization.

Betalains are bioactive compounds with attractive antioxidant properties for the food industry, endowing them with potential application in food coatings to maintain quality and extend shelf life. However, they have low stability to factors such as light, temperature, and humidity. An alternative to protect bioactive compounds is nanoencapsulation; one of the most used techniques to produce an encapsulation is coaxial electrospraying.

Tetrandrine Derivatives as Promising Antibacterial Agents.

This work reports on the antibacterial activity of two tetrandrine derivatives, with acridine () and anthracene () units, against Gram-positive and Gram-negative bacteria of clinical importance by the broth microdilution method as well as their antioxidant activity against ABTS and DPPH radicals. Unlike natural tetrandrine, its derivatives inhibited bacterial growth, showing selectivity against with notable activity of (MIC = 0.035 μg/mL); this compound also has good activity against the ABTS radical (IC = 4.

Properties of Cephalopod Skin Ommochromes to Inhibit Free Radicals, and the Maillard Reaction and Retino-Protective Mechanisms in Cellular Models Concerning Oxidative Stress, Angiogenesis, and Inflammation.

Ommochromes are pigments of invertebrates that exhibit oxidative stress protection. The aim of this study was to investigate ommochromes extracted from cephalopod's skin for their ability to inhibit age-related-macular degeneration (AMD)-related factors such as HO-induced and iron-dependent oxidative stress (ferroptosis and erastin), accumulation of advanced glycation end-products (AGEs), as well as vascular endothelial growth factor (VEGF), and inflammatory cytokines (interleukin 6 and interleukin 8) secretion. As cell systems, we used primary porcine retinal pigment epithelium (RPE), human retinal pigment epithelium cell line ARPE-19 and uveal melanoma cell line OMM-1.

Inhibition of Pathogenic Bacteria and Fungi by Natural Phenoxazinone from Octopus Ommochrome Pigments.

Cephalopods, in particular octopus (), have the ability to alter their appearance or body pattern by showing a wide range of camouflage by virtue of their chromatophores, which contain nanostructured granules of ommochrome pigments. Recently, the antioxidant and antimicrobial activities of ommochromes have become of great interest; therefore, in this study, the pH-dependent redox effect of the extraction solvent on the antioxidant potential and the structural characterization of the pigments were evaluated. Cell viability was determined by the microdilution method in broth by turbidity, MTT, resazurin, as well as fluorescence microscopy kit assays.

Relationship between the Antifungal Activity of Chitosan-Capsaicin Nanoparticles and the Oxidative Stress Response on .

The fungus Aspergillus parasiticus is a contaminant in agricultural crops and its eradication involves the indiscriminate use of harmful synthetic pesticides. In the search for antifungal agents of natural origin, chitosan (Q) and capsaicin (C) are coupled in the form of nanoparticles (Np), which can possess a direct application under specific conditions. Due to their small size, Np can cross through the cell wall, taking the cells into a pro-oxidant environment known as “oxidative stress”, which presents when the reactive oxygen species (ROS) surpass the number of antioxidants in the cell.

Nutraceuticals/Drugs Promoting Mitophagy and Mitochondrial Biogenesis May Combat the Mitochondrial Dysfunction Driving Progression of Dry Age-Related Macular Degeneration.

In patients with age-related macular degeneration (AMD), the crucial retinal pigment epithelial (RPE) cells are characterized by mitochondria that are structurally and functionally defective. Moreover, deficient expression of the mRNA-editing enzyme Dicer is noted specifically in these cells. This Dicer deficit up-regulates expression of Alu RNA, which in turn damages mitochondria-inducing the loss of membrane potential, boosting oxidant generation, and causing mitochondrial DNA to translocate to the cytoplasmic region.

Au@Ag Core@Shell Nanoparticles Synthesized with Rumex hymenosepalus as Antimicrobial Agent.

In this work, we used a sequential method of synthesis for gold-silver bimetallic nanoparticles with core@shell structure (Au@AgNPs). Rumex hymenosepalus root extract (Rh), which presents high content in catechins and stilbenes, was used as reductor agent in nanoparticles synthesis. Size distribution obtained by Transmission Electron Microscopy (TEM) gives a mean diameter of 36 ± 11 nm for Au@AgNPs, 24 ± 4 nm for gold nanoparticles (AuNPs), and 13 ± 3 nm for silver nanoparticles (AgNPs).

Synthesis and Characterization of a FeO@PNIPAM-Chitosan Nanocomposite and Its Potential Application in Vincristine Delivery.

In this research, we conducted a systematic evaluation of the synthesis parameters of a multi-responsive core-shell nanocomposite (FeO nanoparticles coated by poly(N-isopropylacrylamide) (PNIPAM) in the presence of chitosan (CS) (FeO@PNIPAM-CS). Scanning electron microscopy (SEM) was used to follow the size and morphology of the nanocomposite. The functionalization and the coating of FeO nanoparticles (Nps) were evaluated by the ζ-potential evolution and Fourier Transform infrared spectroscopy (FTIR).

Characterization of Epigallocatechin-Gallate-Grafted Chitosan Nanoparticles and Evaluation of Their Antibacterial and Antioxidant Potential.

Nanoparticles based on chitosan modified with epigallocatechin gallate (EGCG) were synthetized by nanoprecipitation (EGCG-g-chitosan-P). Chitosan was modified by free-radical-induced grafting, which was verified by Fourier transform infrared (FTIR). Furthermore, the morphology, particle size, polydispersity index, and zeta potential of the nanoparticles were investigated.

Persistence of the antifungal capacity of a fraction of plant against after continuous exposure.

This study aimed to determine the ability of in developing mechanisms to counteract the antifungal effect of a fraction from plant extract (JmAF), as well as the morphological and physiological changes that occur during its exposure. The fungus was exposed to JmAF during consecutive periods. A culture sample was taken weekly to determine radial growth, spore germination and size, and fungal β-1,3-glucanase activity.

Phytotoxicity, cytotoxicity, and in vivo antifungal efficacy of chitosan nanobiocomposites on prokaryotic and eukaryotic cells.

Chitosan (CS) nanosystems have potential applications for the control of microorganisms in the medical, environmental, and agrifood fields. In vivo and in vitro assays of CS nanosystems have experienced increased activity due to improved physicochemical properties, biological activity, and reactivity. Hence, it is important to determine whether their application involves toxicological risks.

Proteomic analysis of the inhibitory effect of the butanolic fraction of on .

, a plant native to northwestern Mexico, has an inhibitory effect against phytopathogenic fungi. Previous studies have shown that the butanolic extract of causes retardation and atrophy in mycelial growth of . However, the action mechanism of this extract is unknown.

Biosorption of copper by immobilized biomass of Aspergillus australensis. Effect of metal on the viability, cellular components, polyhydroxyalkanoates production, and oxidative stress.

Heavy metals are toxic especially when they are introduced into the environment due to anthropogenic activities such as metallurgy, mining, and tanning. Removing these pollutants has become a worldwide concern since they cannot be degraded into nontoxic forms causing extended effects in the ecosystems. The use of an Aspergillus australensis was evaluated in order to remove Cu from simulated wastewater.

Inhibition of the antioxidant activity of catalase and superoxide dismutase from exposed to a antifungal fraction.

The aim of this study was to investigate the effect of an antifungal fraction obtained from plant (JmAF) in the generation of reactive oxygen species (ROS) and the activity of the catalase (CAT) and superoxide dismutase (SOD) enzymes from , as well as their influence in the viability of the fungus spores. The compounds present in the JmAF were determined by gas chromatography/quadrupole time-of-flight mass spectrometry (GC/QTOF-MS). The effect of the exposition to JmAF on the generation of ROS, as well as in the CAT and SOD activities in , was determined.

Toxicological Assessment of Cross-Linked Beads of Chitosan-Alginate and Biomass, with Efficiency as Biosorbent for Copper Removal.

Sorbent materials of biological origin are considered as an alternative to the use of traditional methods in order to remove heavy metals. Interest in using these materials has increased over the past years due to their low cost and friendliness to the environment. The objective of this study was to synthesize and characterize cross-linked beads made of chitosan, alginate, and mycelium of a copper-tolerant strain of .

Synthesis of chitosan biocomposites loaded with pyrrole-2-carboxylic acid and assessment of their antifungal activity against Aspergillus niger.

A wide variety of chitosan (CS) biomaterials have been loaded with different antimicrobial agents to improve the activity of CS against phytopathogenic fungi. Recently, the antimicrobial activity of 1H-pyrrole-2-carboxylic acid (PCA) has been reported as a secondary metabolite of Streptomyces griseus, which was identified as the main bioactive compound in the biological control. However, it is sensitive to light and its activity against filamentous fungi has not yet been reported.

Effect of pepper tree () essential oil-loaded chitosan bio-nanocomposites on postharvest control of and quality evaluations in avocado () cv. Hass.

Preventive and curative activity of postharvest treatments with chitosan nanoparticles (CS) and chitosan biocomposites loaded with pepper tree essential oil (CS-PEO) against anthracnose were evaluated on Avocado () cv. Hass artificially inoculated in rind wounds. After 10 days of storage significant preventive and curative activity against was observed with the absence of internal damage by applying CS and CS-PEO.

Activity of chitosan-lysozyme nanoparticles on the growth, membrane integrity, and β-1,3-glucanase production by .

Synthesis of nanocomposites from antimicrobial biopolymers such as chitosan (CS) and lysozyme (LZ) is an important and promising area in bionanotechnology. Chitosan-lysozyme (CS-LZ) nanoparticles (NPs) were prepared by the nanoprecipitation method, using commercial chitosan of 153 kDa. TEM and dynamic light scattering (DLS) analysis were carried out to evaluate the morphology, size, dispersion, and Z potential.

Preparation and Characterization of Extruded Composites Based on Polypropylene and Chitosan Compatibilized with Polypropylene-Graft-Maleic Anhydride.

The preparation of composites of synthetic and natural polymers represent an interesting option to combine properties; in this manner, polypropylene and chitosan extruded films using a different proportion of components and polypropylene-graft-maleic anhydride (PPgMA) as compatibilizer were prepared. The effect of the content of the biopolymer in the polypropylene (PP) matrix, the addition of compatibilizer, and the particle size on the properties of the composites was analyzed using characterization by fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), tensile strength, and contact angle, finding that in general, the addition of the compatibilizer and reducing the particle size of the chitosan, favored the physicochemical and morphological properties of the films.

Functionalization of chitosan by a free radical reaction: Characterization, antioxidant and antibacterial potential.

Chitosan was functionalized with epigallocatechin gallate (EGCG) by a free radical-induced grafting procedure, which was carried out by a redox pair (ascorbic acid/hydrogen peroxide) as the radical initiator. The successful preparation of EGCG grafted-chitosan was verified by spectroscopic (UV, FTIR and XPS) and thermal (DSC and TGA) analyses. The degree of grafting of phenolic compounds onto the chitosan was determined by the Folin-Ciocalteu procedure.

Potentiation of antifungal effect of a mixture of two antifungal fractions obtained from Baccharis glutinosa and Jacquinia macrocarpa plants.

The aim of the present work was to evaluate the effect of mixtures of antifungal fractions extracted from Baccharis glutinosa and Jacquinia macrocarpa plants on the development of the filamentous fungi Aspergillus flavus and Fusarium verticillioides. The minimal inhibitory concentration that inhibited 50% of growth (MIC50) of each plant antifungal fraction was determined from the percentage radial growth inhibition of both fungi. Binomial mixtures made with both plant fractions were used at their MIC50 to determine the Fractional Inhibitory Concentration index (FIC index) for each fungus in order to evaluate their synergistic effect.