In Vitro Evaluation of Curcumin- and Quercetin-Loaded Nanoemulsions for Intranasal Administration: Effect of Surface Charge and Viscosity

The nose-to-brain delivery of neuroprotective natural compounds is an appealing approach for the treatment of neurodegenerative diseases. Nanoemulsions containing curcumin (CUR) and quercetin (QU) were prepared by high-pressure homogenization and characterized physicochemically and structurally. A negative (CQ_NE−), a positive (CQ_NE+), and a gel (CQ_NEgel) formulation were developed. The mean particle size of the CQ_NE− and CQ_NE+ was below 120 nm, while this increased to 240 nm for the CQ_NEgel. The formulations showed high encapsulation efficiency and protected the CUR/QU from biological/chemical degradation. Electron paramagnetic resonance spectroscopy showed that the CUR/QU were located at the interface of the oil phase in the proximity of the surfactant layer. The cytotoxicity studies showed that the formulations containing CUR/QU protected human nasal cells from the toxicity evidenced for blank NEs. No permeation across an in vitro model nasal epithelium was evidenced for CUR/QU, probably due to their poor water-solubility and instability in physiological buffers. However, the nasal cells’ drug uptake showed that the total amount of CUR/QU in the cells was related to the NE characteristics (CQ_NE− > CQ_NE+ > CQ_NEgel). The method used allowed the obtainment of nanocarriers of an appropriate size for nasal administration. The treatment of the cells showed the protection of cellular viability, holding promise as an anti-inflammatory treatment able to prevent neurodegenerative diseases.

Stochastic Assessment of Groundwater Contamination Risks From Onshore Gas Development Using Computationally Efficient Analytical and Numerical Transport Models

Regulators require the gas industry to assess the risks of unintentional release of chemicals to the environment and implement measures to mitigate it. Industry standard models for contaminant transport in aquifers do not explicitly model processes in the unsaturated zone and groundwater models often require long run times to complete simulation of complex processes. We propose a stochastic numerical-analytical hybrid model to overcome these two shortcomings and demonstrate its application to assess the risks associated with onshore gas drilling in the Otway Basin, South Australia. The novel approach couples HYDRUS-1D to an analytical solution to model contaminant transport in the aquifer. Groundwater velocities and chemical trajectories were derived from a particle tracking analysis. The most influential parameters controlling solute delivery to the aquifer were the soil chemical degradation constant and the hydraulic conductivity of a throttle soil horizon. Only 18% of the flow paths intercepted environmental receptors within a 1-km radius from the source, 87% of which had concentrations of <1% of the source. The proposed methodology assesses the risk to environmental assets and informs regulators to implement measures that mitigate risk down to an acceptable level.

Insights Into the Known 13C Depletion of Methane—Contribution of the Kinetic Isotope Effects on the Serine Hydroxymethyltransferase Reaction

We determined the kinetic isotope effect on the serine hydroxymethyltransferase reaction (SHMT), which provides important C1 metabolites that are essential for the biosynthesis of DNA bases, O-methyl groups of lignin and methane. An isotope effect on the SHMT reaction was suggested being responsible for the well-known isotopic depletion of methane. Using the cytosolic SHMT from pig liver, we measured the natural carbon isotope ratios of both atoms involved in the bond splitting by chemical degradation of the remaining serine before and after partial turnover. The kinetic isotope effect 13(VMax/Km) was 0.994 0.006 and 0.995 0.007 on position C-3 and C-2, respectively. The results indicated that the SHMT reaction does not contribute to the 13C depletion observed for methyl groups in natural products and methane. However, from the isotopic pattern of caffeine, isotope effects on the methionine synthetase reaction and on reactions forming Grignard compounds, the involved formation and fission of metal organic bonds are likely responsible for the observed general depletion of “activated” methyl groups. As metal organic bond formations in methyl transferases are also rate limiting in the formation of methane, they may likely be the origin of the known 13C depletion in methane.

Applications of Nanoemulsions in Food Manufacturing

Nanoemulsions are increasingly used in the food industry for the encapsulation of lipophilic compounds such as nutraceuticals, flavors, vitamins, antioxidants, and colors. The advantages of nanoemulsion-based encapsulation include increased bioavailability, higher solubility, control release, protection from chemical degradation, and incorporation of different ingredients into food products. Food industries are interested in the preparation of natural polymer-based nanoemulsions to prepare clean label products. A variety of polymers such as soya lecithin, WPI, GA, and modified starches have been used to fabricate nanoemulsion-based delivery systems for nutraceuticals and micronutrients. Hence, nanoemulsion-fortified food products have received great attention due to consumer demand for safer and healthier food products. Additionally, nanoemulsions can be used for the texture modification of food products and encapsulation as well as delivery of antimicrobial agents. The main challenge for the preparation of nanoemulsions is the selection of appropriate ingredients.

A Review of Microplastics Risk Assessment in the Coastal Environment

Pollution from microplastics has recently become a prevalent threat to the ecosystem. Microplastics with a dimension less than or equal to 5 mm are smaller. There are many ways that microplastics can reach the atmosphere. By various mechanisms, the breakdown of macro plastics will happen. Chemical degradation, tire abrasion, is the most common forms of degradation. Microplastics (MPs) pollution in the coastal and marine ecosystem is currently a global problem. Transferring MPs from land to sea and allowing them to enter the food chain has a direct negative impact on marine life and human health. The combined toxicity effects of MicroPlastics (MPs) and other contaminants in marine environments, as well as their toxicity effects and mechanisms based on a variety of environmentally important test organisms, were also covered in this study.

Solid Dosage Forms of Biopharmaceuticals in Drug Delivery Systems Using Sustainable Strategies

Drug delivery systems (DDS) often comprise biopharmaceuticals in aqueous form, making them susceptible to physical and chemical degradation, and therefore requiring low temperature storage in cold supply and distribution chains. Freeze-drying, spray-drying, and spray-freeze-drying are some of the techniques used to convert biopharmaceuticals-loaded DDS from aqueous to solid dosage forms. However, the risk exists that shear and heat stress during processing may provoke DDS damage and efficacy loss. Supercritical fluids (SCF), specifically, supercritical carbon dioxide (scCO2), is a sustainable alternative to common techniques. Due to its moderately critical and tunable properties and thermodynamic behavior, scCO2 has aroused scientific and industrial interest. Therefore, this article reviews scCO2-based techniques used over the year in the production of solid biopharmaceutical dosage forms. Looking particularly at the use of scCO2 in each of its potential roles—as a solvent, co-solvent, anti-solvent, or co-solute. It ends with a comparison between the compound’s stability using supercritical CO2-assisted atomization/spray-drying and conventional drying.

Blatter Radicals as Bipolar Materials for Symmetric Redox-Flow Batteries

Redox-active organic molecules are promising charge-storage materials for redox-flow batteries (RFBs), but material crossover between posolyte/negolyte and chemical degradation are limiting factors in the performance of all-organic RFBs. We demonstrate that the bipolar electrochemistry of 1,2,4-benzotriazin-4-yl (Blatter) radicals allows construction of batteries with symmetric electrolyte composition. Cyclic voltammetry shows that these radicals retain reversible bipolar electrochemistry also in the presence of water. The redox potentials of derivatives with a C(3)-CF3 substituent are least affected by water and, moreover, these compounds show >90% capacity retention after charge/discharge cycling in a static H-cell for seven days (ca. 100 cycles). Testing these materials in a flow regime at 0.1 M concentration of active material confirmed the high cycling stability under conditions relevant for RFB operation, and demonstrated that polarity inversion in a symmetric flow battery may be used to rebalance the cell. Chemical synthesis provides insight in the nature of the charged species by spectroscopy and (for the oxidized state) X-ray crystallography. The stability of these compounds in all three states of charge highlights the potential for application in symmetric organic redox-flow batteries.

Marine Health-Promoting Compounds: Recent Trends for Their Characterization and Human Applications

Seaweeds represent a rich source of biologically active compounds with several applications, especially in the food, cosmetics, and medical fields. The beneficial effects of marine compounds on health have been increasingly explored, making them an excellent choice for the design of functional foods. When studying marine compounds, several aspects must be considered: extraction, identification and quantification methods, purification steps, and processes to increase their stability. Advanced green techniques have been used to extract these valuable compounds, and chromatographic methods have been developed to identify and quantify them. However, apart from the beneficial effects of seaweeds for human health, these natural sources of bioactive compounds can also accumulate undesirable toxic elements with potential health risks. Applying purification techniques of extracts from seaweeds may mitigate the amount of excessive toxic components, ensuring healthy and safer products for commercialization. Furthermore, limitations such as stability and bioavailability problems, chemical degradation reactions during storage, and sensitivity to oxidation and photo-oxidation, need to be overcome using, for example, nanoencapsulation techniques. Here we summarize recent advances in all steps of marine products identification and purification and highlight selected human applications, including food and feed applications, cosmetic, human health, and fertilizers, among others.

Novel peptide natural products from the NZ thermophilic microorganism Thermogemmatispora strain T81

<p><b>Genome mining of the newly described Thermogemmatispora strain T81, a thermophile from the Taupo Volcanic Zone, NZ, revealed the potential to produce novel ribosomally synthesised and post-translationally modified peptide natural products. Previous work established that strain T81 exhibits antimicrobial activity against a wide range of extremophilic bacteria. This thesis describes the mass spectrometry-guided screening of strain T81, and the subsequent isolation and structure elucidation of a novel lanthipeptide, tikitericin (32).</b></p> <p>Tikitericin is a class II lanthipeptide which bears no sequence homology to known lanthipeptides. Comprised of 35 amino acids, the three-dimensional structure of tikitericin is conformationally restricted by four macrocyclic structures formed by the non-proteinogenic residues methyllanthionine and lanthionine. The amino acid sequence, predicted through bioinformatic analysis, was confirmed by chemical degradation experiments and subsequent tandem mass spectrometry. Characterisation of tikitericin’s ring topology was performed by tandem mass spectrometry and stereochemical configuration of the (methyl)lanthionine residues was determined by gas chromatography mass spectrometry.</p>