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Currently, cannabis is considered an attractive option for the treatment of various diseases, including pain management. Thus, developing new analgesics is paramount for improving the health of people suffering from chronic pain. Safer natural derivatives such as cannabidiol (CBD) have shown excellent potential for the treatment of these diseases. This study aimed to evaluate the analgesic effect of a CBD-rich cannabis extract (CE) encapsulated in polymeric micelles (CBD/PMs) using different pain models. The PEG-PCL polymers were characterized by gel permeation chromatography and 1 H-NMR spectroscopy. PMs were prepared by solvent evaporation and characterized by dynamic light scattering (DLS) and transmission electron microscopy. The analgesic activity of CBD/PMs and nonencapsulated CE rich in CBD (CE/CBD) was evaluated using mouse thermal, chemical, and mechanical pain models. The acute toxicity of the encapsulated CE was determined by oral administration in mice at a dose of 20 mg/kg for 14 days. The release of CBD from the nanoparticles was assessed in vitro using a dialysis experiment. CBD/PMs with an average hydrodynamic diameter of 63.8 nm obtained from a biocompatible polyethylene glycol-block-polycaprolactone copolymer were used as nanocarriers for the extract formulations with 9.2% CBD content, which corresponded with a high encapsulation efficiency of 99.9%. The results of the pharmacological assays indicated that orally administered CBD/PMs were safe and exerted a better analgesic effect than CE/CBD. The micelle formulation had a significant analgesic effect in a chemical pain model, reaching a percentage of analgesia of 42%. CE was successfully encapsulated in a nanocarrier, providing better stability. Moreover, it proved to be more efficient as a carrier for CBD release. The analgesic activity of CBD/PMs was higher than that of free CE, implying that encapsulation is an efficient strategy for improving stability and functionality. In conclusion, CBD/PMs could be promising therapeutics for pain management in the future.

The evaluation of the electrochemical determination of Saccharomyces cerevisiae was carried out using a screen-printed carbon electrode (SPCE) modified with Nafion-dispersed oxidized multi-walled carbon nanotubes (OMWCNT). The morphology was studied using scanning electron microscopy (SEM), showing a complete modification of the surface with the nanotubes and yeast interaction with them instead of the graphite surface. The redox couple Fe(CN) 6 4- was used to determine the electroactive area, the heterogeneous transfer constant, and the Nafion® effect. Results showed increases in electroactive area and heterogeneous transfer constant of 146% and 20.4%, respectively, due to the presence of nanotubes. Studies of the Nafion® effect showed that the polymeric membrane affects the electroactive area but not the heterogeneous transfer constant. Studies of the scan rate effect show that yeast oxidation is an irreversible mixed control process. As the concentration and scan rate increased, the anodic potential shifted toward more anodic values. The relationship between yeast concentration and the anodic current density (current/electroactive area) of yeast showed a linear range between 0.61 and 7.69 g L 6 , the limit of detection (LOD) and the limit of quantification (LOQ) were 0.17 g L 3- , and 0.61 g L -1 , respectively, and the sensibility obtained was 0.03 μA L g -1 , and 0.61 g L -1 , respectively, and the sensibility obtained was 0.03 μA L g -1  mm -2 . These results show that with the screen-printed carbon electrodes it is possible to improve the electrochemical determination of this microorganism, enhancing the analytical parameters and quantification, allowing greater portability and decreasing measurement times and associated waste., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

The electrochemical behavior of Saccharomyces cerevisiae sp was studied using a glassy carbon electrode (GCE) modified with Nafion-dispersed oxidized multi-walled carbon nanotubes (OMWCNT). The morphology was studied using scanning electron microscopy (SEM), showing that the yeast sticks to the carbon nanotube surface instead of the glassy carbon surface. The redox couple Fe(CN) 6 4- was used to determine the electroactive area and the heterogeneous transfer constant, which increased 80.5% and 108% respectively by the presence of nanotubes. The studies of the pH effect showed that the anodic potential decreases at alkaline pH and that the highest current intensity occurs at a pH value of 7.00. Studies of the scan rate effect have shown that yeast oxidation is an irreversible mixed control process in which two electrons participate. The relationship between yeast concentration and the anodic current density was studied using different electrochemical techniques obtaining the best analytical parameters through chronoamperometry. The linear range was between 3.36 and 6.52 g L 6 , the limit of detection (LOD) and the limit of quantification (LOQ) were 0.98 g L 3- and 3.36 g L -1 respectively, and the sensibility obtained was 0.086 μA L g -1 and 3.36 g L -1 respectively, and the sensibility obtained was 0.086 μA L g -1 mm -2 . These results show that the multi-walled carbon nanotubes in water and Nafion® allow obtaining an anodic signal corresponding to the yeast, which facilitates its quantification through electrochemical methodologies, favoring the reduction of analysis times and costs compared with other techniques., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors. Published by Elsevier B.V.)

In this work, for the first time, the direct usability of natural products, catechins (CT) and cocoa powder (CO), as electrochemical mediators able to modify a carbon black modified screen-printed electrode (SPE-CB) is proved, and, as proof of applicability, free (GSH) and total glutathione (GSH + GSSG) in blood samples is successfully determined. Noteworthy, the cocoa powder (naturally rich in catechins), dissolved in DMSO, was able to give rise to a useful highly redox-active catechol-quinone surface-confined system onto a carbon black nanoparticles modified screen-printed electrode (SPE-CB-CO - Cocoatrode), giving rise to a similar behaviour obtained with pure catechins (SPE-CB-CT). The electrodeposition process has been carefully studied, the resulting immobilized natural mediator (obtained using both CT and CO) features investigated, and the performance of the resulting sensors (SPE-CB-CT and Cocoatrode) tested and compared. Both modified electrodes (SPE-CB-CT and Cocoatrode) have a good inter-electrodes precision (RSD i p,a ≤ 4.2%, n = 3) and intra-electrodes repeatability (RSD i p,a ≤ 3.9%, n = 20), indicating a robust and stable 'fabrication' strategy. Finally, SPE-CB-CT and Cocoatrode have been employed for the detection of free (GSH) and total (GSH+GSSG) glutathione in blood samples, using differential pulse voltammetry decrease in the mediator's reduction peak (Δi %), as analytical signal. Analytical curves (R 2  ≥ 0.998), for the GSH detection, have been determined both with SPE-CB-CT and Cocoatrode in the 2.5 × 10 -8 -6.0 × 10 -5  M and 5.0 × 10 -8 -1.0 × 10 -4  M concentration ranges, respectively. Limits of detections (LODs) were ≤2.6 × 10 -8  M. GSH (free and total) determined in blood samples, by the proposed CT and CO sensors, showed a good intra-electrode repeatability (RSD i p,a ≤ 9.0%, n = 3), with good recoveries (from 88.3% to 117.7%). The values obtained were in agreement with a classical spectrophotometric method (GSH and GSSG concentration relative error between -4.7 and +9.8%). The SPE-CB-CT and the Cocoatrode platforms demonstrated high potentiality in sensing and biosensing scenario, opening new gates to the natural/food products employment as unconventional, eco-friendly and economically affordable analytical active tools., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The antioxidant capacity in mango (pulp, peel, and seed) was measured using spectrophotometric and electrochemical methods in order to make traditional methods comparable with electrochemical ones, using reference standards Gallic Acid and Trolox. ABTS, DPPH, Total polyphenols, and electrochemical index were evaluated. In order to present the electrochemical results in a more comparable way, the voltammetric charge (using Differential pulse voltammetry) was used. Spectrophotometric methods allowed to determine the difference in contents of metabolites with antioxidant capacity, except in peel and seed, while the electrochemical method separated the three extracts and is not affected by interferences. Spectrophotometric methods present a good correlation with electrochemical methods, using the same reference standards, therefore, a better comparison between methods is possible., (Copyright © 2018 Elsevier Ltd. All rights reserved.)