The Effects of Food on Cannabidiol Bioaccessibility

Cannabidiol (CBD) is a hydrophobic non-psychoactive compound with therapeutic characteristics. Animal and human studies have shown its poor oral bioavailability in vivo, and the impact of consuming lipid-soluble CBD with and without food on gut bioaccessibility has not been explored. The purpose of this research was to study the bioaccessibility of CBD after a three-phase upper digestion experiment with and without food, and to test lipase activity with different substrate concentrations. Our results showed that lipase enzyme activity and fatty acid absorption increased in the presence of bile salts, which may also contribute to an increase in CBD bioaccessibility. The food matrix used was a mixture of olive oil and baby food. Overall, the fed-state digestion revealed significantly higher micellarization efficiency for CBD (14.15 ± 0.6% for 10 mg and 22.67 ± 2.1% for 100 mg CBD ingested) than the fasted state digestion of CBD (0.65 ± 0.7% for 10 mg and 0.14 ± 0.1% for 100 mg CBD ingested). The increase in bioaccessibility of CBD with food could be explained by the fact that micelle formation from hydrolyzed lipids aid in bioaccessibility of hydrophobic molecules. In conclusion, the bioaccessibility of CBD depends on the food matrix and the presence of lipase and bile salts.     

Allosteric Modulation of the CB1 Cannabinoid Receptor by Cannabidiol—A Molecular Modeling Study of the N-Terminal Domain and the Allosteric-Orthosteric Coupling

The CB₁ cannabinoid receptor (CB₁R) contains one of the longest N termini among class A G protein-coupled receptors. Mutagenesis studies suggest that the allosteric binding site of cannabidiol (CBD) involves residues from the N terminal domain. In order to study the allosteric binding of CBD to CB₁R we modeled the whole N-terminus of this receptor using the replica exchange molecular dynamics with solute tempering (REST2) approach. Then, the obtained structures of CB₁R with the N terminus were used for ligand docking. A natural cannabinoid receptor agonist, Δ⁹-THC, was docked to the orthosteric site and a negative allosteric modulator, CBD, to the allosteric site positioned between extracellular ends of helices TM1 and TM2. The molecular dynamics simulations were then performed for CB₁R with ligands: (i) CBD together with THC, and (ii) THC-only. Analyses of the differences in the residue-residue interaction patterns between those two cases allowed us to elucidate the allosteric network responsible for the modulation of the CB₁R by CBD. In addition, we identified the changes in the orthosteric binding mode of Δ⁹-THC, as well as the changes in its binding energy, caused by the CBD allosteric binding. We have also found that the presence of a complete N-terminal domain is essential for a stable binding of CBD in the allosteric site of CB₁R as well as for the allosteric-orthosteric coupling mechanism.     

Split intein facilitated tag affinity purification for recombinant proteins with controllable tag removal by inducible auto-cleavage

Purification tags are robust tools that can be used to purify a variety of target proteins. However, tag removal remains an expensive and significant issue that must be resolved. Based on the affinity and the trans-splicing activity between the two domains of Ssp DnaB split-intein, a novel approach for tag affinity purification of recombinant proteins with controllable tag removal by inducible auto-cleavage has been developed. This system provides a new affinity method and avoids premature splicing of the intein fused proteins expressed in host cells. The affinity matrix can be reused. In addition, this method is compatible with his-tag affinity purification technique. Our methods provide the insights for establishing a novel recombinant protein preparation system.     

Annealing effect on the structural and optical properties of a Cd1−xZnxS thin film for photovoltaic applications

Herein is a report of a study on a Cd_1−xZn_xS thin film grown on an ITO substrate using a chemical bath deposition technique. The as-deposited films were annealed in air at 400 °C for 30 min. The composition, surface morphology and structural properties of the as-deposited and annealed Cd_1−xZn_xS thin films were studied using EDX, SEM and X-ray diffraction techniques. The annealed films have been observed to possess a crystalline nature with a hexagonal structure. The optical absorption spectra were recorded within the range of 350-800 nm. The band gap of the as-deposited thin films varied from 2.46 to 2.62 eV, whereas in the annealed film these varied from 2.42 to 2.59 eV. The decreased band gap of the films after annealing was due to the improved crystalline nature of the material.     

Preparation and formation mechanism of CdS nano-films via chemical bath deposition

CdS semiconductor nano-films were grown on ITO glass substrates by means of chemical bath deposition (CBD), with Cd(NO₃)₂ as Cd ion and (NH₂)₂CS as S ion sources. The concentration of Cd ions, deposition temperature, deposition time and post-treatment temperature have an impact on the formation of CdS nano-films. UV-vis absorption spectrum and atomic force microscope (AFM) images indicated that the change of concentration and post-treatment temperature may adjust the band-gap of CdS to obtain stable, homogeneous and compact films. Formation mechanism of the crystal nucleus and CdS film was also discussed. Active sites on the surface of ITO are critical to the formation of the crystal nucleus and a uniform and compact CdS nano-film. The active site and crystal nucleus are formed due to the comprehensive effect of electricity, thermodynamics and chemistry. __________ Translated from Journal of Jilin University (Science Edition), 2007, 45(1): 116–120 [译自: 吉林大学学报(自然科学版)]     

CdS薄膜中"白斑"的研究

本论文对CdS薄膜中的"白斑"进行了研究.化学水浴沉积法(CBD)制备CdS薄膜所需要的化学反应物包括硫脲、氨水、镉盐和铵盐等.文中采用两种镉盐和铵盐来沉积CdS薄膜:氯化镉和氯化铵,乙酸镉和乙酸铵.所沉积的CdS薄膜的表观形貌由SEM表征,成分由EDX表征.当镉盐和铵盐分别采用氯化镉和氯化铵时,生成的薄膜中存在大量的"白斑".这些"白斑"的成分不是CdS,而是(CdCl)2S.增加氨水的浓度可以大大减少这些"白斑",但是不能彻底消除这些"白斑".当镉盐和铵盐分别采用乙酸镉和乙酸铵时,生成的薄膜均匀、平整,薄膜中根本就不存在所谓的"白斑".因此,沉积CdS薄膜时,镉盐和铵盐不宜采用氯化镉和氯化铵,应该采用乙酸镉和乙酸铵.     

Method validation for assay determination of cannabidiol isolates

The speed at which regulations have changed in the cannabis marketplace has increased the pressure for accurate, easy, and efficient analytical methodology. Purified isolates are used to formulate a variety of consumer products such as topicals, edibles, and beverages. Accuracy of the quantitative cannabinoid content of the isolates used in preparation of these products is directly dependent upon the reliability of the analytical methodology used for characterization. An inaccurate quantitative assay value does not only pose health, safety, and ethical concerns for consumers, it can generate a potential financial loss for manufacturers marketing isolates based upon purity. The aim of this work is to describe the validation of a rapid and reliable reversed-phase liquid chromatographic method coupled with UV detection for quantitative determination of Cannabidiol (CBD) purified isolate. Accuracy, precision, specificity, linearity, robustness and range of the analytical method were determined according to assay method requirements specified in the International Conference for Harmonization (ICH) Q2(R1), “Validation of Analytical Procedures: Test and Methodology” for quantitative evaluation of the active moiety in samples of drug substance by liquid chromatography. Additionally, the feasibility of manufacturer prepared DEA-exempt CBD reference standard solutions formulated at 1.0?mg/mL was explored for the quantification of CBD isolate.     

ZnO nanorod arrays fabrication via chemical bath deposition: Ligand concentration effect study

A new ligand, N,N,N′,N′-tetramethylethylenediamine, has been used to grow ZnO nanorods on silicon substrates via a two steps approach. A preliminary seeding on silicon substrates has been combined with chemical bath deposition using a Zinc acetate–N,N,N′,N′-tetramethylethylenediamine aqueous solution. The used diamino ligand has been selected as Zn²⁺ complexing agent and the related hydrolysis generates the reacting ions (Zn²⁺ and OH⁻) responsible for the ZnO growth. The seed layer has been annealed at low temperature (<200 °C) and the ZnO nanorods have been grown on this ZnO amorphous layer. There is experimental evidence that the ligand concentration (ranging from 5 to 50 mM) strongly affects the alignment of ZnO nanorods on the substrate, their lateral dimension and the related surface density. Length and diameter of ZnO nanorods increase upon increasing the ligand concentration, while the nanorod density decreases. Even more important, it has been demonstrated, as proof of concept, that chemical bath deposition can be usefully combined with colloidal lithography for selective ZnO nanorod deposition. Thus, by patterning the ZnO seeded substrate with polystyrene microsphere colloidal lithography, regular Si hole arrays, spatially defined by hexagonal ZnO nanorods, have been successfully obtained.     

Nanoporous nickel oxide thin films and its improved electrochromic performance: Effect of thickness

Electrochromic properties of chemically bath deposited nanoporous NiO thin films were investigated as a function of film thickness using Ni sulphate precursor, aqueous ammonia and potassium persulphate as complexing and oxidizing agents respectively. The films were characterized for their structural, morphological, optical and electrochromic properties using X-ray diffraction, scanning electron microscopy, FT-IR spectroscopy, cyclic voltammetry, chronoamperometry and optical transmittance studies. X-ray diffraction patterns show that the films are polycrystalline, consisting of NiO cubic phase. Infrared spectroscopy results show the presence of free hydroxyl ion and water in NiO thin films. SEM micrographs revealed nanoporous nature composed of interconnected nanoporous network, forming well defined 3D nano envelopes. The optical band gap energy was found to be decreased from 3.22 to 2.80 eV with increasing film thickness. The electrochromic properties of all the films were investigated in aqueous (KOH) and non aqueous (LiClO₄-PC) electrolyte by means of cyclic voltammetry (CV), chronocoulometry (CC) and optical studies. The transmittance modulations or optical density differences during the coloring/bleaching process were found to be increased with the film thickness. This increment in optical differences led to an increase in coloration efficiency (CE) to about 95 cm²/C, which is two times more than that observed in KOH and response time of 2.9 s for bleaching (reduction) and 3.5 s for coloration (oxidation) observed for the film deposited at 60 min with excellent electrochemical stability up to 3000 c/b cycles in LiClO₄-PC electrolyte.