Host-Guest Interaction-Based Supramolecular Self-Assemblies for H2O2 Upregulation Augmented Chemiluminescence Resonance Energy Transfer-Induced Cancer Therapy

Given that light is hard to reach deep tumor tissue, how to enhance photodynamic therapy (PDT) efficacy is a big challenge. Herein, we proposed the supramolecular polymer self-assemblies (HACP) with bis[2,4,5-trichloro-6 (pentyloxycar-bonyl) phenyl] oxalate as the cargos (HACP@CPPO) to realize the chemiluminescence resonance energy transfer (CRET)-induced generation of 1O2 in situ. HACP was prepared by cinnamaldehyde-modified hyaluronic acid (HA-CA) and β-cyclodextrin-modified protoporphyrin IX (β-CD-PPIX) via host-guest interactions. The CA moiety could elevate H2O2 levels for the enhanced production of chemical energy and macrocyclic CD could enhance the stacking distance of PPIX for enhanced 1O2 yield. Thus, HACP@CPPO exhibited excellent antitumor performance without light irradiation.

A New Leaf Essential Oil from Endemic Gynoxys laurifolia (Kunth) Cass. of Southern Ecuador: Chemical and Enantioselective Analyses

The fresh leaves of Gynoxys laurifolia (Kunth) Cass. (Asteraceae), collected in the province of Loja (Ecuador), were submitted to steam distillation, producing an essential oil with a yield of 0.02% by weight. This volatile fraction, described here for the first time, was submitted to qualitative (GC-MS) and quantitative (GC-FID) chemical analyses, on two orthogonal columns (non-polar and polar stationary phase). A total of 90 components, corresponding to 95.9-95.0% by weight on the non-polar and polar stationary phase, respectively, were detected and quantified with at least one column. Major constituents (≥3%) were: germacrene D (18.9-18.0%), (E)-β-caryophyllene (13.2-15.0%), α-pinene (11.0-10.3%), β-pinene (4.5-4.4%), β-phellandrene (4.0-3.0%), bicyclogermacrene (4.0-3.0%), and bakkenolide A (3.2-3.4%). This essential oil was dominated by sesquiterpene hydrocarbons (about 45%), followed by monoterpene hydrocarbons (about 25-30%). This research was complemented with the enantioselective analysis of some common chiral terpenes, carried out through 2,3-diethyl-6-tert-butyldimethylsilyl-β-cyclodextrin and 2,3-diacetyl-6-tert-butyldimethylsilyl-β-cyclodextrin as stationary phase chiral selectors. As a result, (1S,5S)-(-)-β-pinene, (R)-(-)-α-phellandrene, (R)-(-)-β-phellandrene, (S)-(-)-limonene, (S)-(+)-linalyl acetate, and (S)-(-)-germacrene D were observed as enantiomerically pure compounds, whereas α-pinene, linalool, terpinene-4-ol, and α-terpineol were present as scalemic mixtures. Finally, sabinene was practically racemic. Due to plant wildness and the relatively low distillation yield, no industrial applications can be identified, in the first instance for this essential oil. The focus of the present study is therefore academic.

Magnetite/β-cyclodextrin/fly ash composite as an effective and recyclable adsorbent for uranium(VI) capture from wastewater

As a novel adsorbent for the separation of uranium(VI) from wastewater, Magnetite/β-cyclodextrin/fly ash composite (Fe₃O₄/β-CD/FA) was first prepared via a chemical coprecipitation technology. The characterization results indicated that Fe₃O₄ and β-CD had been successfully loaded on FA, which had brought abundant oxygen-containing functional groups, providing numerous adsorptive sites for the removal of uranium(VI). At pH = 5.0 and T = 25 °C, the maximum uranium(VI) removal efficiency and capacity of Fe₃O₄/β-CD/FA were higher to 97.8% and 444.4 mg g^-1, respectively. Pseudo-second-order and Langmuir models fitted better with the experimental data, illustrating that chemical adsorption dominated the uranium(VI) removal process. In addition, Fe₃O₄/β-CD/FA showed good anti-interference ability and recoverability. After five cycles, the removal rate of uranium(VI) on Fe₃O₄/β-CD/FA was still higher to 90.4%. The immobilization of uranium(VI) on Fe₃O₄/β-CD/FA was mainly ascribed to the synergism of redox reaction, complex reaction, chemical reaction and electrostatic interaction. Given the above, Fe₃O₄/β-CD/FA would be regarded as an efficacious, green and promising adsorbent for uranium(VI) separation from wastewater.

Adenosine/β-Cyclodextrin-Based Metal-Organic Frameworks as a Potential Material for Cancer Therapy

Recently, researchers have employed metal-organic frameworks (MOFs) for loading pharmaceutically important substances. MOFs are a novel class of porous class of materials formed by the self-assembly of organic ligands and metal ions, creating a network structure. The current investigation effectively achieves the loading of adenosine (ADN) into a metal-organic framework based on cyclodextrin (CD) using a solvent diffusion method. The composite material, referred to as ADN:β-CD-K MOFs, is created by loading ADN into beta-cyclodextrin (β-CD) with the addition of K⁺ salts. This study delves into the detailed examination of the interaction between ADN and β-CD in the form of MOFs. The focus is primarily on investigating the hydrogen bonding interaction and energy parameters through the aid of semi-empirical quantum mechanical computations. The analysis of peaks that are associated with the ADN-loaded ICs (inclusion complexes) within the MOFs indicates that ADN becomes incorporated into a partially amorphous state. Observations from SEM images reveal well-defined crystalline structures within the MOFs. Interestingly, when ADN is absent from the MOFs, smaller and irregularly shaped crystals are formed. This could potentially be attributed to the MOF manufacturing process. Furthermore, this study explores the additional cross-linking of β-CD with K through the coupling of -OH on the β-CD-K MOFs. The findings corroborate the results obtained from FT-IR analysis, suggesting that β-CD plays a crucial role as a seed in the creation of β-CD-K MOFs. Furthermore, the cytotoxicity of the MOFs is assessed in vitro using MDA-MB-231 cells (human breast cancer cells).

Synthesis and Characterization of β-Cyclodextrin-Hybridized Exfoliated Kaolinite Single Nanosheets as Potential Carriers of Oxaliplatin with Enhanced Loading, Release, and Cytotoxic Properties

Natural kaolinite was subjected to a successful exfoliation process into separated kaolinite nanosheets (KNs), followed by hybridization with β-cyclodextrin biopolymer (β-CD), forming an advanced bio-nanocomposite (β-CD/KNs). The synthetic products were evaluated as enhanced delivery structures for oxaliplatin chemotherapy (OXAPN). The hybridization of KNs with β-CD polymer notably enhanced the loading capacity to 355.3 mg/g (β-CD/KNs) as compared to 304.9 mg/g for KNs. The loading of OXAPN into both KNs and β-CD/KNs displayed traditional pseudo-first-order kinetics (R² > 0.85) and a conventional Langmuir isotherm (R² = 0.99). The synthetic β-CD/KNs validates a greater occupied effective site density (98.7 mg/g) than KNs (66.3 mg/g). Furthermore, the values of the n steric parameter (4.7 (KNs) and 3.6 (β-CD/KNs)) reveal the vertical orientation of the loaded molecules and the loading of them by multi-molecular mechanisms. These mechanisms are mainly physical processes based on the obtained Gaussian energy (<8 KJ/mol) and loading energy (<40 KJ/mol). The release profiles of both KNs and β-CD/KNs extend for about 120 h, with remarkably faster rates for β-CD/KNs. According to the release kinetic findings, the release of OXAPN displays non-Fickian transport behavior involving the cooperation of diffusion and erosion mechanisms. The KNs and β-CD/KNs as free particles showed considerable cytotoxicity and anticancer properties against HCT-116 cancer cell lines (71.4% cell viability (KNs) and 58.83% cell viability (β-CD/KNs)). Additionally, both KNs and β-CD/KNs significantly enhanced the OXAPN's cytotoxicity (2.04% cell viability (OXAPN/KNs) and 0.86% cell viability (OXAPN/β-CD/KNs).

Enhancement in the therapeutic potential of Lapatinib ditosylate against breast cancer by the use of β-cyclodextrin based ternary nanosponge system

The present investigation was performed to demonstrate the therapeutic potential of lapatinib ditosylate (LD) loaded nanosponge for the treatment of breast cancer. The study reports the fabrication of nanosponge by reaction of β-cyclodextrin with a cross-linking agent, diphenyl carbonate, at several molar ratios using the ultrasound-assisted synthesis method. The drug was loaded into the rightest nanosponge by lyophilization with and without 0.25% w/w polyvinylpyrrolidone. The significantly reduced crystallinity of developed formulations was established by differential scanning calorimetry (DSC), and powder X-ray diffractometry (PXRD). Morphological changes of LD, and formulations were compared by scanning electron microscopic (SEM) technique. Fourier transform infrared (FT-IR), and nuclear magnetic resonance (NMR) spectroscopic analysis were performed to establish the interacting groups of the host and guest molecules. It revealed interaction of the quinazoline ring, furan ring, and chlorobenzene functionality of LD with the hydroxyl group of β-cyclodextrin based nanosponge. Similar predictions were also obtained during their in-silico analysis. Saturation solubility and in vitro drug release studies revealed a 4.03-fold, and 2.43-fold rise in aqueous solubility, and dissolution of LD in the optimized formula (F2). The MCF-7 cell line study, too, revealed the higher efficiency of nanosponge formulations. The in vivo pharmacokinetic studies of optimized formulation illustrated 2.76-times, and 3.34-times enhancements in C_max and oral bioavailability, respectively. Concomitant results were obtained during the in vivo studies performed using DMBA-induced breast cancer models in female Sprague Dawley rats. The tumor burden was found to be reduced to approximately 60% by the use of F2. The hematological parameters of animals treated with F2 were also improved. Histopathology of breast tissue excised from an F2-treated rat showed a reduced size of ductal epithelial cells associated with shrunken cribriform structures and cross-bridges. The in vivo toxicity studies also showcased reduced hepatotoxicity of the formulation. Altogether, it can be concluded that encapsulation of lapatinib ditosylate in β-cyclodextrin nanosponge has improved aqueous solubility, bioavailability and, in turn, therapeutic efficacy.

Controlled Delivery of Celecoxib-β-Cyclodextrin Complexes from the Nanostructured Titanium Dioxide Layers

Considering the potential of nanostructured titanium dioxide layers as drug delivery systems, it is advisable to indicate the possibility of creating a functional drug delivery system based on anodic TiO₂ for celecoxib as an alternative anti-inflammatory drug and its inclusion complex with β-cyclodextrin. First, the optimal composition of celecoxib-β-cyclodextrin complexes was synthesized and determined. The effectiveness of the complexation was quantified using isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR) nuclear magnetic resonance (¹H NMR), and scanning electron microscopy (SEM). Then, nanostructured titanium dioxide layers (TiO₂) were synthesized using the electrochemical oxidation technique. The TiO₂ layers with pore diameters of 60 nm and layer thickness of 1.60 µm were used as drug delivery systems. The samples were modified with pure celecoxib and the β-cyclodextrin-celecoxib complex. The release profiles shown effective drug release from such layers during 24 h. After the initial burst release, the drug was continuously released from the pores. The presented results confirm that the use of nanostructured TiO₂ as a drug delivery system can be effectively used in more complicated systems composed of β-cyclodextrin-celecoxib complexes, making such drugs available for pain treatment, e.g., for orthopedic surgeries.

Sequential targeting dual-responsive magnetic nanoparticle for improved therapy of lung metastatic breast cancer

Lung metastatic breast cancer is a leading cause of cancer-related death in women and difficult to treat due to non-specific drug delivery. Herein a sequential targeting dual-responsive magnetic nanoparticle was fabricated, where Fe3O4 nanoparticle was used as magnetic core, then sequentially coated with tetraethyl orthosilicate, bis[3-(triethoxy-silyl)propyl] tetrasulfide, and 3-(trimethoxysilyl) propylmethacrylate to afford -C = C- on the surface for further polymerisation with acrylic acid, acryloyl-6-ethylenediamine-6-deoxy-β-cyclodextrin using N, N-bisacryloylcy- stamine as cross-linker, obtaining pH/redox dual-responsive magnetic nanoparticle (MNPs-CD) to delivery doxorubicin (DOX) for suppressing lung metastatic breast cancer. Our results suggested DOX-loaded nanoparticle could target the lung metastases site by sequential targeting, in which they first be delivered to the lung and even the metastatic nodules through size-driven, electrical interaction, and magnetic field-guided mechanisms, then be effectively internalised into the cancer cells followed by intelligently triggering DOX release. MTT analysis demonstrated DOX-loaded nanoparticle exhibited high anti-tumour activity against 4T1 and A549 cells. 4T1 tumour-bearing mice were employed to confirm the higher specific accumulation in lung and improved anti-metastatic therapy efficiency of DOX by focussing an extracorporeal magnetic field on the biological target. Our findings suggested the as-proposed dual-responsive magnetic nanoparticle offered a prerequisite to inhibit lung metastasis of breast cancer tumours.

Rechargeable films for protection of dry foods: A sustainable method for covalent grafting of β-cyclodextrin-thymol complex on PET/viscose platform

Rechargeable materials for the effective protection of dry food products were developed. β-cyclodextrin-thymol inclusion complex was covalently grafted on a solid platform of polyethylene terephthalate-viscose using either traditional cross-linker of epichlorohydrin, or natural cross-linker of citric acid. A correlation between the grafting method and physicochemical properties, loading capacity and release capabilities of the resulted materials was studied. The developed materials demonstrated antimicrobial properties preventing mold propagation in wheat grains. The treated grains showed normal germination abilities verifying that the prepared materials can protect dry food products without using harmful chemicals. The suggested approach can be extended to other applications and active agents. A combination of rechargeable films with natural volatiles can serve as an effective platform for sustainable active materials for food protection and in other fields such as agriculture, cosmetics, and medicine.

Inclusion Complexes of β-Cyclodextrin with Salvia officinalis Bioactive Compounds and Their Antibacterial Activities

In the present study, the formation of molecular inclusion complexes of Salvia officinalis (sage) bioactive compounds with β-cyclodextrin (β-CD) was evaluated. Sage essential oil (SEO)/β-CD inclusion complexes (ICs) were prepared by co-precipitation at iso-molecular concentrations, and Fourier transform infrared spectroscopy (FT-IR) was applied for the confirmation of the ICs' formation. Quantification of the SEO in the inclusion complexes was performed spectrophotometrically at 273 nm using an SEO standard curve. The SEO and its inclusion complexes were evaluated for their antimicrobial activity against Escherichia coli, Staphylococcus aureus and Listeria monocytogenes. The results showed that β-CD effectively formed inclusion complexes with SEO in satisfactory yields. The antimicrobial activity of the SEO in prepared complexes with β-CD was exhibited against L. monocytogenes and S. aureus and was proportional to their concentrations but was less pronounced.

Preparation and Characterization of a Nano-Inclusion Complex of Quercetin with β-Cyclodextrin and Its Potential Activity on Cancer Cells

Quercetin (QRC), a flavonoid found in foods and plants such as red wine, onions, green tea, apples, and berries, possesses remarkable anti-inflammatory and antioxidant properties. These properties make it effective in combating cancer cells, reducing inflammation, protecting against heart disease, and regulating blood sugar levels. To enhance the potential of inclusion complexes (ICs) containing β-cyclodextrin (β-CD) in cancer therapy, they were transformed into nano-inclusion complexes (NICs). In this research, NICs were synthesized using ethanol as a reducing agent in the nanoprecipitation process. By employing FT-IR analysis, it was observed that hydrogen bonds were formed between QRC and β-CD. Moreover, the IC molecules formed NICs through the aggregation facilitated by intermolecular hydrogen bonds. Proton NMR results further confirmed the occurrence of proton shielding and deshielding subsequent to the formation of NICs. The introduction of β-CDs led to the development of a distinctive feather-like structure within the NICs. The particle sizes were consistently measured around 200 nm, and both SAED and XRD patterns indicated the absence of crystalline NICs, providing supporting evidence. Through cytotoxicity and fluorescence-assisted cell-sorting analysis, the synthesized NICs showed no significant damage in the cell line of MCF-7. In comparison to QRC alone, the presence of high concentrations of NICs exhibited a lesser degree of toxicity in normal human lung fibroblast MRC-5 cells. Moreover, the individual and combined administration of both low and high concentrations of NICs effectively suppressed the growth of cancer cells (MDA-MB-231). The solubility improvement resulting from the formation of QRC-NICs with β-CD enhanced the percentage of cell survival for MCF-7 cell types.

Optimization of the Spray-Drying Encapsulation of Sea Buckthorn Berry Oil

The aim of this study was to evaluate the effect of spray-drying parameters on the physicochemical properties of encapsulated sea buckthorn berry oil. Different carriers (gum arabic, β-cyclodextrin, and their mixture (1:1, w/w)), inlet air temperatures (120, 150, and 180 °C), and carrier-to-oil ratios (2, 3, and 4, w/w) were evaluated. The obtained powders were characterized in terms of the product yield (36.79-64.60%), encapsulation efficiency (73.08-93.18%), moisture content (0.23-3.70%), hygroscopicity (1.5-7.06 g/100 g), solubility (19.55-74.70%), bulk density (0.25-0.44 g/L), total carotenoid content (mg/100 g dm), and antioxidant capacity (871.83-1454.39 μmol TE/100 g dm). All physicochemical properties were significantly affected by the carrier-to-oil ratio and inlet air temperature. Higher carrier-to-oil ratios increased the product yield, encapsulation efficiency, solubility, and bulk density and decreased the powder hygroscopicity. Elevating the drying temperatures during spray drying also increased the product yield, encapsulation efficiency, and solubility, while it decreased the powder moisture content, total carotenoid content, and antioxidant capacity. Based on the physicochemical properties, the use of β-cyclodextrin as a carrier, a drying temperature of 120 °C, and a carrier-to-oil ratio of 4 were selected as optimal conditions for the production of sea buckthorn berry oil powder. The obtained powder is a valuable material for a wide range of applications in the food and nutraceutical industries.

A highly sensitive electrochemical sensor for detecting the content of capsaicinoids based on the synergistic catalysis of rGO/PEI-CNTs/β-CD

Rapid quantification of the content of capsaicinoids helps in classifying the degree of spiciness, standardized production, and quality control of leisure meat products. To rapidly quantify the content of capsaicinoids in soy sauce and pot-roast meat products, we developed an electrochemical sensor based on reduced graphene oxide (rGO)/polyethylene imine (PEI) - carbon nanotubes (CNTs)/β-cyclodextrin (β-CD) to detect the content of capsaicinoids in leisure meat products. Our findings showed that the electrochemical sensor presented highly sensitive performance toward capsaicinoids with a relatively wide linear range (0.01-100 µmol/L), a lower limit of detection (0.01 µmol/L), and an acceptable recovery rate (94.80-112.20%). The sensor performed well and was effective mainly because of the three-dimensional stacking structure and synergistic catalysis of rGO with cCNTs and also due to the improved dispersion of the composite material by β-CD. The sensor detected trace contents of capsaicinoids in leisure meat products, and thus, it might be considered for practical applications.

Green construction of hydroxyl-functionalized magnetic porous organic framework for effective extraction of triazine herbicides from environmental water and watermelon juice samples

Triazine herbicides have been widely detected in water resources and food, which poses a potential hazard to both ecosystem and human health. Due to their high polarity, conventional adsorbents have limitations for their extractions. Herein, for the effective magnetic extraction of triazine herbicides, a novel and effective magnetic adsorbent was prepared with a satisfactory extraction performance. In the experiments, five porous organic frameworks (POFs) with hydroxyl functional groups were synthesized by diazo-coupling reactions in aqueous solution with β-cyclodextrin (β-CD) as a green monomer. After evaluation of the five POFs, the DDM-CD-POF, which was synthesized with 4'4-diaminodiphenylmethane (DDM) and β-CD, showed the largest specific surface area and the best adsorption capacity for the five triazine herbicides. Then, it was magnetized by introducing Fe₃O₄@SiO₂ into it to prepare a magnetic adsorbent (M-DDM-CD-POF) to facilitate separation and recycling. Finally, the M-DDM-CD-POF-based magnetic solid-phase extraction in combination with high performance liquid chromatographic detection method was established for the quantitative determination of the triazine herbicides in environmental water and watermelon juice samples. The current strategy showed low limits of detection of 0.03-0.11 ng mL^-1 for environmental water and 0.07-0.22 ng mL^-1 for watermelon juice sample. The method recoveries for spiked samples ranged from 84.0% to 113.0% with the relative standard deviations ≤8.8%. This work provides a new approach for the detection of the triazine herbicides with good application prospect.

β-Cyclodextrins as affordable antivirals to treat coronavirus infection

The SARS-CoV-2 pandemic made evident that there are only a few drugs against coronavirus. Here we aimed to identify a cost-effective antiviral with broad spectrum activity and high safety profile. Starting from a list of 116 drug candidates, we used molecular modelling tools to rank the 44 most promising inhibitors. Next, we tested their efficacy as antivirals against α and β coronaviruses, such as the HCoV-229E and SARS-CoV-2 variants. Four drugs, OSW-1, U18666A, hydroxypropyl-β-cyclodextrin (HβCD) and phytol, showed in vitro antiviral activity against HCoV-229E and SARS-CoV-2. The mechanism of action of these compounds was studied by transmission electron microscopy and by fusion assays measuring SARS-CoV-2 pseudoviral entry into target cells. Entry was inhibited by HβCD and U18666A, yet only HβCD inhibited SARS-CoV-2 replication in the pulmonary Calu-3 cells. Compared to the other cyclodextrins, β-cyclodextrins were the most potent inhibitors, which interfered with viral fusion via cholesterol depletion. β-cyclodextrins also prevented infection in a human nasal epithelium model ex vivo and had a prophylactic effect in the nasal epithelium of hamsters in vivo. All accumulated data point to β-cyclodextrins as promising broad-spectrum antivirals against different SARS-CoV-2 variants and distant alphacoronaviruses. Given the wide use of β-cyclodextrins for drug encapsulation and their high safety profile in humans, our results support their clinical testing as prophylactic antivirals.

Combining Blue Light and Yellow Curcumin to Obtain a "Green" Tool for Berry Preservation against Bacterial Contamination: A Preliminary Investigation

Background: According to recent studies, tens of millions of tons of fruit are wasted each year in Europe in primary production and home/service consumption. Among fruits, berries are most critical because they have a shorter shelf life and a softer, more delicate, and often edible skin. Curcumin is a natural polyphenolic compound extracted from the spice turmeric (Curcuma longa L.) which exhibits antioxidant, photophysical, and antimicrobial properties that can be further enhanced by photodynamic inactivation of pathogens when irradiated with blue or ultraviolet light. Materials and methods: Multiple experiments were performed in which berry samples were sprayed with a complex of β-cyclodextrin containing 0.5 or 1 mg/mL of curcumin. Photodynamic inactivation was induced by irradiation with blue LED light. Antimicrobial effectiveness was assessed with microbiological assays. The expected effects of oxidation, curcumin solution deterioration, and alteration of the volatile compounds were investigated as well. Results: The treatment with photoactivated curcumin solutions reduced the bacterial load (3.1 vs. 2.5 colony forming units/mL (UFC/ml) in the control and treated groups; p-value = 0.01), without altering the fruit organoleptic and antioxidant properties. Conclusions: The explored method is a promising approach to extend berries' shelf life in an easy and green way. However, further investigations of the preservation and general properties of treated berries are still needed.

Highly sensitive cholesterol concentration trace detection based on a microfiber optic-biosensor enhanced specificity with beta-cyclodextrin film

A beta-cyclodextrin (β-CD) based optic-fiber microfiber biosensor for the detection of cholesterol concentration is propose and experimentally demonstrated. As an identifying substance, β-CD is immobilized on the fiber surface for cholesterol reaction to form an inclusion complex. When the surface refractive index (RI) change is cause because of capturing the complex cholesterol (CHOL), the proposed sensor translates RI change into a macroscopic wavelength drift in the interference spectrum. The microfiber interferometer has a high RI sensitivity of 1251 nm/RIU and a low-temperature sensitivity of -0.019 nm/°C. This sensor can rapidly detect cholesterol in the concentration range of 0.001 to 1 mM and has a sensitivity of 12.7 nm/(mM) in the low concentration range of 0.001 to 0.05 mM. Finally, the characterization by infrared spectroscopy shows that the sensor can indeed detect cholesterol. This biosensor has a few strong advantages of high sensitivity and good selectivity, which expects great potential in biomedical applications.

One-pot synthesis of a novel conductive molecularly imprinted gel as the recognition element and signal amplifier for the selective electrochemical detection of amaranth in foods

Herein, we prepared a self-crosslinked conductive molecularly imprinted gel (CMIG) using cationic guar gum (CGG), chitosan (CS), β-cyclodextrin (β-CD), amaranth (AM) and multi-walled carbon nanotubes (MWCNTs) by a simple one-pot low temperature magnetic stirring method. The imine bonds, hydrogen-bonding interactions and electrostatic attractions between CGG, CS and AM facilitated CMIG gelation, while β-CD and MWCNTs enhanced the adsorption capacity and conductivity of CMIG, respectively. Next, the CMIG was deposited onto the surface of a glassy carbon electrode (GCE). After selective removal of AM, a highly sensitive and selective CMIG-based electrochemical sensor was obtained for AM determination in foods. The CMIG allowed specific recognition of AM and could also be used for signal amplification, thus improving the sensitivity and selectivity of the sensor. Due to the high viscosity and self-healing properties of the CMIG, the developed sensor was very durable retaining a 92.1% of original current after 60 consecutive measurements. Under optimal conditions, the CMIG/GCE sensor showed a good linear response for AM detection (0.02-150 μM) with a limit of detection of 0.003 μM. AM recovery tests were performed in milk powder and white vinegar samples, yielding satisfactory recoveries (89.00%-111.00%). Furthermore, the levels of AM in two kinds of carbonated drinks were analyzed with the constructed sensor and an ultraviolet spectrophotometry method, with no significant difference found of the two methods. This work demonstrates that CMIG based electrochemical sensing platforms allow the cost-effective detection of AM, with the CMIG technology likely being widely applicable to the detection of other analytes.

Tenofovir antiviral drug solubility enhancement with β-cyclodextrin inclusion complex and in silico study of potential inhibitor against SARS-CoV-2 main protease (Mpro)

Tenofovir (TFR) is an antiviral drug commonly used to fight against viral diseases infection due to its good potency and high genetic barrier to drug resistance. In physiological conditions, TFR is less water soluble, more unstable, and less permeable, limiting its effective therapeutic applications. In addition to their use in treating the Coronavirus disease 2019 (COVID-19), cyclodextrins (CDs) are also being used as a molecule to develop therapies for other diseases due to its enhance solubility and stability. This study is designed to synthesize and characterization of β-CD:TFR inclusion complex and its interaction against SARS-CoV-2 (M^Pro) protein (PDB ID;7cam). Several techniques were used to characterize the prepared β-CD:TFR inclusion complex, including UV-Visible, FT-IR, XRD, SEM, TGA, and DSC, which provided appropriate evidence to confirm the formation. A 1:1 stoichiometry was determined for β-CD:TFR inclusion complex in aqueous medium from UV-Visible absorption spectra by using the Benesi-Hildebrand method. Phase solubility studies proposed that β-CD enhanced the excellent solubility of TFR and the stability constant was obtained at 863 ± 32 M^-1. Moreover, the molecular docking confirmed the experimental results demonstrated the most desirable mode of TFR encapsulated into the β-CD nanocavity via hydrophobic interactions and possible hydrogen bonds. Moreover, TFR was validated in the β-CD:TFR inclusion complex as potential inhibitors against SARS-CoV-2 main protease (M^pro) receptors by using in silico methods. The enhanced solubility, stability, and antiviral activity against SARS-CoV-2 (M^Pro) suggest that β-CD:TFR inclusion complexes can be further used as feasible water-insoluble antiviral drug carriers in viral disease infection.

Supramolecular β-Cyclodextrin-Quercetin Based Metal-Organic Frameworks as an Efficient Antibiofilm and Antifungal Agent

The loading of drugs or medicinally active compounds has recently been performed using metal-organic frameworks (MOFs), which are thought to be a new type of porous material in which organic ligands and metal ions can self-assemble to form a network structure. The quercetin (QRC) loading and biofilm application on a cyclodextrin-based metal-organic framework via a solvent diffusion approach is successfully accomplished in the current study. The antibacterial plant flavonoid QRC is loaded onto β-CD-K MOFs to create the composite containing inclusion complexes (ICs) and denoted as QRC:β-CD-K MOFs. The shifting in the chemical shift values of QRC in the MOFs may be the reason for the interaction of QRC with the β-CD-K MOFs. The binding energies and relative contents of MOFs are considerably changed after the formation of QRC:β-CD-K MOFs, suggesting that the interactions took place during the loading of QRC. Confocal laser scanning microscopy (CLSM) showed a reduction in the formation of biofilm. The results of the cell aggregation and hyphal growth are consistent with the antibiofilm activity that is found in the treatment group. Therefore, QRC:β-CD-K MOFs had no effect on the growth of planktonic cells while inhibiting the development of hyphae and biofilm in C. albicans DAY185. This study creates new opportunities for supramolecular β-CD-based MOF development for use in biological research and pharmaceutical production.

Aided-efflux and high production of β-amyrin realized by β-cyclodextrin in situ synthesized on surface of Saccharomyces cerevisiae

As a plant-derived pentacyclic triterpenoid, β-amyrin has been heterogeneously synthesized in Saccharomyces cerevisiae. However, β-amyrin is intracellularly produced in a lower gram scale using recombinant S. cerevisiae, which limits the industrial applications. Although many strategies have been proven to be effective to improve the production of β-amyrin, the intracellularly accumulation is still a challenge in reaching higher titer and simplifying the extraction process. To solve this problem, the amphiphilic β-cyclodextrin (β-CD) has been previously employed to aid the efflux of β-amyrin out of the cells. Nevertheless, the supplemented β-CD in the medium is not consistent with β-amyrin synthesis and has the disadvantage of rather high cost. Therefore, an aided-efflux system based on in situ synthesis of β-CD was developed in this study to enhance the biosynthesis of β-amyrin and its efflux. The in situ synthesis of β-CD was started from starch by the surface displayed cyclodextrin glycosyltransferase (CGTase) on yeast cells. As a result, the synthesized β-CD could capture 16% of the intracellular β-amyrin and improve the total production by 77%. Furthermore, more strategies including inducing system remodeling, precursor supply enhancement, two-phase fermentation and lipid synthesis regulation were employed. Finally, the production of β-amyrin was increased to 73 mg/L in shake flask, 31 folds higher than the original strain, containing 31 mg/L of extracellular β-amyrin. Overall, this work provides novel strategies for the aided-efflux of natural products with high hydrophobicity in engineered S. cerevisiae.

Vacuum-assisted thermal bonding of β-cyclodextrin and its derivatives as chiral stationary phases for high-performance liquid chromatography

In this work, the vacuum-assisted thermal bonding method was proposed for the covalent coupling of β-cyclodextrin (β-CD) (CD-CSP), hexamethylene diisocyanate cross-linked β-CD (HDI-CSP) and 3, 5-dimethylphenyl isocyanate modified β-CD (DMPI-CSP) onto the isocyanate silane modified silica gel. Under vacuum conditions, the side reaction due to the water residue from the organic solvent, air, reaction vessels and silica gel could be avoided, and the optimal temperature and time of vacuum-assisted thermal bonding method were determined as 160°C and 3 h. These three CSPs were characterized by FT-IR, TGA, elemental analysis and the nitrogen adsorption-desorption isotherms. The surface coverage of CD-CSP and HDI-CSP on silica gel was determined as ∼0.2 μmol m^-2, respectively. The chromatographic performances of these three CSPs were systematically evaluated by separating 7 flavanones, 9 triazoles and 6 chiral alcohols enantiomers under the reversed-phase condition. It was found that the chiral resolution ability of CD-CSP, HDI-CSP and DMPI-CSP was complementary to each other. Among them, CD-CSP could separate all 7 flavanones enantiomers with the resolution of 1.09-2.48. HDI-CSP had a good separation performance for triazoles enantiomers with one chiral center. DMPI-CSP showed excellent separation performance for chiral alcohol enantiomers, among which the resolution of trans-1, 3-diphenyl-2-propen-1-ol reached 12.01. Generally, the vacuum-assisted thermal bonding had been demonstrated as a direct and efficient method for the preparation of chiral stationary phases of β-CD and its derivatives.

Low-pressure thin-film composite nanofiltration membranes with enhanced selectivity and antifouling property for effective dye/salt separation

For better sustainable resource recovery and elevating the separation efficiency of dye/salt mixture, it is essential to develop an appropriate nanofiltration membrane for the treatment of textile dyeing wastewater containing relatively smaller molecule dyes. In this work, a novel composite polyamide-polyester nanofiltration membrane was fabricated by tailoring amino functionalized quantum dots (NGQDs) and β-cyclodextrin (CD). An in-situ interfacial polymerization occurred between the synthesized NGQDs-CD and trimesoyl chloride (TMC) on the modified multi-carbon nanotubes (MWCNTs) substrate. The incorporation of NGQDs significantly elevated the rejection (increased by ∼ 45.08%) of the resultant membrane for small molecular dye (Methyl orange, MO) compared to the pristine CD membrane at low pressure (1.5 bar). The newly developed NGQDs-CD-MWCNTs membrane exhibited enhanced water permeability without compromising the dye rejection compared to the pure NGQDs membrane. The improved performance of the membrane was primarily attributed to the synergistic effect of functionalized NGQDs and the special hollow-bowl structure of CD. The optimal NGQDs-CD-MWCNTs-5 membrane expressed pure water permeability of 12.35 L m^-2h^-1 bar^-1 at the pressure of 1.5 bar. Noteworthily, the NGQDs-CD-MWCNTs-5 membrane not only showed high rejection for the larger molecular dye of Congo Red (CR, 99.50%) but also for the smaller molecular dye of MO (96.01%) and Brilliant Green (BG, 95.60%) with the permeability of 8.81, 11.40, and 6.37 L m^-2h^-1 bar^-1, respectively at low pressure (1.5 bar). The rejection of inorganic salts by the NGQDs-CD-MWCNTs-5 membrane was 17.20% for sodium chloride (NaCl), 14.30% for magnesium chloride (MgCl₂), 24.63% for magnesium sulfate (MgSO₄), and 54.58% for sodium sulfate (Na₂SO₄), respectively. The great rejection of dyes remained in the dye/salt binary mixed system (higher than 99% for BG and CR, <21% for NaCl). Importantly, the NGQDs-CD-MWCNTs-5 membrane exhibited favorable antifouling performance and potential good operation stability performance. Consequently, the fabricated NGQDs-CD-MWCNTs-5 membrane suggested a prospective application for the reuse of salts and water in textile wastewater treatment owing to the effective selective separation performance.

Dispersive solid phase extraction of metronidazole and clarithromycin from human plasma using a β-cyclodextrin grafted polyethylene polymer composite

In this work, for the first time, a polymeric composite based on β-cyclodextrin grafted with polyethylene has been prepared through ball milling and used as an efficient sorbent for dispersive solid phase extraction of metronidazole and clarithromycin from plasma samples. The prepared sorbent was characterized using Fourier transform infrared spectrophotometry, X-ray diffraction, and scanning electron microscopy. In the extraction process, after precipitating the proteins, the sorbent was added into the sample solution, and the mixture was vortexed to facilitate and speed up the sorption of the analytes onto the sorbent surface. After centrifuging, the sorbent particles were contacted with methanol to elute the analytes under the vortexing process. After this step, an aliquot of the eluate was taken and injected into high-performance liquid chromatography-diode array detector for quantitative analysis. Under the optimum extraction conditions, the extraction recoveries for metronidazole and clarithromycin were 76 and 83%, respectively. The limits of detection were 2.6 and 2.2 ng/ml for metronidazole and clarithromycin, respectively. The repeatability of the offered approach, expressed as relative standard deviation, was equal to or less than 4.7%. Finally, the method was successfully applied to plasma samples of the patients treated with metronidazole and clarithromycin.

[Development of PCR rapid detection method for Listeria monocytogenes in oysters]

OBJECTIVE

To develop a polymerase chain reaction(PCR) method for rapid detection of Listeria monocytogenes in oysters without pre-enrichment.

METHODS

The combination of β-cyclodextrin and bentonite-coated activated carbon was used to remove PCR inhibitors from oyster samples, and the target gene inlB was used for the PCR subsequently. The specificity, sensitivity, and application of the developed method were verified, and the stability and application of the reagents stored under cryopreservation conditions were evaluated.

RESULTS

The specificity of the developed PCR method was 100% for the detection of 130 target bacterial strains and 63 non-target bacterial strains. The method reduced the time required for Listeria monocytogenes detection to 4 h without pre-enrichment, and the detection limit was 10 CFU/25 g. The method was consistent with the conventional culture method on the detection rate and viable bacteria detection rate of Listeria monocytogenes in natural oyster samples(the coincidence rate was 100%). Additionally, the reagents could be used normally after storing at-20 ℃ for at least one year.

CONCLUSION

The PCR method developed in this study has high specificity and sensitivity, and can be used for rapid, accurate detection of Listeria monocytogenes in oysters.