Ultrasound processed cuminaldehyde/2-hydroxypropyl-β-cyclodextrin inclusion complex: Preparation, characterization and antibacterial activity

Synthesis, nonlinear optical activity, solvents effect, β-cyclodextrin effect, and cytotoxic activity on skin fibroblast and breast cancer cell lines of a new chalcone derivative of nabumetone

The use of small organic molecules, such as chalcones, for efficient applications as organic luminescent materials has attracted increasing attention owing to their interesting optical, photophysical, and biological properties. In this study, a new chalcone, 1-(4-isopropylphenyl)-5-(6-methoxynaphthalen-2-yl)pent-1-en-3-one (INM), was synthesized via base condensation between nabumetone and cuminaldehyde. INM was subsequently identified and characterized by FT-IR, NMR spectroscopy (1H and 13C), mass spectrometry, elemental analysis, X-ray diffraction, thermogravimetric analysis, and FESEM studies. Investigation of the solvent effect revealed that the π → π* transition involved a bathochromic shift from hexane to water and a large Stokes-shifted, twisted intramolecular charge-transfer emission in water. Diffuse reflectance spectral studies confirmed the formation of transparent INM chalcones with excellent crystallinity, and photoluminescence studies substantiated the low recombination rate of electrons and holes. Tauc plot analysis with the Kubelka-Munk algorithm revealed higher direct (3.57 eV) and indirect (3.41 eV) bandgap energies of INM. Density functional theory calculations at B3LYP/6-31G(d,p) revealed that INM had promising nonlinear optical activity (β ≈ 30.504 × 10-30 compared to a reference material, urea. Cell biocompatibility was evaluated after culturing skin fibroblasts and breast cancer cells with INM using the MTT assay and fluorescence microscopy of the live/dead cell assay. It was observed that INM exhibited good NIH/3T3 cell adhesion and proliferation and the weak inhibiting ability of MDA-MB231.

Optimization of ultrasonic-assisted debittering of Ganoderma lucidum using response surface methodology, characterization, and evaluation of antioxidant activity

Background

Ganoderma lucidum (G. lucidum) has gained increasing attention as a potential health care product and food source. However, the bitter taste of G. lucidum has limited its development and utilization for the food industry.

Methonds

The response surface methodology was employed to optimize the inclusion conditions for the debittering of G. lucidum. The effects of 2-hydroxypropyl-β-cyclodextrin concentration (12-14 g/mL), ultrasound temperature (20-40 °C and host-guest ratio (1:1-2:1) on response variables were studied. The physical characteristics of inclusion complexes prepared through spray drying and freeze drying were analyzed. The antioxidant activity of the different treated samples was subsequently investigated.

Results

Study results showed that, in comparison to the control group, the inclusion solution displayed a significantly enhanced taste profile under optimal processing conditions, exhibiting an 80.74% reduction in bitterness value. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (NMR) studies indicated the successful formation of inclusion compounds. The moisture content and bulk density of spray-dried powder were found to be significantly superior to those of freeze-dried powder (p < 0.05). In comparison to the diluted solution, the inclusion liquid demonstrated a 20.27%, 30.01% and 36.55% increase in ferric ion reducing antioxidant power (FRAP), hydroxyl radical scavenging and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging respectively. Further, the DPPH clearance of microencapsulated powder was not significantly different from that of tocopherol at a concentration of 25 mg/mL.

Conclusions

In summary, the study provides theoretical basis and methodological guidance to eliminate the bitterness of G. lucidum, and therefore provide potential options to the use of G. lucidum as a food source.

Formation of amygdalin/β-cyclodextrin derivatives inclusion complexes for anticancer activity assessment in human cervical carcinoma HeLa cell line

Nanoencapsulation has gained considerable attention because of its unique features and advantages in anticancer drug delivery. Amygdalin (AMY) is an anticancer compound, showing limitations in its applications by low stability. Herein, the inclusion complexes (ICs) of AMY with β-cyclodextrin (βCD), and its derivatives such as 2-hydroxypropyl-βCD (HPβCD) and methyl-βCD (MβCD) were fabricated. The fabricated AMY/CD-ICs were thoroughly evaluated using Fourier-transform infrared spectroscopy, powder X-ray diffraction, thermogravimetric/differential thermal analysis, proton nuclear magnetic resonance, ultraviolet-visible diffuse reflectance spectroscopy, and photoluminescence techniques. Double reciprocal profile study of the absorption and fluorescence spectra revealed that the AMY formed the ICs with βCD derivatives at a guest/host stoichiometric ratio of 1/1. The thermal stability of AMY was enhanced as the IC formation aid observed by the shift of thermal degradation temperature of AMY from the range of ∼ 220-250 °C to > 295 °C. Theoretical analyses of the energetic, electronic, and global reactivity parameters of the AMY/CD-ICs were evaluated using the PM3 method. Further assessment of the dissolution diagrams of AMY/CD-ICs revealed a burst release profile. In addition, cell toxicity was evaluated using the MTT assay, and the results showed that AMY/CD-ICs had significantly more efficacious in inhibiting HeLa cancer cells than AMY. These results proved that the IC formations with CDs significantly enhanced the anticancer activity of AMY.

Encapsulation of 4-terpineol with β-cyclodextrin: Inclusion mechanism, characterization and relative humidity-triggered release

4-Terpineol (4-TA), a typical monocyclic monoterpene essential oil compound with important biological activities, poor stability and solubility severely hamper its biological activities. To date, β-cyclodextrin (β-CD) encapsulating essential oil to form inclusion complexes (ICs) is considered as a satisfactory treatment. Nevertheless, the detailed inclusion mechanism of β-CD for 4-TA especially the behavior of 4-TA during inclusion formation have not available yet. Herein, 4-TA/β-CD ICs were successfully synthesized by the co-precipitation method, and hydrogen bonds and hydrophobic interactions played a key role in the formation of ICs, and the isopropyl of 4-TA entered the cavity through the wide rim of β-CD. Moreover, the release profile demonstrated that high RH (85 % and 99 %) triggered the release of TA from ICs. This study suggests the great potential of cyclodextrin inclusion strategy for improving the stability and sustained release of 4-TA in food preservation application.

Efficient encapsulation of Hinoki essential oil with β-cyclodextrin using an ultrasound-aided co-precipitation technique for dual anti-Listeria monocytogenes and anti-Staphylococcus aureus activities

Listeria monocytogenes (L. monocytogenes) and Staphylococcus aureus (S. aureus) are widely acknowledged as two of the most dangerous foodborne pathogens. Nevertheless, reports on the development of non-toxic food preservatives that specifically target these two bacterial strains are scarce. Here, we present an inclusion complex (IC) of Hinoki essential oil with β-cyclodextrin, which exhibited dual anti-L. monocytogenes and anti-S. aureus activities. For the first time, an innovative ultrasound-aided co-precipitation technique was utilized for the preparation of IC. Compared with the traditional co-precipitation method, this new technique demonstrated superior encapsulation and time efficiencies, making it well-suited for large-scale production. X-ray diffraction and scanning electron microscopy analyses revealed a transition in the morphological and crystal structures after formation of the IC. Fourier transform infrared spectroscopy and Raman spectroscopy analyses indicated that Hinoki essential oil was effectively encapsulated by β-cyclodextrin. The differential scanning calorimetry and thermogravimetric thermograms indicated that the formed IC was more thermally stable than the free Hinoki essential oil. Importantly, 100 % antibacterial ratios for both L. monocytogenes and S. aureus were determined, indicating that the IC prepared in this study is a promising food preservative.

Host-Guest Interactions of Caffeic Acid Phenethyl Ester with β-Cyclodextrins: Preparation, Characterization, and In Vitro Antioxidant and Antibacterial Activity

The aim of this study is to improve the solubility, chemical stability, and in vitro biological activity of caffeic acid phenethyl ester (CAPE) by forming inclusion complexes with β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (Hβ-CD) using the solvent evaporation method. The CAPE contents of the produced complexes were determined, and the complexes with the highest CAPE contents were selected for further characterization. Detailed characterization of inclusion complexes was performed by using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrospray ionization-mass spectrometry (ESI-MS). pH and thermal stability studies showed that both selected inclusion complexes exhibited better stability compared to free CAPE. Moreover, their antimicrobial activities were evaluated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) for the first time. According to the broth dilution assay, complexes with the highest CAPE content (10C/β-CD and 10C/Hβ-CD) exhibited considerable growth inhibition effects against both bacteria, 31.25 μg/mL and 62.5 μg/mL, respectively; contrarily, this value for free CAPE was 500 μg/mL. Furthermore, it was determined that the in vitro antioxidant activity of the complexes increased by about two times compared to free CAPE.

In vivo anti-obesity efficacy of fucoxanthin/HP-β-CD nanofibers in high-fat diet induced obese mice

Fucoxanthin (Fx) has poor water solubility and bioavailability, which limits its application in the food industry. To improve the physicochemical properties of Fx, hydroxypropyl-β-cyclodextrin (HP-β-CD) encapsulated Fx nanofibers (Fx/HP-β-CD nanofibers) were fabricated via electrospinning without using polymer. Molecular docking analysis showed the Fx/HP-β-CD nanofibers contained Fx and HP-β-CD at 1:2. Morphological analysis revealed the nanofibers were homogeneous without beads, having a diameter around 499 nm. The thermostability of Fx was significantly improved after encapsulationg by HP-β-CD. Animal studies showed that there was a 14% decrease of body weight, 11% white adipose tissue reduction and 9% lower of liver triglyceride for the mice treated with Fx/HP-β-CD nanofibers as compared with that of Fx treated mice. The total cholesterol was reduced by 23% in mice serum after treatment with Fx/HP-β-CD as compared with that of Fx. Interestingly, the Fx/HP-β-CD in this study could attenuate the testicular histopathology in obese mice.

Cuminaldehyde-3-hydroxy-2-napthoichydrazone: Synthesis, effect of solvents, nonlinear optical activity, antioxidant activity, antimicrobial activity, and DFT analysis

Hydrazones derived from essential oil components have attracted considerable interest because of their antimicrobial, antioxidant, and nonlinear optical applications. In the present work, a new essential oil component derivative (EOCD), cuminaldehyde-3-hydroxy-2-napthoichydrazone (CHNH), was synthesized. EOCD was characterized by Fourier transform infrared spectroscopy, mass spectrometry, nuclear magnetic resonance (1H and 13C) spectroscopy, elemental analysis, ultraviolet-visible absorption spectroscopy, and field-emission scanning electron microscopy. Thermogravimetric analysis and X-ray diffraction showed a higher stability, phase-pure, and non-existent isomorphic phase transition in EOCD. Solvent studies indicated that the normal emission band was caused by the locally excited state and the large Stokes shifted emission originated because of the twisted intramolecular charge transfer. The EOCD possessed higher direct and indirect band gap energies of 3.05 eV and 2.90 eV respectively, as determined by the Kubelka-Munk algorithm. The outcomes of frontier molecular orbitals, global reactivity descriptors, Mulliken, and molecular electrostatic potential surface by density functional theory calculations revealed high intramolecular charge transfer, good realistic stability, and high reactiveness of EOCD. The hydrazone EOCD exhibited higher hyperpolarizability (18.248 × 10-30 esu) in comparison to urea. Antioxidant test results indicated that EOCD showed significant antioxidant activity (p < 0.05), as determined by the DPPH radical scavenging assay. The newly synthesized EOCD showed no antifungal activity against Aspergillus flavus. Additionally, the EOCD showed good antibacterial activity against Escherichia coli and Bacillus subtilis.

Cyclodextrin inclusion complexes improving antibacterial drug profiles: an update systematic review

Aim: The study aimed to review experimental models using cyclodextrins to improve antibacterial drugs' physicochemical characteristics and biological activities. Methods: The following terms and their combinations were used: cyclodextrins and antibacterial agents in title or abstract, and the total study search was conducted over a period up to October 2022. The review was carried out using PubMed, Scopus and Embase databases. A total of 1580 studies were identified, of which 27 articles were selected for discussion in this review. Results: The biological results revealed that the antibacterial effect of the inclusion complexes was extensively improved. Cyclodextrins can enhance the therapeutic effects of antibiotics already existing on the market, natural products and synthetic molecules. Conclusion: Overall, CDs as drug-delivery vehicles have been shown to improve antibiotics solubility, stability, and bioavailability, leading to enhanced antibacterial activity.

Preparation of Green Anti-Staphylococcus aureus Inclusion Complexes Containing Hinoki Essential Oil

This study aimed to prepare anti-Staphylococcus aureus inclusion complexes (ICs) of Hinoki essential oil (HEO) with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD). An ultrasound-assisted kneading method was applied for the complexation for the first time. The recovery yield, embedding fraction and loading capacity of the HEO/β-CD ICs were 92.5%, 78.0% and 11.9%, respectively, while the corresponding values were 80.8%, 73.7% and 12.9% for the HEO/2-HP-β-CD ICs. As well, a comparative study confirmed the efficiency of the ultrasound-assisted kneading method was higher than the traditional kneading method. The results of SEM, XRD, GC-MS and FT-IR suggested the successful formation of ICs. A significant anti-Staphylococcus aureus activity of the fabricated ICs was demonstrated using a colony counting method. Notably, when the dose in liquid culture medium was 20 g L-1, inhibitory rates of 99.8% for HEO/β-CD ICs and 100% for HEO/2-HP-β-CD ICs were achieved. Furthermore, the hydrophilic property of the ICs was proved by water contact angle measurements, implying they have the potential to act as anti-Staphylococcus aureus agents for blending with hydrophilic biodegradable materials for diverse food packaging utilizations.

Characterization, Thermal Stability and Antimicrobial Evaluation of the Inclusion Complex of Litsea cubeba Essential Oil in Large-Ring Cyclodextrins (CD9-CD22)

Food safety issues are becoming increasingly important as a result of contamination with foodborne pathogenic bacteria. Plant essential oil is a safe and non-toxic natural antibacterial agent that can be used to develop antimicrobial active packaging materials. However, most essential oils are volatile and require protection. In the present study, LCEO and LRCD were microencapsulated through coprecipitation. The complex was investigated using GC-MS, TGA, and FT-IR spectroscopy. According to the experimental results, it was found that LCEO entered the inner cavity of the LRCD molecule and formed a complex with LRCD. LCEO had a significant and broad-spectrum antimicrobial effect against all five microorganisms tested. At 50 °C, the microbial diameter of the essential oil and its microcapsules showed the least change, indicating that this essential oil has high antimicrobial activity. In research on microcapsule release, LRCD has proven to be a perfect wall material for controlling the delayed release of essential oil and extending the duration of antimicrobial activity. LRCD effectively extends antimicrobial duration by encasing LCEO, thus improving its heat stability and antimicrobial activity. The results presented here indicate that LCEO/LRCD microcapsules can be further utilized in the food packaging industry.

Fabrication of a Dual-Drug-Loaded Smart Niosome-g-Chitosan Polymeric Platform for Lung Cancer Treatment

Changes in weather conditions and lifestyle lead to an annual increase in the amount of lung cancer, and therefore it is one of the three most common types of cancer, making it important to find an appropriate treatment method. This research aims to introduce a new smart nano-drug delivery system with antibacterial and anticancer capabilities that could be applied for the treatment of lung cancer. It is composed of a niosomal carrier containing curcumin as an anticancer drug and is coated with a chitosan polymeric shell, alongside Rose Bengal (RB) as a photosensitizer with an antibacterial feature. The characterization results confirmed the successful fabrication of lipid-polymeric carriers with a size of nearly 80 nm and encapsulation efficiency of about 97% and 98% for curcumin and RB, respectively. It had the Korsmeyer-Peppas release pattern model with pH and temperature responsivity so that nearly 60% and 35% of RB and curcumin were released at 37 °C and pH 5.5. Moreover, it showed nearly 50% toxicity against lung cancer cells over 72 h and antibacterial activity against Escherichia coli. Accordingly, this nanoformulation could be considered a candidate for the treatment of lung cancer; however, in vivo studies are needed for better confirmation.

Comparison of the Conventional and Mechanochemical Syntheses of Cyclodextrin Derivatives

Many scientists are working hard to find green alternatives to classical synthetic methods. Today, state-of-the-art ultrasonic and grinding techniques already drive the production of organic compounds on an industrial scale. The physicochemical and chemical behavior of cyclodextrins often differs from the typical properties of classic organic compounds and carbohydrates. The usually poor solubility and complexing properties of cyclodextrins can require special techniques. By eliminating or reducing the amount of solvent needed, green alternatives can reform classical synthetic methods, making them attractive for environmentally friendly production and the circular economy. The lack of energy-intensive synthetic and purification steps could transform currently inefficient processes into feasible methods. Mechanochemical reaction mechanisms are generally different from normal solution-chemistry mechanisms. The absence of a solvent and the presence of very high local temperatures for microseconds facilitate the synthesis of cyclodextrin derivatives that are impossible or difficult to produce under classical solution-chemistry conditions. Although mechanochemistry does not provide a general solution to all problems, several good examples show that this new technology can open up efficient synthetic pathways.

Chrysin-phospholipid complex-based solid dispersion for improved anti-aging and neuroprotective effects in mice

The present study aimed to improve the neuroprotective effect of chrysin (CHR) by combining two formulation techniques, phospholipid (PL) complexation and solid dispersion (SD). CHR-phospholipid complex (CHR-PLC) was prepared through solvent evaporation. The molar ratio CHR/PL (1:3), which exhibited the highest complexation efficiency, was selected for the preparation of CHR-PLC loaded SD (CHR-PLC-SD) with 2-hydroxypropyl β cyclodextrin (2-HPβCD) and polyvinylpyrrolidone 8000. CHR-PLC/2-HPβCD (1:2, w/w) displayed the highest aqueous solubility of CHR (5.86 times more than that of plain CHR). CHR-SD was also prepared using 2-HPβCD for comparison. The in vitro dissolution of CHR-PLC-SD4 revealed an enhancement in the dissolution rate over CHR-PLC (1:3), CHR-SD, and plain CHR by six times. The optimum formulations and plain CHR were evaluated for their neuroprotective effect on brain aging induced by D-galactose in mice. The results demonstrated a behavioral activity elevation, an increase of AMPK, LKB1, and PGC1α brain contents as well as a reduction of AGEs, GFAP, NT-3, TNF-α, and NF-κβ brain contents when compared with those of the D-galactose control group. Thus, the developed formulations stimulated neurogenesis and mitochondrial biogenesis as well as suppressed neuroinflammation and neurodegeneration. The order of activity was as follows: CHR-PLC-SD4 > CHR-PLC (1:3) > CHR-SD > plain CHR.

Encapsulation of Benzyl Isothiocyanate with β-Cyclodextrin Using Ultrasonication: Preparation, Characterization, and Antibacterial Assay

Benzyl isothiocyanate (BITC) is widely utilized in multiple biomedical fields, due to its significant antibacterial properties and low toxicity. However, poor water solubility and pungent odor has limited its application in the food industry. In this study, we first prepared inclusion complexes of BITC in GLU-β-CD and HP-β-CD using ultrasound, which is able to overcome the hindrance of poor water solubility and high volatility. Then, the BITC-β-CD inclusion complexes were characterized by using high-performance liquid chromatography (HPLC), nuclear magnetic resonance hydrogen spectra (¹H-NMR), infrared absorption spectra (IR), and differential scanning calorimetry (DSC) to confirm their stability. Further, the evaluation of antibacterial and antitumor effects of the BITC-β-CD inclusion complexes showed that they had great bactericidal activity against both Escherichia coli and Staphylococcus aureus cells, and also inhibited the growth of HepG2 cells in vitro. In addition, our results indicated that BITC-β-CD complexes were able to inhibit the growth of S. aureus in broccoli juice and extend the shelf life of broccoli juice, demonstrating the potential of β-cyclodextrin to improve the stability and controlled release of BITC. Taken together, our results show that BITC-β-CD complexes have good potential for application in the food industry.

Fabrication of fucoxanthin/2-hydroxypropyl-β-cyclodextrin inclusion complex assisted by ultrasound procedure to enhance aqueous solubility, stability and antitumor effect of fucoxanthin

Fucoxanthin (Fx) possesses multiple bioactivities such as antitumor, antioxidant and anti-inflammatory activities, but its application is limited due to the poor water solubility, low bioavailability, and instability to some external harsh conditions. In this study, a stable inclusion complex of Fx and 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) was prepared with the aid of ultrasound, which was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, powder X-ray diffraction, and differential scanning calorimetry techniques. The phase solubility analysis and absorption spectroscopy results showed that Fx formed stoichiometry 1:2 inclusion complex with 2-HP-β-CD, and this could be well proved by molecular simulation. Structural analyses and molecular docking study indicated that Fx was successfully encapsulated into the cavity of 2-HP-β-CD, promoting it soluble in water and stable against heat, storage and gastrointestinal environments. In addition, Fx/2-HP-β-CD inclusion complex exhibited excellent antitumor activity against HCT116 and Caco-2 cell lines with IC₅₀ values of 12.0 μΜ and 14.86 μΜ, respectively. Therefore, it could be a potentially promising way to promote the application of Fx in pharmaceuticals and functional foods by HP-β-CD encapsulation strategy.

Development of pediatric orally disintegrating mini-tablets containing atomoxetine hydrochloride-β-cyclodextrin inclusion complex using experimental design

OBJECTIVE

The aim of the study was to develop and evaluate characteristics of orally disintegrating mini-tablet (ODMT) formulations including atomoxetine hydrochloride (ATO)/β-cyclodextrin (β-CD) inclusion complex for pediatric therapy of attention deficit and hyperactivity disorder (ADHD).

METHODS

Design of experiment approach was used to develop ODMTs. The ODMTs were compressed using direct compression method with two different superdisintegrants (Parteck ODT^® and Ac-Di-Sol^®) and characterized with quality control tests. In vitro dissolution and taste studies were performed.

RESULTS

The hardness and friability values of the optimized three ODMT formulations were determined as 41.7 N, 42.4 N, and 40.8 N and 0.32%, 0.29%, and 0.42%, respectively. The disintegration time of all the optimized formulations was found to be less than one minute. In addition, dissolution profiles of ATO from optimized ODMTs were determined in four different dissolution media (distilled water, pH 1.2, 6.8, and 7.4) and it was determined that the maximum dissolved ATO amount reached at the end of 20 min.

CONCLUSION

As a conclusion, the novel formulation of ODMTs with ATO/β-CD inclusion complex was successfully developed for pediatric use.

Quercitrin loaded cyclodextrin based nanosponge as a promising approach for management of lung cancer and COVID-19

Lung cancer and pandemic acute respiratory disease, COVID-19, are examples of the most worldwide widespread diseases. The aim of the current study is to develop cyclodextrin based nanosponge (CD-NS) for loading the flavonoid drug, quercitrin (QCT). This is to improve its solubility in an attempt to enhance its activity against lung cancer as well as SARS-CoV-2 virus responsible for COVID-19. Preparation of CD-NS was performed by ultrasound-assisted synthesis method. Two CDs were employed, namely, β cyclodextrin (βCD) and 2-hydroxy propyl-β-cyclodextrin (2-HPβCD) that were crosslinked with diphenyl carbonate, one at a time. QCT loaded CD-NS revealed entrapment efficiency and particle size ranged between 94.17 and 99.03% and 97.10–325.90 nm, respectively. QCT loaded 2-HPβCD-NS revealed smaller particle size compared with that of QCT loaded βCD-NS. Zeta potential absolute values of the prepared formulations were >20 mV, indicating physically stable nanosystems. The selected formulations were investigated by Fourier transform infrared spectroscopy, X-ray powder diffraction and scanning electron microscopy which proved the formation of QCT loaded CD-NS exhibiting porous structure. QCT exhibited partial and complete amorphization in βCD-NS and 2-HPβCD-NS, respectively. In vitro release revealed an improved release of QCT from CD-NS formulations. The biological activity of free QCT and QCT loaded CD-NS was investigated against lung cancer cell line A549 as well as SARS-CoV-2 virus. The results revealed that IC₅₀ values of free QCT against lung cancer cell line A549 and SARS-CoV-2 were higher than those exhibited by QCT loaded CD-NS by 1.57–5.35 and 5.95–26.95 folds, respectively. QCT loaded 2-HPβCD-NS revealed enhanced in vitro release and superior biological activity compared with QCT loaded βCD-NS.

Preparation, characterization, and antifungal property of the inclusion complex of Litsea cubeba essential oil/hydroxypropyl-β-cyclodextrin and its application in preservation of Shatang mandarin

To explore the potential application of plant essential oil in the postharvest preservation of fruits, the inclusion complex (IC) of Litsea cubeba essential oil (LCEO) with hydroxypropyl-β-cyclodextrin (HPβCD), prepared by the saturated aqueous solution method, was studied. LCEO/HPβCD-IC was characterized by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size distribution, and thermogravimetric-differential scanning calorimetry (TG-DSC) analysis. The formation of LCEO/HPβCD-IC was confirmed, and the volume average particle diameter was 24.376 µm. Due to the inclusion of HPβCD, the volatility of LCEO was significantly reduced and the thermal stability was significantly improved. In addition, the antifungal activities of the LCEO ICs were compared, and LCEO/HPβCD-IC was more effective against the citrus postharvest pathogens (P. italicum and G. citri-aurantii). The effects of the LCEO ICs on the postharvest quality of Shatang mandarin were studied. Compared with the control group (CK) and LCEO/βCD-IC group, the LCEO/HPβCD-IC group showed a significant delay in the decrease of good fruit rate, hardness, total soluble solids (TSSs), and Vitamin C (Vc) content, with a lower weight loss rate of Shatang mandarin. Therefore, LCEO/HPβCD-IC is expected to be used as a green preservative for the storage and preservation of citrus fruits. PRACTICAL APPLICATION: In this study, LCEO was encapsulated in HPβCD by the saturated aqueous solution method and the prepared inclusion complex was characterized. The effects of LCEO/HPβCD-IC and LCEO/βCD-IC on postharvest preservation of Shatang mandarin were compared. This work offers valuable insights into the postharvest preservation of citrus fruit by essential oil inclusion complexes.

β-cyclodextrin microencapsulation enhanced antioxidant and antihyperlipidemic properties of Tunisian Periploca angustifolia roots condensed tannins in rats

This study aimed to investigate the microencapsulation of novel condensed tannins isolated from Periploca angustifolia roots, using β-cyclodextrin macrocyclic oligosaccharides, in order to enhance their antioxidant and antihyperlipidemic potentials. Scanning electron microscopy and Fourier transform infrared spectroscopy results revealed that tannin fraction was successfully included into β-cyclodextrin cavities proved with an encapsulation efficacy of 70%. Our in vitro findings highlighted that both pure and encapsulated tannins have efficient inhibition capacities of pancreatic lipase activity. However, the inclusion complex has the greatest, in vivo, antioxidant, and antihyperlipidemic effects. In fact, results showed that complexed tannins had markedly restored serum lipid biomarkers, lipid peroxidation, protein carbonyl oxidation, and antioxidant enzyme defense. These findings were additionally confirmed by aortic and myocardial muscle sections of histological examination. Consequently, β-cyclodextrin microencapsulation may be considered as an effective and promising technique for tannin delivery with improved antioxidant and antihyperlipidemic activities.

Controlled release and antibacterial properties of PEO/casein nanofibers loaded with Thymol/β-cyclodextrin inclusion complexes in beef preservation

There are still many limitations in the application of natural active compounds in meat preservation. Herein, thymol was first inserted into the cavity of β-cyclodextrin (β-CD) to form a stable inclusion complex (THY/β-CD-IC). The computational investigation showed that the optimized complexation energy for THY/β-CD-IC was -12.95 kcal mol^-1. It contributed to the improvement of the thermal stability of thymol in the inclusion compound. Furthermore, the functionalized nanofibers (THY/β-CD-IC-NFs) loaded with THY/β-CD-IC were successfully fabricated by electrospinning of the mixture of casein and polyethylene oxide. When dealing with protease-producing bacteria, controllable release of thymol from THY/β-CD-IC-NFs was achieved through the response of casein to the hydrolysis of bacterial protease. The application results indicated that the prepared THY/β-CD-IC-NFs had a long-term antimicrobial activity for chilled beef preservation during 7-days storage. The information from this study presents a feasible strategy for the development of natural extracts for use in meat preservation.

Enhanced antibacterial activity of levofloxacin/hydroxypropyl-β-cyclodextrin inclusion complex: In vitro and in vivo evaluation

Levofloxacin is the levo-enantiomer of ofloxacin (a fluoroquinolone class of antibacterial drug). Cyclodextrins (CDs) including hydroxypropyl-β-cyclodextrin (HPβCD) are generally used as a chiral selector for the enantioseparation of some drugs including levofloxacin or as a drug/food nanocarrier for the efficacy improvement of many pharmaceuticals. We hypothesized that the cyclodextrin inclusion is potentially able to further improve the antibacterial activity of levofloxacin. To test this hypothesis, the levofloxacin/HPβCD inclusion complex was prepared by the freeze-drying method and characterized by phase solubility diagram, differential scanning calorimetry (DSC), X-ray diffractometry (XRD), UV-Vis spectrophotometer, and ¹H NMR spectroscopy, confirming the successful HPβCD inclusion of levofloxacin. The in vitro antibacterial effects of HPβCD, levofloxacin, and the levofloxacin/HPβCD inclusion complex against four different bacterial strains in liquid media and on agar plates were determined/compared (an MIC₉₀ of 0.5-1.0 μg/mL for the inclusion complex compared with that of 1.0-2.0 μg/mL for free levofloxacin in liquid). Moreover, the in vivo antibacterial effects of levofloxacin and levofloxacin/HPβCD inclusion complex were tested by using a skin scald model in mice infected with Staphylococcus aureus, and decreased amounts of both bacteria and leukocytes were detected in scalded skin after the inclusion complex treatment. The data revealed that the levofloxacin/HPβCD inclusion complex had an enhanced antibacterial activity compared with free levofloxacin. It implies that cyclodextrins (e.g. HPβCD) may have a beneficial role when using as a chiral selector or as a drug nanocarrier for levofloxacin and that the levofloxacin/HPβCD inclusion complex has the potential of being developed into a pharmaceutical for antibacterial therapies.

Development of active packaging films based on liquefied shrimp shell chitin and polyvinyl alcohol containing β-cyclodextrin/cinnamaldehyde inclusion

To maintain the freshness of fruits and to meet environmental and consumer needs, a biobased packaging film with long-lasting antimicrobial activity was developed in this article. Liquefied ball-milled shrimp shell chitin/polyvinyl alcohol (LBSC/PVA) blend films containing varying concentrations (0, 1, 2, 3, 4, 5 wt%) of the β-cyclodextrin/cinnamaldehyde (β-CD/CA) inclusion were prepared and characterized. The association between β-CD and CA and the sustained release behavior of CA were explored. The physicochemical property, antimicrobial activity and food preservation performance of the films were investigated. Results showed that CA was successfully encapsulated into the cavity of CD by host-guest interactions, which greatly improved the sustained release of CA. The 3 wt% β-CD/CA/LBSC/PVA blend film showed optimized mechanical properties with a tensile strength of 41.5 MPa and an elongation at break of 810 %. In addition, the incorporation of β-CD/CA inclusion significantly enhanced the antimicrobial activity and food preservation performance of the blend films. Moreover, the 3 wt% β-CD/CA/LBSC/PVA blend film exhibited evidently longer lasting antimicrobial activity and cherry tomato preservation performance than the 3 wt% CA/LBSC/PVA blend film, further demonstrating the critical role of β-CD in delaying CA release. These novel β-CD/CA/LBSC/PVA blend films may have a potential use in active food packaging.

Development of Cyclodextrin-Functionalized Transethoniosomes of 6-Gingerol: Statistical Optimization, In Vitro Characterization and Assessment of Cytotoxic and Anti-Inflammatory Effects

The poor solubility and stability of 6-gingerol (6-G) could hamper its clinical applications. The aim of the current study was to develop a novel ultra-deformable cyclodextrin-functionalized transethoniosomes (CD-TENs) as a promising delivery system for 6-G. Transethoniosomes (TENs) are flexible niosomes (NVs) due to their content of ethanol and edge activators (EAs). CD-functionalized nanoparticles could improve drug solubility and stability compared to the corresponding nanovesicles. 6-G-loaded ethoniosomes (ENs) were formulated by the ethanol injection technique in the presence and absence of EA and CD to explore the impact of the studied independent variables on entrapment efficiency (EE%) and % 6-G released after 24 h (Q_24h). According to the desirability criteria, F8 (CD-functionalized transethoniosomal formula) was selected as the optimized formulation. F8 demonstrated higher EE%, permeation, deformability and stability than the corresponding TENs, ENs and NVs. Additionally, F8 showed higher cytotoxic and anti-inflammatory activity than pure 6-G. The synergism between complexation with CD and novel ultra-deformable nanovesicles (TENs) in the form of CD-TENs can be a promising drug delivery carrier for 6-G.

Computational Methods for the Interaction between Cyclodextrins and Natural Compounds: Technology, Benefits, Limitations, and Trends

Cyclodextrins (CDs) have a hollow structure with a hydrophobic interior and hydrophilic exterior. Forming inclusion complexes with CDs will maximize the bioavailability of natural compounds and enable active components to be processed into functional foods, medicines, additives, and so forth. However, experimental methods cannot explain CD-guest binding at the atomic level. Different models have been recently developed to simulate the interaction between CDs and guests to study the binding conformation and analyze noncovalent forces. This review paper summarizes modeling methods of CD-natural compound complexes. The methods include quantitative structure-activity relationships, molecular docking, molecular dynamics simulations, and quantum-chemical calculations. The applications of these methods to enhance the solubility and bioactivities of guest molecules, assist material transportation, and promote compound extraction are also discussed. The purpose of this review is to explore interaction mechanisms of CDs and guests and to help expand new applications of CDs.

Molecular insight into the interactions between starch and cuminaldehyde using relaxation and 2D solid-state NMR spectroscopy

The interaction between cuminaldehyde and starch mainly governed the effect of further handling on food applications of cuminaldehyde. However, little information is available about the interactions of these components. We utilized relaxation and heteronuclear correlation (HETCOR) solid-state NMR spectroscopy to investigate the interaction between cuminaldehyde and porous starch at molecular level. We found that the interactions occurred mainly through hydrogen bonds. Cuminaldehyde molecules were restricted by starch, which resulted in the limitation of their movements and the longer ¹H T₁ relaxation time. Furthermore, the well resolved correlated peaks in 2D ¹H-¹³C HETCOR spectrum confirmed the formation of hydrogen bonds. The oxygen atoms at hydroxyl-2,3 of starch were the binding sites, which combined with hydrogens of cuminaldehyde. This present work not only afford a new approach to obtain a molecular understanding of interactions, but also expanded the application of solid-state NMR to investigation of the interaction on functional components.

Improvement of betalains stability extracted from red dragon fruit peel by ultrasound-assisted microencapsulation with maltodextrin

Natural betalains can be potential food additives because of their antioxidant activities, but they have poor thermal stability. In this study, betalains were extracted from red dragon fruit peel, and then encapsulated with maltodextrin by ultrasound method to increase the physicochemical properties of betalains microcapsules. The encapsulation efficiency of the betalains was above 79%, and the particle size and Zeta potential values were 275.46 nm and -29.01 mV, respectively. Compared to the control sample, onset temperature and DPPH free radical scavenging of betalains microcapsules under the modest ultrasound treatment (200 W, 5 min) was increased by 1.6 °C and 12.24%, respectively. This increase could be due to the ability of ultrasonification to create interactions between maltodextrin and betalains (as evidenced by FT-IR). Therefore, modest ultrasound treatment can be used for microcapsulation to improve the stability of betalains, and then expand the application of betalains in heat processed food field.

Rational formulation engineering of fraxinellone utilizing 6-O-α-D-maltosyl-β-cyclodextrin for enhanced oral bioavailability and hepatic fibrosis therapy

Although Fraxinellone (Frax) isolated from Dictamnus albus L. possessed excellent anti-hepatic fibrosis activity, oral administration of Frax suffered from the inefficient therapeutic outcome in vivo due to negligible oral absorption. At present, the oral formulation of Frax is rarely exploited. For rational formulation design, we evaluated preabsorption risks of Frax and found that Frax was rather stable while poorly dissolved in the gastrointestinal tract (78.88 μg/mL), which predominantly limited its oral absorption. Further solubility test revealed the outstanding capacity of cyclodextrin derivatives (CDs) to solubilize Frax (6.8-12.8 mg/mL). This led us to study the inclusion complexes of Frax with a series of CDs and holistically explore their drug delivery performance. Characterization techniques involving ¹H-NMR, FT-IR, DSC, PXRD, and molecular docking confirmed the most stable binding interactions when Frax complexed with 6-O-α-D-maltosyl-β-cyclodextrin (G₂-β-CD-Frax). Notably, G₂-β-CD-Frax exhibited the highest solubilizing capacity, fast dissolution rate, and superior Caco-2 cell internalization with no obvious toxicity. Pharmacokinetic studies demonstrated markedly higher oral bioavailability of G₂-β-CD-Frax (5.8-fold that of free drug) than other Frax-CDs. Further, long-term administration of G₂-β-CD-Frax (5 mg/kg) efficiently inhibited CCl₄-induced hepatic fibrosis in the mouse without inducing any toxicity. Our results will inspire the continued advancement of optimal oral Frax formulations for anti-fibrotic therapy.

Association of antioxidant monophenolic compounds with β-cyclodextrin-functionalized cellulose and starch substrates

Polysaccharide substrates loaded with antioxidant and antimicrobial compounds, effectively protected by cyclodextrin moieties, can be a long-lasting solution to confer certain properties to fabrics, paper and other materials. β-Cyclodextrin was attached to α-cellulose, bleached pulp and starch by a two-step esterification with a tetracarboxylic acid. The resulting derivatives were characterized by spectroscopy, thermal degradation analysis and capability of phenolphthalein inclusion. The carriers, containing between 89 and 171 μmol of β-cyclodextrin per gram, were loaded with carvacrol, cuminaldehyde, cinnamaldehyde and hydroxytyrosol. From a stoichiometric addition, the percentage of compound retained ranged from 49% (hydroxytyrosol in pulp-cyclodextrin) to 92% (carvacrol in starch-cyclodextrin). Finally, the release rate to aqueous ethanol was measured over eight days and fitted to kinetic models. From the analysis of the mean dissolution time, it can be concluded that inserting β-cyclodextrin units enhanced the long-term holding of phenolic active compounds in carbohydrate matrices.

Toward a Greener World-Cyclodextrin Derivatization by Mechanochemistry

Cyclodextrin (CD) derivatives are a challenge, mainly due to solubility problems. In many cases, the synthesis of CD derivatives requires high-boiling solvents, whereas the product isolation from the aqueous methods often requires energy-intensive processes. Complex formation faces similar challenges in that it involves interacting materials with conflicting properties. However, many authors also refer to the formation of non-covalent bonds, such as the formation of inclusion complexes or metal–organic networks, as reactions or synthesis, which makes it difficult to classify the technical papers. In many cases, the solubility of both the starting material and the product in the same solvent differs significantly. The sweetest point of mechanochemistry is the reduced demand or complete elimination of solvents from the synthesis. The lack of solvents can make syntheses more economical and greener. The limited molecular movements in solid-state allow the preparation of CD derivatives, which are difficult to produce under solvent reaction conditions. A mechanochemical reaction generally has a higher reagent utilization rate. When the reaction yields a good guest co-product, solvent-free conditions can be slower than in solution conditions. Regioselective syntheses of per-6-amino and alkylthio-CD derivatives or insoluble cyclodextrin polymers and nanosponges are good examples of what a greener technology can offer through solvent-free reaction conditions. In the case of thiolated CD derivatives, the absence of solvents results in significant suppression of the thiol group oxidation, too. The insoluble polymer synthesis is also more efficient when using the same molar ratio of the reagents as the solution reaction. Solid reactants not only reduce the chance of hydrolysis of multifunctional reactants or side reactions, but the spatial proximity of macrocycles also reduces the length of the spacing formed by the crosslinker. The structure of insoluble polymers of the mechanochemical reactions generally is more compact, with fewer and shorter hydrophilic arms than the products of the solution reactions.

Allicin inclusions with α-cyclodextrin effectively masking its odor: Preparation, characterization, and olfactory and gustatory evaluation

Allicin, a chemical found in functional foods, has a variety of beneficial bioactivities but the unpleasent odor and unstability hinder its applications. Isolating products from cyclodextrin (CD) complexation, using β-CD and its derivatives, is usually a time and energy-consuming process. Herein, a high-efficiency and eco-friendly preparation method of an inclusion (allicin@α-CD) formed by allicin and α-CD was designed, which turned liquid allicin into crystal particles with high-speed stirring (10,000 r/min) at 25°C for 10 min in water. In vivo and in vitro masking evaluations showed that the inclusion particles could decrease the unpleasant odor of allicin. Molecular docking and experimental characterization results illustrated that the main reason of odor masking was due to the disulfide and thiocarbonyl groups of allicin being partially encapsulated by the cavity of α-CD. Compared with the physical mixture, the stability of allicin in allicin@α-CD at 60°C for 10 days was 33-fold improved. Overall, this efficient strategy of inclusion provided a promising approach for the industrialization of allicin-related formulations. PRACTICAL APPLICATION: In this study, an environmentally friendly method of α-CD inclusion without the use of organic reagents was designed to solidify and stabilize allicin, which effectively masked the unpleasant odor and taste of allicin. It has contributed greatly to improving the compliance of consumers and provided a new and effective approach to broaden the application of allicin.

Benzimidazole loaded β-cyclodextrin as a novel anti-corrosion system; coupled experimental/computational assessments

HYPOTHESIS

Silane (sol-gel)-based coatings have been introduced as an eco-friendly system for reducing the metals' corrosion in NaCl solutions. However, due to the lack of active protection property for this type of coatings, their modification is totally recommended for achieving durable protection properties. The present study introduces Beta-cyclodextrin (β-CD) as a novel/effective organic nano-container for Benzimidazole (BM) encapsulation to obtain reliable active protection property via a controlled-release property.

EXPERIMENTS

The chemical structure of the β-CD-BM macromolecule was explored by Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD), and Ultraviolet-visible spectroscopy (UV-Vis). Besides, the Electrochemical Impedance Spectroscopy (EIS) and polarization (potentiodynamic) tests were carried out for investigating the inhibition impacts of the constructed containers. The exposed and unexposed samples' surfaces were analyzed by Field Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive Spectroscopy (EDS)/mapping, and Grazing incidence X-ray diffraction (GIXRD) experiments. Also, the EIS test was conducted over the Silane-based composite film (SCF) for analyzing the anti-corrosion performance of the constructed composites.

FINDINGS

The EIS achievements demonstrated that by the addition of β-CD-BM complexes to the saline solution, the mild steel corrosion was mitigated by about 84%. The EIS results also displayed that the total resistance of the modified composite was enhanced from 5540 Ω.cm² to 10967 Ω.cm² and the intact coating provided a total resistance of 80254 Ω.cm². The dispersion-corrected Density Functional Theory (DFT)-D explorations ascertained the inclusion capacity of benzimidazole inside the β-CD. The Monte Carlo/Molecular Dynamics (MC/MD) calculations strongly affirmed the adsorption of BM and β-CD-BM over the substrate.

Electrospun Polymer-Free Nanofibers Incorporating Hydroxypropyl-β-cyclodextrin/Difenoconazole via Supramolecular Assembly for Antifungal Activity

In this study, flexible and self-standing hydroxypropyl-β-cyclodextrin/difenoconazole inclusion complex (HPβCD/DZ-IC) nanofibers were prepared by polymer-free electrospinning, which exhibited potential to be a new fast-dissolving pesticide formulation. Scanning electron microscopy and optical microscopy were applied to evaluate the morphology of nanofibers, which showed that the resulting HPβCD/DZ-IC nanofibers were bead-free and uniform. In addition, the proton nuclear magnetic resonance (¹H NMR) spectrum suggested a stoichiometric ratio of 1:0.9 (HPβCD/DZ). Other characterization methods, such as UV-vis absorption, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA), were applied in this study. On the one hand, UV-vis absorption, fluorescence spectroscopy, FT-IR, XRD, and TGA provided useful information for the successful formation of an inclusion complex; on the other hand, the results of TGA indicated the thermal stability of DZ was enhanced after the formation of inclusion complexes. Besides, the phase solubility test could explain the increased water solubility of the nanofibers of inclusion complexes formed by DZ and HPβCD. The results of molecular docking studies demonstrated the most favorable binding interactions when HPβCD combined with DZ. The dissolution test and the antifungal performance test exhibited the characteristics of fast dissolution and the excellent antifungal performance of HPβCD/DZ-IC nanofibers, respectively.

Multifunctional nanocomposite eye drops of cyclodextrin complex@layered double hydroxides for relay drug delivery to the posterior segment of the eye

Topical drug delivery system to the posterior segment of the eye is facing many challenges, such as rapid drug elimination, low permeability, and low concentration at the targeted sites. To overcome these challenges, Multifunctional nanocomposite eye drops of dexamethasone-carboxymethyl-β-cyclodextrin@layered double hydroxides-glycylsarcosine (DEX-CM-β-CD@LDH-GS) were developed for relay drug delivery. Herein, our studies demonstrated that DEX-CM-β-CD@LDH-GS could penetrate through human conjunctival epithelial cells with an intact structure and exhibited integrity in the sclera of rabbits' eyes with in vivo fluorescence resonance energy transfer imaging. Consequently, tissue distribution indicated that DEX-CM-β-CD@LDH-GS nanocomposite eye drops could maintain the effective therapeutic concentration of DEX in choroid-retina within 3 h. As a relay drug delivery system, drug-CD@LDH nanocomposites offer an efficient strategy for drug delivery from ocular surface to the posterior segment.