Antioxidant Vitamin E/Cyclodextrin Inclusion Complex Electrospun Nanofibers: Enhanced Water Solubility, Prolonged Shelf Life, and Photostability of Vitamin E

Unveiling cyclodextrin conjugation as multidentate excipients: An exploratory journey across industries

The discovery of branched molecules like dextrin by Schardinger in 1903 marked the inception of cyclodextrin (CD) utilization, catalyzing its journey from laboratory experimentation to widespread commercialization within the pharmaceutical industry. CD, a cyclic oligosaccharide containing glucopyranose units, acts as a versatile guest molecule, forming inclusion complexes (ICs) with various host molecules. Computational studies have become instrumental in elucidating the intricate interactions between β-CD and guest molecules, enabling the prediction of binding energy, forces, affinity, and complex stability. The computational approach has established robust correlations with experimental outcomes, enhancing our understanding of CD-mediated complexation phenomena. This comprehensive review delves into the CD based Inclusion complex (CDIC) formation and a myriad of components, including drug molecules, amino acids, vitamins, and volatile oils. These complexes find applications across diverse industries, ranging from pharmaceuticals to nutraceuticals, food, fragrance, and beyond. In the pharmaceutical realm, β- CDICs offer innovative solutions for enhancing drug solubility, stability, and bioavailability, thus overcoming formulation challenges associated with poorly water-soluble drugs. Furthermore, the versatility of CDs extends beyond pharmaceuticals, with applications in the encapsulation of phytoactive compounds in nutraceuticals and the enhancing flavor, aroma in food and fragrance industries. This review underscores the pivotal role of CDs conjugation in modern drug delivery systems, emphasizing the importance of interdisciplinary approaches that integrate computational modeling with experimental validation. As the pharmaceutical landscape continues to evolve, CDs-based formulations stand poised to drive innovation and address the ever-growing demand for efficacious and patient-friendly drug delivery solutions.

Polymer-Free Electrospinning of β-Cyclodextrin-Oligolactide for Magnolol and Honokiol Pharmaceutical Formulations

Background: Magnolol (MG) and honokiol (HK) are bioactive compounds extracted from Magnolia obovata and Magnolia Officinalis trees with significant pharmacological properties, including antioxidant and antibacterial activity. However, their poor water solubility and low bioavailability limit the therapeutic potential. Methods: To address these limitations, this study aims to develop MG and HK formulations by co-electrospinning using custom-synthesized β-cyclodextrin-oligolactide (β-CDLA) derivatives. MALDI MS and NMR were employed for the structural assessment of the β-CDLA derivatives. This polymer-free electrospinning technique utilizes the high solubility of β-CDLA to incorporate MG and HK into fibrous webs. The morphology of the resulting fibers is established by SEM and further characterized using FTIR and NMR spectroscopy to confirm the successful incorporation of MG and HK. The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, while the antimicrobial activity was evaluated against several standard microorganisms (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans). Results: The MG and HK electrospun formulations were prepared using highly concentrated feed solutions in dimethylformamide (180% w/v). The resulting β-CDLA fibers, with diameters above 400 nm and an active compound content of 7% wt., exhibited enhanced long-term antioxidant activity and improved antimicrobial efficacy, including notable activity against Escherichia coli. Conclusions: This study demonstrates the potential of MG and HK-loaded β-CDLA fibrous formulations as delivery systems with prolonged antioxidant activity and notable antibacterial efficacy, providing a promising platform for biomedical applications.

Improving stabilization of α-tocopherol and α-tocopheryl acetate against oxidation, light and UV radiation by complexation with β-cyclodextrin and starch

Despite the remarkably high antioxidant activity of tocopherols, their applications in the food industry are limited because of their instability under various conditions. Complexes of α-tocopherol (α-TQ) or α-tocopheryl acetate (α-TQA) with β-cyclodextrin (β-CD) or starch were prepared and characterized by UV-vis, IR and thermal analysis. Oxidative stability of α-TQ and α-TQA against H2O2 was 74.7 and 88.8% respectively (576 h). However, stability increased to 82.9 and 100% for β-CD and 99.2 and 99.4% for starch complexes respectively, which indicates that starch is an excellent stabilizing host in addition to being an economic material. Stability of α-TQ and α-TQA under light conditions was dependent on their physical state; it was 55.3 and 82.9% (oil) but stability was lowered to 19.4 and 76.5% in solution (2.21 mM). In addition, exposure to UV irradiation decreased their stability to 39.2 and 85.0% as oil and 61.2 and 89.1% in solution respectively. However, the stability of all complexes remained > 99.0% under light and UV conditions. Accordingly, α-TQ, the natural and biologically active form, can be used as complex rather than α-TQA often used because of its higher stability. Docking revealed that both forms fit in β-CD with the side chain taking "U" conformation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-06011-2.

Cyclodextrins and their potential applications for delivering vitamins, iron, and iodine for improving micronutrient status

Cyclodextrins (CDs) have been investigated as potential biopolymeric carriers that can form inclusion complexes with numerous bioactive ingredients. The inclusion of micronutrients (e.g. vitamins or minerals) into cyclodextrins can enhance their solubility and provide oxidative or thermal stability. It also enables the formulation of products with extended shelf-life. The designed delivery systems with CDs and their inclusion complexes including electrospun nanofibers, emulsions, liposomes, and hydrogels, show potential in enhancing the solubility and oxidative stability of micronutrients while enabling their controlled and sustained release in applications including food packaging, fortified foods and dietary supplements. Nano or micrometer-sized delivery systems capable of controlling burst release and permeation, or moderating skin hydration have been reported, which can facilitate the formulation of several personal and skin care products for topical or transdermal delivery of micronutrients. This review highlights recent developments in the application of CDs for the delivery of micronutrients, i.e. vitamins, iron, and iodine, which play key roles in the human body, emphasizing their existing and potential applications in the food, pharmaceuticals, and cosmeceuticals industries.

Preparation of biocompatible Zein/Gelatin/Chitosan/PVA based nanofibers loaded with vitamin E-TPGS via dual-opposite electrospinning method

Wound management is a critical aspect of healthcare, necessitating effective and innovative wound dressing materials. Many existing wound dressings lack effectiveness and exhibit limitations, including poor antimicrobial activity, toxicity, inadequate moisture regulation, and weak mechanical performance. The aim of this study is to develop a natural-based nanofibrous structure that possesses desirable characteristics for use as a wound dressing. The chemical analysis confirmed the successful creation of Zein (Ze) (25% w/v) /gelatin (Gel) (10% w/v) /chitosan (CS) (2% w/v) /Polyvinyl alcohol (PVA) (10% w/v) nanofibrous scaffolds loaded with vitamin E tocopheryl polyethylene glycol succinate (Vit E). The swelling percentages of nanofiber (NF), NF + Vit E, cross-linked nanofiber (CNF), and CNF + Vit E were 49%, 110%, 410%, and 676%, respectively; and the degradation rates of NF, NF + Vit E, CNF, and CNF + Vit E were 29.57 ± 5.06%, 33.78 ± 7.8%, 14.03 ± 7.52%, 43 ± 6.27%, respectively. The antibacterial properties demonstrated that CNF impregnated with antibiotics reduced Escherichia coli (E. coli) counts by approximately 27-28% and Staphylococcus aureus (S. aureus) counts by about 34-35% compared to negative control. In conclusion, cross-linked Ze/Gel/CS/PVA nanofibrous scaffolds loaded with Vit E have potential as suitable wound dressing materials because environmentally friendly materials contribute to sustainable wound care and controlled degradation ensures wound dressings breakdown harmlessly.

pH-responsive Aminated mesoporous silica microspheres modified with soybean hull polysaccharides for curcumin encapsulation and controlled release

Mesoporous silica microspheres (MSMs) possess poor biocompatibility. This study focuses on integrating MSMs with polymers to obtain hybrid materials with superior performance compared to the individual components and responsive release in specific environments. The synthesized MSMs were aminated, and subsequently, soybean hull polysaccharide (SHPs) was modified onto MSMs-NH2 to produce MSMs-NH2@SHPs nanoparticles. The encapsulation rate, loading rate of curcumin (Cur), and in vitro release behavior were investigated. Results indicated that the encapsulation efficiency of Cur by MSMs-NH2@SHPs nanoparticles reached 75.58%, 6.95 times that of MSMs-NH2 with a load capacity of 35.12%. It is noteworthy that these nanoparticles exhibit pH-responsive release capacity in vitro. The cumulative release rate of the three nanoparticles at pH 5.0 was higher than that at pH 7.4. MSMs-NH2@SHPs had a cumulative release rate of 56.55% at pH 7.4, increasing to 76.21% at pH 5.0. In vitro experiments have shown that MSMs-based nanoparticles have high delivery efficiency and can achieve pH-sensitive drug release, with a high release rate in a slightly acidic acid, highlighting the potential for controlled release of Cur.

Dual encapsulation and sequential release of cisplatin and vitamin E from soy polysaccharides and β-cyclodextrin bioadhesive hydrogel nanoparticles

Chemically cross-linked hydrogel nanoparticles (HGNPs) offer enhanced properties over their physical counterparts, particularly in drug delivery and cell encapsulation. This study applied pH-thermal dual responsive bio-adhesive HGNPs for dual complexation and enhanced the controlled release and bioavailability of cisplatin (CDDP) and Vitamin E (VE) drugs. The CDDP was loaded into the HGNPs via chemical conjugation with the carboxyl groups in the HGNPs surface by soy polysaccharides (SSPS). At the same time, the host-guest interaction complexed the VE through the β-cyclodextrin (β-CD). The HGNPs showed a uniform HGNPs size distribution of 90.77 ± 14.77 nm and 81.425 ± 13.21 nm before and after complexation, respectively. The FTIR, XRD, XPS, and zeta potential confirmed the conjugation. The cumulative release percent of CDDP reached 98 % at pH 1.2, while <45 % was released at pH 7.4. Our HGNPs enhance the incorporation of CDDP by substituting its chlorides with carboxyl groups of the SSPS; the loading of CDDP and VE was 15 ± 0.33 and 11.32 ± 0.25 wt%, respectively. Moreover, the CDDP and VE also released slower from the HGNPs at 25 °C than at 37 °C and 42 °C. The (VE/CDDP)-loaded HGNPs exhibited longer circulation time in vivo than free CDDP and free VE suspension.

Advances and applications of crosslinked electrospun biomacromolecular nanofibers

Electrospinning is a technology for fabricating ultrafine fibers from natural or synthetic polymers that have novel or enhanced functional properties. These fibers have found applications in a diverse range of fields, including the food, medicine, cosmetics, agriculture, and chemical industries. However, the tendency for electrospun nanofibers to dissociate when exposed to certain environmental conditions limits many of their practical applications. The structural integrity and functional attributes of these nanofibers can be improved using physical and/or chemical crosslinking methods. This review article discusses the formation of polymeric nanofibers using electrospinning and then describes how different crosslinking methods can be used to enhance their mechanical, thermal, and biological attributes. Methods for optimizing the crosslinking reactions are discussed, including proper selection of crosslinker type and reaction conditions. Then, food, medical, and separation applications of crosslinked electrospun fibers are assessed, including in bone and skin tissue engineering, wound healing, drug delivery, air filtration, water filtration, oil removal, food packaging, food preservation, and bioactive delivery. Finally, areas where future research are needed are highlighted, as well as possible future applications of crosslinked nanofibers.

Harmony in Motion: Unraveling the Nexus of Sports, Plant-Based Nutrition, and Antioxidants for Peak Performance

The intricate interplay between plant-based nutrition, antioxidants, and their impact on athletic performance forms the cornerstone of this comprehensive review. Emphasizing the pivotal importance of dietary choices in the realm of sports, this paper sets the stage for an in-depth exploration of how stress and physical performance are interconnected through the lens of nutrition. The increasing interest among athletes in plant-based diets presents an opportunity with benefits for health, performance, and recovery. It is essential to investigate the connection between sports, plants, and antioxidants. Highlighting the impact of nutrition on recovery and well-being, this review emphasizes how antioxidants can help mitigate oxidative stress. Furthermore, it discusses the growing popularity of plant-based diets among athletes. It elaborates on the importance of antioxidants in combating radicals addressing stress levels while promoting cellular health. By identifying rich foods, it emphasizes the role of a balanced diet in ensuring sufficient intake of these beneficial compounds. Examining stress within the context of sports activities, this review provides insights into its mechanisms and its impact on athletic performance as well as recovery processes. This study explores the impact of plant-based diets on athletes including their types, potential advantages and challenges. It also addresses the drawbacks of relying on plant-based diets, concerns related to antioxidant supplementation and identifies areas where further research is needed. Furthermore, the review suggests directions for research and potential innovations in sports nutrition. Ultimately it brings together the aspects of sports, plant-based nutrition, and antioxidants to provide a perspective for athletes, researchers and practitioners. By consolidating existing knowledge, it offers insights that can pave the way for advancements in the ever-evolving field of sports nutrition.

Preparation, Characterization, and Antioxidant Activity of L-Ascorbic Acid/HP-β-Cyclodextrin Inclusion Complex-Incorporated Electrospun Nanofibers

L-Ascorbic acid (LAA) is a key vitamin, implicated in a variety of physiological processes in humans. Due to its free radical scavenging activity, it is extensively employed as an excipient in pharmaceutical products and food supplements. However, its application is greatly impeded by poor thermal and aqueous stability. Herein, to improve the stability and inhibit oxidative degradation, we prepared LAA-cyclodextrin inclusion complex-incorporated nanofibers (NFs). The continuous variation method (Job plot) demonstrated that LAA forms inclusions with hydroxypropyl-β-cyclodextrin (HP-β-CD) at a 2:1 molar stoichiometric ratio. The NFs were prepared via the single step electrospinning technique, without using any polymer matrix. The solid-state characterizations of LAA/HP-β-CD-NF via powder x-ray diffractometry (PXRD), Fourier-transform infrared (FT-IR) analysis, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and nuclear magnetic resonance (¹H NMR and 2D-NOESY) spectroscopy, reveal the effective encapsulation of the LAA (guest molecule) inside the HP-β-CD (host) cavity. The SEM micrograph reveals an average fiber diameter of ~339 nm. The outcomes of the thermal investigations demonstrated that encapsulation of LAA within HP-β-CD cavities provides improved thermal stability of LAA (by increasing the thermal degradation temperature). The radical scavenging assay demonstrated the enhanced antioxidant potential of LAA/HP-β-CD-NF, as compared to native LAA. Overall, the study shows that cyclodextrin inclusion complex-incorporated NFs, are an effective approach for improving the limitations associated with LAA, and provide promising avenues in its therapeutic and food applications.

Myricetin Nanofibers Enhanced Water Solubility and Skin Penetration for Increasing Antioxidant and Photoprotective Activities

Excessive exposure to ultraviolet radiation (UV) can induce oxidative stress through the over-production of reactive oxygen species (ROS) on the skin. Myricetin (MYR), a natural flavonoid compound, significantly inhibited UV-induced keratinocyte damage; however, its bioavailability is limited by its poor water solubility and inefficient skin penetration ability, which subsequently influences its biological activity. The purpose of the study was to develop a myricetin nanofibers (MyNF) system of hydroxypropyl-β-cyclodextrin (HPBCD)/polyvinylpyrrolidone K120 (PVP)-loaded with MYR that would enhance the water solubility and skin penetration by changing the physicochemical characteristics of MYR, including reducing the particle size, increasing the specific surface area, and amorphous transformation. The results also revealed that the MyNF can reduce cytotoxicity in HaCaT keratinocytes when compared with MYR; additionally, MyNF had better antioxidant and photoprotective activity than raw MYR for the UVB-induced HaCaT keratinocytes damage model due to the MyNF increased water solubility and permeability. In conclusion, our results demonstrate that MyNF is a safe, photostable, and thermostable topical ingredient of antioxidant nanofibers to enhance the skin penetration of MYR and prevent UVB-induced skin damage.

In Vitro and In Silico Study on the Molecular Encapsulation of α-Tocopherol in a Large-Ring Cyclodextrin

α-tocopherol is the physiologically most active form of vitamin E, with numerous biological activities, such as significant antioxidant activity, anticancer capabilities, and anti-aging properties. However, its low water solubility has limited its potential use in the food, cosmetic, and pharmaceutical industries. One possible strategy for addressing this issue is the use of a supramolecular complex with large-ring cyclodextrins (LR-CDs). In this study, the phase solubility of the CD26/α-tocopherol complex was investigated to assess the possible ratios between host and guest in the solution phase. Next, the host-guest association of the CD26/α-tocopherol complex at different ratios of 1:2, 1:4, 1:6, 2:1, 4:1, and 6:1 was studied by all-atom molecular dynamics (MD) simulations. At 1:2 ratio, two α-tocopherol units interact spontaneously with CD26, forming an inclusion complex, as supported by the experimental data. In the 2:1 ratio, a single α-tocopherol unit was encapsulated by two CD26 molecules. In comparison, increasing the number of α-tocopherol or CD26 molecules above two led to self-aggregation and consequently limited the solubility of α-tocopherol. The computational and experimental results indicate that a 1:2 ratio could be the most suitable stoichiometry to use in the CD26/α-tocopherol complex to improve α-tocopherol solubility and stability in inclusion complex formation.

Electrospun pullulan nanofiber loading zanthoxylum bungeanum essential oil/β-cyclodextrin inclusion complexes for active packaging

In this study, zanthoxylum bungeanum essential oil/β-cyclodextrin inclusion complexes (ZBEO/β-CD-ICs) were first prepared by precipitation method. When the addition of ZBEO was 1 g, the reaction time was 4 h and the reaction temperature was 55 °C, the recovery (73.88%) and loading content (9.53%) reached the highest value. The characterization results showed inclusion complexation changed the crystalline structure, enhanced interaction among molecules and increased the thermal stability. Then, nanofiber films containing ZBEO/β-CD-ICs were prepared by electrospinning. When the total polymer concentration was constant at 20%, with the increase of ZBEO/β-CD-IC content, the diameter of nanofiber and mechanical strength decreased, but the temperature corresponding to the maximum rate of weight loss increased. X-ray diffraction analysis proved that the addition of ZBEO/β-CD-IC increased the crystallinity degree of film. The Fourier transform infrared spectra indicated hydrogen bond interactions among molecules. Releasing behavior of ZBEO indicated that increase of temperature and relative humidity accelerated the releasing speed. Antibacterial and antioxidant activity results demonstrated the increase of ZBEO content enhanced antibacterial and antioxidant efficiency, Z40P10 nanofibers had the maximum antibacterial rate of 62.02% against S. aureus and the maximum antioxidant activity of 60.18%.

Modulation of CD36-mediated lipid accumulation and senescence by vitamin E analogs in monocytes and macrophages

The CD36/FAT scavenger receptor/fatty acids transporter regulates cellular lipid accumulation important for inflammation, atherosclerosis, lipotoxicity, and initiation of cellular senescence. Here we compared the regulatory effects of the vitamin E analogs alpha-tocopherol (αT), alpha-tocopheryl phosphate (αTP), and αTP/βCD (a nanocarrier complex between αTP and β-cyclodextrin [βCD]) and investigated their regulatory effects on lipid accumulation, phagocytosis, and senescence in THP-1 monocytes and macrophages. Both, αTP and αTP/βCD inhibited CD36 surface exposition stronger than αT leading to more pronounced CD36-mediated events such as inhibition of DiI-labeled oxLDL uptake, phagocytosis of fluorescent Staphylococcus aureus bioparticles, and cell proliferation. When compared to βCD, the complex of αTP/βCD extracted cholesterol from cellular membranes with higher efficiency and was associated with the delivery of αTP to the cells. Interestingly, both, αTP and more so αTP/βCD inhibited lysosomal senescence-associated beta-galactosidase (SA-β-gal) activity and increased lysosomal pH, suggesting CD36-mediated uptake into the endo-lysosomal phagocytic compartment. Accordingly, the observed pH increase was more pronounced with αTP/βCD in macrophages whereas no significant increase occurred with αT, alpha-tocopheryl acetate (αTA) or βCD. In contrast to αT and αTA, the αTP molecule is di-anionic at neutral pH, but upon moving into the acidic endo-lysosomal compartment becomes protonated and thus is acting as a base. Moreover, it is expected to be retained in lysosomes since it still carries one negative charge, similar to lysosomotropic drugs. Thus, treatment with αTP or αTP/βCD and/or inhibition of conversion of αTP to αT as it occurs in aged cells may counteract CD36-mediated overlapping inflammatory, senescent, and atherosclerotic events.

A Hyaluronic Acid-Based Formulation with Simultaneous Local Drug Delivery and Antioxidant Ability for Active Viscosupplementation

Hyaluronic acid (HA) and its derivatives are widely used for intra-articular injection to augment compromised viscoelastic properties of damaged synovial fluid. Combining HA-based devices with anti-inflammatory drugs or bioactive principles in order to provide an additional benefit to the viscosupplementation is emerging as a new promising approach to improve the clinical outcome. Here, we aim to design a novel active viscosupplementation agent that can load and release hydrophobic drugs and at the same time possessing antioxidant properties. Optimized ternary systems named HCV based on HA, (2-hydroxypropyl)-β-cyclodextrin (CD), and vitamin E (VE), without being engaged in formal chemical bonding with each other, showed the best viscoelastic and lubrication properties along with antioxidant capabilities, able to solubilize and release DF. The physical-chemical characterization suggested that the HCV system displayed rheological synergism and higher thermal stability because of the presence of VE and its antioxidant activity, and the loading of hydrophobic drugs was improved by the presence of CD and VE. Cell morphology and viability tests on L929 cells exhibited high biocompatibility of the HCV system with higher level expression of anti-inflammatory interleukin-10.

Recent advances in cyclodextrin-based films for food packaging

Cyclodextrins are garnering increasing attention because they offer several benefits. For instance, cyclodextrins can form several complexes and supramolecular structures not only for food packaging but also for applications in other fields of science. In this review, we discussed the physical and chemical properties of cyclodextrins and the mechanism of their inclusion complex formation. The use of cyclodextrins in various types of food packaging is elaborated upon. We also explain the effects of cyclodextrins on the packaging of fruits, vegetables, meat, fish, and processed foods. Furthermore, some feasible suggestions for future applications are provided. In addition to the positive attributes of cyclodextrins, there are some limitations and drawbacks, which are discussed briefly in this review. In summary, this review can serve as a guide for researchers exploring cyclodextrins for the development of various packaging films.

Fabrication of Nanofibers Based on Hydroxypropyl Starch/Polyurethane Loaded with the Biosynthesized Silver Nanoparticles for the Treatment of Pathogenic Microbes in Wounds

Fabrication of electrospun nanofibers based on the blending of modified natural polymer, hydroxyl propyl starch (HPS) as one of the most renewable resources, with synthetic polymers, such as polyurethane (PU) is of great potential for biomedical applications. The as-prepared nanofibers were used as antimicrobial sheets via blending with biosynthesized silver nanoparticles (AgNPs), which were prepared in a safe way with low cost using the extract of Nerium oleander leaves, which acted as a reducing and stabilizing agent as well. The biosynthesized AgNPs were fully characterized by various techniques (UV-vis, TEM, DLS, zeta potential and XRD). The obtained results from UV-vis depicted that the AgNPs appeared at a wavelength equal to 404 nm affirming the preparation of AgNPs when compared with the wavelength of extract (there are no observable peaks). The average particle size of the fabricated AgNPs that mediated with HPS exhibited a very small size (less than 5 nm) with excellent stability (more than -30 mv). In addition, the fabricated nanofibers were also fully characterized and the obtained data proved that the diameter of nanofibers was enlarged with increasing the concentration of AgNPs. Additionally, the findings illustrated that the pore sizes of electrospun sheets were in the range of 75 to 350 nm. The obtained results proved that the presence of HPS displayed a vital role in decreasing the contact angle of PU nanofibers and thus, increased the hydrophilicity of the net nanofibers. It is worthy to mention that the prepared nanofibers incorporated with AgNPs exhibited incredible antimicrobial activity against pathogenic microbes that actually presented in human wounds. Moreover, P. aeruginosa was the most sensitive species to the fabricated nanofibers compared to other tested ones. The minimal inhibitory concentrations (MICs) values of AgNPs-3@NFs against P. aeruginosa, and E. faecalis, were 250 and 500 mg/L within 15 min, respectively.

A silver-catalyzed [3 + 3]-annulation cascade of alkynyl alcohols and α,β-unsaturated ketones for the regioselective assembly of chromanes

An unprecedented Ag(i)-catalyzed [3 + 3]-annulation of alkynyl alcohols (5-hexyn-1-ols) and α,β-unsaturated ketones is reported to construct simple to complex chromanes.

Clarification of the Complexation Behaviour of 2,6-di-O-Methylated β-Cyclodextrin and Vitamin E and Radical Scavenging Ability of the Complex in Aqueous Solution

The precise understanding of the behaviour of vitamin E (α-tocopherol; Toc) complexed with cyclodextrin (CD) additives in aqueous solution is a fundamental issue for further development of their aqua-related biological applications. In this study, the solubilisation and complexation behaviours of Toc with methyl-substituted CD derivatives and the radical scavenging ability of the resulting complexes were precisely investigated in water media. Several problems were encountered upon pre-dissolving Toc in an organic solvent prior to the addition to the water media, such as enhancement of the dispersibility and decrease in the complexation capacity. Additionally, dispersions were obtained in some cases when mixing CD and Toc even in the absence of an organic solvent; therefore, to perform the measurements, a transparent solution was prepared via filtration with a nanopore filter. Consequently, unexpectedly, the addition of certain CD methylated derivatives did not always enhance the solubility of Toc significantly. However, 2,6-di-O-methylated β-CD (2,6-DMCD) formed a water-soluble inclusion complex with Toc, effectively enhancing its solubility. A phase solubility study indicated the formation of 1:2 or 1:3 Toc/CD inclusion complexes, and the interaction of 2,6-DMCD with both the chromanol head and the phytol chain of Toc was revealed by 2D ROESY nuclear magnetic resonance analysis. The interaction between 2,6-DMCD and the chromanol head was also confirmed for a 2,6-DMCD-2,2,5,7,8-pentamethyl-6-chromanol inclusion complex. Additionally, a rapid scavenging effect for molecularly dissolved Toc was demonstrated even in a system comprising a chromanol head directly encapsulated by CD. Hence, this work elucidated the precise complexation and radical scavenging ability of 2,6-DMCD-Toc in an aqueous solution, which paves the way for its biological applications.

Recent developments in polysaccharide-based electrospun nanofibers for environmental applications

Electrospinning has become an inevitable approach to produce nanofibrous structures for diverse environmental applications. Polysaccharides, due to their variety of types, biobased origins, and eco-friendly, and renewable nature are wonderful materials for the said purpose. The present review discusses the electrospinning process, the parameters involved in the formation of electrospun nanofibers in general, and the polysaccharides in specific. The selection of materials to be electrospun depends on the processing conditions and properties deemed desirable for specific applications. Thereby, the conditions to electrospun polysaccharides-based nanofibers have been focused on for possible environmental applications including air filtration, water treatment, antimicrobial treatment, environmental sensing, and so forth. The polysaccharide-based electrospun membranes, for instance, due to their active adsorption sites could find significant potential for contaminants removal from the aqueous systems. The study also gives some recommendations to overcome any shortcomings faced during the electrospinning and environmental applications of polysaccharide-based matrices.

The Involvement of the Oxidative Stress Status in Cancer Pathology: A Double View on the Role of the Antioxidants

Oxygen-free radicals, reactive oxygen species (ROS) or reactive nitrogen species (RNS), are known by their "double-sided" nature in biological systems. The beneficial effects of ROS involve physiological roles as weapons in the arsenal of the immune system (destroying bacteria within phagocytic cells) and role in programmed cell death (apoptosis). On the other hand, the redox imbalance in favor of the prooxidants results in an overproduction of the ROS/RNS leading to oxidative stress. This imbalance can, therefore, be related to oncogenic stimulation. High levels of ROS disrupt cellular processes by nonspecifically attacking proteins, lipids, and DNA. It appears that DNA damage is the key player in cancer initiation and the formation of 8-OH-G, a potential biomarker for carcinogenesis. The harmful effect of ROS is neutralized by an antioxidant protection treatment as they convert ROS into less reactive species. However, contradictory epidemiological results show that supplementation above physiological doses recommended for antioxidants and taken over a long period can lead to harmful effects and even increase the risk of cancer. Thus, we are describing here some of the latest updates on the involvement of oxidative stress in cancer pathology and a double view on the role of the antioxidants in this context and how this could be relevant in the management and pathology of cancer.

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.

Cyclodextrin Monomers and Polymers for Drug Activity Enhancement

Cyclodextrins (CDs) and cyclodextrin (CD)-based polymers are well-known complexing agents. One of their distinctive features is to increase the quantity of a drug in a solution or improve its delivery. However, in certain instances, the activity of the solutions is increased not only due to the increase of the drug dose but also due to the drug complexation. Based on numerous studies reviewed, the drug appeared more active in a complex form. This review aims to summarize the performance of CDs and CD-based polymers as activity enhancers. Accordingly, the review is divided into two parts, i.e., the effect of CDs as active drugs and as enhancers in antimicrobials, antivirals, cardiovascular diseases, cancer, neuroprotective agents, and antioxidants.

Synthesis and Structural Characterization of 1-(E-1-Arylpropenon-3-yl)-3,4,6-tri-O-benzyl-d-glucals and Their Transformation into Pentasubstituted (2R,3S,4R)-Chromanes via Pd-Catalyzed Cross Dehydrogenative Coupling Reaction

We have developed an efficient methodology for the synthesis of (2R,3S,4R)-2-hydroxymethyl-3,4-dihydroxy-6-aryl-7-aroylchromanes in which the chirality at the C-2, C-3, and C-4 positions is being drawn from C-glucopyranosyl aldehyde, which in turn can be efficiently synthesized from d-glucose. Thus, the synthesis starts with the transformation of sugar aldehyde into 1-(E-1-arylpropenon-3-yl)-3,4,6-tri-O-benzyl-d-glucals using Claisen-Schmidt type condensation reaction with different acetophenones and then to 1,2-disubstituted glucals via Pd(II)-catalyzed cross dehydrogenative coupling reaction, which in turn has been efficiently converted into (2R,3S,4R)-chromanes via 6π-electrocyclization and in situ dehydrogenative aromatization.

Electrospun orally disintegrating film formulation of telmisartan

Telmisartan (TEL) is an antihypertensive BCS class II drug with low solubility at physiological pH. However, the solubility of TEL increases with the presence of an alkalizer. Electrospinning is one of the most recent techniques for the solubility enhancement studies. In this study, an electrospun orally disintegrating film (ODF) formulation of TEL was developed with L-arginine and polyvinylpyrrolidone K90 (PVP), and its characterization studies were performed. Preformulation studies were performed to investigate possible incompatibilities in the components of formulation with differential scanning calorimetry (DSC) and Fourier transform infrared spectrometer (FT-IR) analyses. ODFs were characterized in terms of drug content and uniformity, mechanical properties, fiber shape and diameter and in vitro dissolution profile. Smooth nanofibers without any beads were obtained. The dissolution rate of the TEL significantly increased. The chosen formulation had acceptable mechanical properties with much faster dissolution compared to the commercially available product. Developed ODF and marketed product were compared with a dissolution study in phosphate-buffered solution (pH 7.4). ODF and marketed product both reached 100% release in the 45th minute, and ODF results showed that ODF had much faster release than marketed product. In this study, TEL ODF formulation was successfully produced and characterized.

Polymer-free cyclodextrin and natural polymer-cyclodextrin electrospun nanofibers: A comprehensive review on current applications and future perspectives

The present review discusses the use of cyclodextrins and their derivatives to prepare electrospun nanofibers with specific features. Cyclodextrins, owing to their unique capability to form inclusion complexes with hydrophobic and volatile molecules, can indeed facilitate the encapsulation of bioactive compounds in electrospun nanofibers allowing fast-dissolving products for food, biomedical, and pharmaceutical purposes, filtering materials for wastewater and air purification, as well as a variety of other technological applications. Additionally, cyclodextrins can improve the processability of naturally occurring biopolymers helping the fabrication of "green" materials with a strong industrial relevance. Hence, this review provides a comprehensive state-of-the-art of different cyclodextrins-based nanofibers including those made of pure cyclodextrins, of polycyclodextrins, and those made of natural biopolymer functionalized with cyclodextrins. To this end, the advantages and disadvantages of such approaches and their possible applications are investigated along with the current limitations in the exploitation of electrospinning at the industrial level.

Development of Water-Insoluble Vehicle Comprising Natural Cyclodextrin-Vitamin E Complex

Development of a novel antioxidant-delivery vehicle exerting biosafety has been attracting a great deal of interest. In this study, a vehicle comprising a natural composite consisting of vitamin E (α-tocopherol; Toc) and cyclodextrin (CD) additives was developed, directed toward aqua-related biological applications. Not only β-CD, but also γ-CD, tended to form a water-insoluble aggregate with Toc in aqueous media. The aggregated vehicle, in particular the γ-CD-added system, showed a remarkable sustained effect because of slow dynamics. Furthermore, a prominent cytoprotective effect by the γ-CD-Toc vehicle under the oxidative stress condition was confirmed. Thus, the novel vitamin E vehicle motif using γ-CD as a stabilizer was proposed, widening the usability of Toc for biological applications.

Sunscreens Containing Cyclodextrin Inclusion Complexes for Enhanced Efficiency: A Strategy for Skin Cancer Prevention

Unprotected exposure of skin to solar ultraviolet radiation (UVR) may damage the DNA of skin cells and can lead to skin cancer. Sunscreens are topical formulations used to protect skin against UVR. The active ingredients of sunscreens are UV filters that absorb, scatter, and/or reflect UVR. Preventing the formation of free radicals and repairing DNA damages, natural antioxidants are also added to sunscreens as a second fold of protection against UVR. Antioxidants can help stabilise these formulations during the manufacturing process and upon application on skin. However, UV filters and antioxidants are both susceptible to degradation upon exposure to sunlight and oxygen. Additionally, due to their poor water solubility, natural antioxidants are challenging to formulate and exhibit limited penetration and bioavailability in the site of action (i.e., deeper skin layers). Cyclodextrins (CDs) are cyclic oligosaccharides that are capable of forming inclusion complexes with poorly soluble drugs, such as antioxidants. In this review, we discuss the use of CDs inclusion complexes to enhance the aqueous solubility of antioxidants and chemical UV filters and provide a protective shield against degradative factors. The role of CDs in providing a controlled drug release profile from sunscreens is also discussed. Finally, incorporating CDs inclusion complexes into sunscreens has the potential to increase their efficiency and hence improve their skin cancer prevention.

Progress in the design and development of "fast-dissolving" electrospun nanofibers based drug delivery systems - A systematic review

Electrospinning has emerged as most viable approach for the fabrication of nanofibers with several beneficial features that are essential to various applications ranging from environment to biomedicine. The electrospun nanofiber based drug delivery systems have shown tremendous advancements over the controlled and sustained release complemented from their high surface area, tunable porosity, mechanical endurance, offer compatible environment for drug encapsulation, biocompatibility, high drug loading and tailorable release characteristics. The dosage formulation of poorly water-soluble drugs often faces several challenges including complete dissolution with maximum therapeutic efficiency over a short period of time especially through oral administration. In this context, challenges associated with the dosage formulation of poorly-water soluble drugs can be addressed through combining the beneficial features of electrospun nanofibers. This review describes major developments progressed in the preparation of electrospun nanofibers based "fast dissolving" drug delivery systems by employing variety of polymers, drug molecules and encapsulation approaches with primary focus on oral delivery. Furthermore, the review also highlights current scientific challenges and provide an outlook with regard to future prospectus.

Hyaluronic-acid-based β-cyclodextrin grafted copolymers as biocompatible supramolecular hosts to enhance the water solubility of tocopherol

Hyaluronic acid (HA), a common biopolymer found in the extracellular fluid, was grafted with β-cyclodextrin (β-CD) to form a composite polymer that could form inclusion complexes with tocopherol (VE), enhancing its water-solubility and serving as a model drug delivery system. Herein, different copolymers were prepared with varying HA:β-CD ratios and characterized. VE loading capacity was directly correlated with increased β-CD composition in the polymers and morphological changes were observed upon VE binding. The host materials and their VE inclusion complexes are not cytotoxic, and are thus useful for VE and drug delivery.

Encapsulation of Bioactive Compounds from Aloe Vera Agrowastes in Electrospun Poly (Ethylene Oxide) Nanofibers

Aloe Vera is an ancient medicinal plant especially known for its beneficial properties for human health, due to its bioactive compounds. In this study, nanofibers with antioxidant activity were successfully obtained by electrospinning technique with the addition of a natural Aloe Vera skin extract (AVE) (at 0, 5, 10 and 20 wt% loadings) in poly(ethylene oxide) (PEO) solutions. The successful incorporation of AVE into PEO was evidenced by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging (ABTS) and ferric reducing power (FRAP) assays. The incorporation of AVE introduced some changes in the PEO/AVE nanofibers morphology showing bimodal diameter distributions for AVE contents in the range 10-20 wt%. Some decrease in thermal stability with AVE addition, in terms of decomposition onset temperature, was also observed and it was more evident at high loading AVE contents (10 and 20 wt%). High encapsulation efficiencies of 92%, 76% and 105% according to DPPH, FRAP and ABTS assays, respectively, were obtained at 5 wt% AVE content, retaining AVE its antioxidant capacity in the PEO/AVE electrospun nanofibers. The results suggested that the obtained nanofibers could be promising materials for their application in active food packaging to decrease oxidation of packaged food during storage.

Synthesis of Sugar Diene and Its Pd-Catalyzed Transformation into Chromanes

A route to synthesize 1,2-disubstituted glucals has been developed, which were further converted to substituted chromanes by thermal 6π-electrocyclization in HMPA followed by in situ aromatization. One of the key steps in the synthesis of chromane is metal-free generation of C1-substituted glucal from d-mannose, which was further converted to 1,2-disubstituted glucals by Pd-catalyzed Fujiwara-Moritani reaction with styrenes, acrylates, acrylamide, acrylonitrile, and ethyl vinyl ketone in good yields.

Design of polymer-free Vitamin-A acetate/cyclodextrin nanofibrous webs: antioxidant and fast-dissolving properties

Polymer-free inclusion complex nanofibers of Vitamin-A acetate/cyclodextrin were prepared having fast-dissolving and enhanced antioxidant properties for the purpose of new-generation food/dietary supplement systems.