Comparative Evaluation of Solubility, Cytotoxicity and Photostability Studies of Resveratrol and Oxyresveratrol Loaded Nanosponges

Research progress of SIRTs activator resveratrol and its derivatives in autoimmune diseases

Autoimmune diseases (AID) have emerged as prominent contributors to disability and mortality worldwide, characterized by intricate pathogenic mechanisms involving genetic, environmental, and autoimmune factors. In response to this challenge, a growing body of research in recent years has delved into genetic modifications, yielding valuable insights into AID prevention and treatment. Sirtuins (SIRTs) constitute a class of NAD-dependent histone deacetylases that orchestrate deacetylation processes, wielding significant regulatory influence over cellular metabolism, oxidative stress, immune response, apoptosis, and aging through epigenetic modifications. Resveratrol, the pioneering activator of the SIRTs family, and its derivatives have captured global scholarly interest. In the context of AID, these compounds hold promise for therapeutic intervention by modulating the SIRTs pathway, impacting immune cell functionality, suppressing the release of inflammatory mediators, and mitigating tissue damage. This review endeavors to explore the potential of resveratrol and its derivatives in AID treatment, elucidating their mechanisms of action and providing a comprehensive analysis of current research advancements and obstacles. Through a thorough examination of existing literature, our objective is to advocate for the utilization of resveratrol and its derivatives in AID treatment while offering crucial insights for the formulation of innovative therapeutic approaches.

Evaluating solubility, stability, and inclusion complexation of oxyresveratrol with various β-cyclodextrin derivatives using advanced computational techniques and experimental validation

Oxyresveratrol (OXY), a natural stilbenoid in mulberry fruits, is known for its diverse pharmacological properties. However, its clinical use is hindered by low water solubility and limited bioavailability. In the present study, the inclusion complexes of OXY with β-cyclodextrin (βCD) and its three analogs, dimethyl-β-cyclodextrin (DMβCD), hydroxypropyl-β-cyclodextrin (HPβCD) and sulfobutylether-β-cyclodextrin (SBEβCD), were investigated using in silico and in vitro studies. Molecular docking revealed two binding orientations of OXY, namely, 4',6'-dihydroxyphenyl (A-form) and 5,7-benzenediol ring (B-form). Molecular Dynamics simulations suggested the formation of inclusion complexes with βCDs through two distinct orientations, with OXY/SBEβCD exhibiting maximum atom contacts and the lowest solvent-exposed area in the hydrophobic cavity. These results corresponded well with the highest binding affinity observed in OXY/SBEβCD when assessed using the MM/GBSA method. Beyond traditional simulation methods, Ligand-binding Parallel Cascade Selection Molecular Dynamics method was employed to investigate how the drug enters and accommodates within the hydrophobic cavity. The in silico results aligned with stability constants: SBEβCD (2060 M-1), HPβCD (1860 M-1), DMβCD (1700 M-1), and βCD (1420 M-1). All complexes exhibited a 1:1 binding mode (AL type), with SBEβCD enhancing OXY solubility (25-fold). SEM micrographs, DSC thermograms, FT-IR and 1H NMR spectra confirm the inclusion complex formation, revealing novel surface morphologies, distinctive thermal behaviors, and new peaks. Notably, the inhibitory impact on the proliferation of breast cancer cell lines, MCF-7, exhibited by inclusion complexes particularly OXY/DMβCD, OXY/HPβCD, and OXY/SBEβCD were markedly superior compared to that of OXY alone.

Advancements in application of chitosan and cyclodextrins in biomedicine and pharmaceutics: recent progress and future trends

The global community is faced with numerous health concerns such as cancer, cardiovascular and neurological diseases, diabetes, joint pain, osteoporosis, among others. With the advancement of research in the fields of materials chemistry and medicine, pharmaceutical technology and biomedical analysis have entered a new stage of development. The utilization of natural oligosaccharides and polysaccharides in pharmaceutical/biomedical studies has gained significant attention. Over the past decade, several studies have shown that chitosan and cyclodextrin have promising biomedical implications in background analysis, ongoing development, and critical applications in biomedical and pharmaceutical research fields. This review introduces different types of saccharides/natural biopolymers such as chitosan and cyclodextrin and discusses their wide-ranging applications in the biomedical/pharmaceutical research area. Recent research advances in pharmaceutics and drug delivery based on cyclodextrin, and their response to smart stimuli, as well as the biological functions of cyclodextrin and chitosan, such as the immunomodulatory effects, antioxidant, and antibacterial properties, have also been discussed, along with their applications in tissue engineering, wound dressing, and drug delivery systems. Finally, the innovative applications of chitosan and cyclodextrin in the pharmaceutical/biomedicine were reviewed, and current challenges, research/technological gaps, and future development opportunities were surveyed.

Comprehensive Insights into Ochratoxin A: Occurrence, Analysis, and Control Strategies

Ochratoxin A (OTA) is a toxic mycotoxin produced by some mold species from genera Penicillium and Aspergillus. OTA has been detected in cereals, cereal-derived products, dried fruits, wine, grape juice, beer, tea, coffee, cocoa, nuts, spices, licorice, processed meat, cheese, and other foods. OTA can induce a wide range of health effects attributable to its toxicological properties, including teratogenicity, immunotoxicity, carcinogenicity, genotoxicity, neurotoxicity, and hepatotoxicity. OTA is not only toxic to humans but also harmful to livestock like cows, goats, and poultry. This is why the European Union and various countries regulate the maximum permitted levels of OTA in foods. This review intends to summarize all the main aspects concerning OTA, starting from the chemical structure and fungi that produce it, its presence in food, its toxicity, and methods of analysis, as well as control strategies, including both fungal development and methods of inactivation of the molecule. Finally, the review provides some ideas for future approaches aimed at reducing the OTA levels in foods.

Hierarchically Templated Synthesis of 3D-Printed Crosslinked Cyclodextrins for Lycopene Harvesting

Plants produce a wide range of bioactive phytochemicals, such as antioxidants and vitamins, which play crucial roles in aging prevention, inflammation reduction, and reducing the risk of cancer. Selectively harvesting these phytochemicals, such as lycopene, from tomatoes through the adsorption method is cost-effective and energy efficient. In this work, a templated synthesis of 3D-printed crosslinked cyclodextrin polymers featuring nanotubular structures for highly selective lycopene harvesting is reported. Polypseudorotaxanes formed by triethoxysilane-based telechelic polyethylene glycols and α-cyclodextrins (α-CDs) are designed as the template to (1) synthetically access urethane-based nanotubular structures at the molecular level, and (2) construct 3D-printed architectures with designed macroscale voids. The polypseudorotaxane hydrogels showed good rheological properties for direct ink writing, and the 3D-printed hydrogels were converted to the desired α-CD polymer network through a three-step postprinting transformation. The obtained urethane-crosslinked α-CD monoliths possess nanotubular structures and 3D-printed voids. They selectively adsorb lycopene from raw tomato juice, protecting lycopene from photo- or thermo-degradations. This work highlights the hierarchically templated synthesis approach in developing functional 3D-printing materials by connecting the bottom-up molecular assembly and synthesis with the top-down 3D architecture control and fabrication.

Resveratrol-Laden Nano-Systems in the Cancer Environment: Views and Reviews

The genesis of cancer is a precisely organized process in which normal cells undergo genetic alterations that cause the cells to multiply abnormally, colonize, and metastasize to other organs such as the liver, lungs, colon, and brain. Potential drugs that could modify these carcinogenic pathways are the ones that will be used in clinical trials as anti-cancer drugs. Resveratrol (RES) is a polyphenolic natural antitoxin that has been utilized for the treatment of several diseases, owing to its ability to scavenge free radicals, control the expression and activity of antioxidant enzymes, and have effects on inflammation, cancer, aging, diabetes, and cardioprotection. Although RES has a variety of pharmacological uses and shows promising applications in natural medicine, its unpredictable pharmacokinetics compromise its therapeutic efficacy and prevent its use in clinical settings. RES has been encapsulated into various nanocarriers, such as liposomes, polymeric nanoparticles, lipidic nanocarriers, and inorganic nanoparticles, to address these issues. These nanocarriers can modulate drug release, increase bioavailability, and reach therapeutically relevant plasma concentrations. Studies on resveratrol-rich nano-formulations in various cancer types are compiled in the current article. Studies relating to enhanced drug stability, increased therapeutic potential in terms of pharmacokinetics and pharmacodynamics, and reduced toxicity to cells and tissues are the main topics of this research. To keep the readers informed about the current state of resveratrol nano-formulations from an industrial perspective, some recent and significant patent literature has also been provided. Here, the prospects for nano-formulations are briefly discussed, along with machine learning and pharmacometrics methods for resolving resveratrol's pharmacokinetic concerns.

Oxygen Nanocarriers for Improving Cardioplegic Solution Performance: Physico-Chemical Characterization

Nanocarriers for oxygen delivery have been the focus of extensive research to ameliorate the therapeutic effects of current anti-cancer treatments and in the organ transplant field. In the latter application, the use of oxygenated cardioplegic solution (CS) during cardiac arrest is certainly beneficial, and fully oxygenated crystalloid solutions may be excellent means of myocardial protection, albeit for a limited time. Therefore, to overcome this drawback, oxygenated nanosponges (NSs) that can store and slowly release oxygen over a controlled period have been chosen as nanocarriers to enhance the functionality of cardioplegic solutions. Different components can be used to prepare nanocarrier formulations for saturated oxygen delivery, and these include native α-cyclodextrin (αCD), αcyclodextrin-based nanosponges (αCD-NSs), native cyclic nigerosyl-nigerose (CNN), and cyclic nigerosyl-nigerose-based nanosponges (CNN-NSs). Oxygen release kinetics varied depending on the nanocarrier used, demonstrating higher oxygen release after 24 h for NSs than the native αCD and CNN. CNN-NSs presented the highest oxygen concentration (8.57 mg/L) in the National Institutes of Health (NIH) CS recorded at 37 °C for 12 h. The NSs retained more oxygen at 1.30 g/L than 0.13 g/L. These nanocarriers have considerable versatility and the ability to store oxygen and prolong the amount of time that the heart remains in hypothermic CS. The physicochemical characterization presents a promising oxygen-carrier formulation that can prolong the release of oxygen at low temperatures. This can make the nanocarriers suitable for the storage of hearts during the explant and transport procedure.

Oxyresveratrol Attenuates Inflammation in Human Keratinocyte via Regulating NF-kB Signaling and Ameliorates Eczematous Lesion in DNCB-Induced Dermatitis Mice

Oxyresveratrol (ORV) is one of the novel antioxidants having been extensively studied in recent years. One of the main sources of ORV is Artocarpus lakoocha, which has been used in traditional medicine in Thailand for decades. However, the role of ORV in skin inflammation has not been clearly demonstrated. Therefore, we investigated the anti-inflammatory effects of ORV on dermatitis model. The effect of ORV was examined on human immortalized and primary skin cells exposed to bacterial components including peptidoglycan (PGN) and lipopolysaccharide (LPS) and 2,4-Dinitrochlorobenzene (DNCB)-induced dermatitis mouse model. PGN and LPS were used to induce inflammation on immortalized keratinocytes (HaCaT) and human epidermal keratinocytes (HEKa). We then performed MTT assay, Annexin V and PI assay, cell cycle analysis, real-time PCR, ELISA and Western blot in these in vitro models. H&E staining, immunohistochemistry (IHC) staining with CD3, CD4 and CD8 markers were used to evaluate the effects of ORV in in vivo model of skin inflammation using BALB/c mice. Pretreatment of HaCaT and HEKa cells with ORV inhibited pro-inflammatory cytokine production through inhibition of NF-κB pathway. In DNCB-induced dermatitis mouse model, ORV treatment reduced lesion severity, and skin thickness and numbers of CD3, CD4 and CD8 T cells in the sensitized skin of mice. In conclusion, it has been demonstrated that ORV treatment can ameliorate inflammation in the in vitro models of skin inflammation and in vivo models of dermatitis, suggesting a therapeutic potential of ORV for treatment of skin diseases particularly eczema.

Non-ionic surfactant-assisted controlled release of oxyresveratrol on dendritic fibrous silica for topical applications

We present a simple and eco-friendly method for controlled drug release using a surfactant-assisted method. Oxyresveratrol (ORES) was co-loaded with a non-ionic surfactant onto KCC-1, a dendritic fibrous silica, using an ethanol evaporation technique. The carriers were characterized using FE-SEM, TEM, XRD, N₂ adsorption-desorption, FTIR, and Raman spectroscopy, and the loading and encapsulation efficiencies were assessed using TGA and DSC techniques. Contact angle and zeta potential were used to determine the surfactant arrangement and the particle charges. To investigate the effects of different surfactants (Tween 20, Tween 40, Tween 80, Tween 85, and Span 80) on ORES release, we conducted experiments under different pH and temperature conditions. Results showed that the types of surfactants, drug loading content, pH, and temperature significantly affected the drug release profile. The percentage of drug loading efficiency of the carriers was in the range of 80 %-100 %, and the release of ORES was in the order of M/KCC-1 > M/K/S80 > M/K/T40 > M/K/T20 > MK/T80 > M/K/T85 at 24 h. Furthermore, the carriers provided excellent protection for ORES against UVA and maintained its antioxidant activity. KCC-1 and Span 80 enhanced the cytotoxicity to HaCaT cells, while Tween 80 suppressed the cytotoxicity.

Comparative evaluation of dithranol-loaded nanosponges fabricated by solvent evaporation technique and melt method

Background

Dithranol, a standard drug for psoriasis, has lured keen attention by virtue of its antioxidant, anti-proliferative and anti-inflammatory activities. However, its poor stability and solubility critically impair the formulation design, evaluation and administration. To improve these issues, dithranol was encased in β-cyclodextrin nanosponges using solvent evaporation technique. Previously, nanosponges containing dithranol were developed in our laboratory using melt technique. Herein, a comparison of nanosponges prepared by both techniques was also included.

Results

Different nanosponge batches were engineered using diphenyl carbonate as cross-linker with β-cyclodextrin as polymer employing solvent evaporation technique. Dithranol was loaded in nanosponges via lyophilization. Fourier transform infrared spectroscopy, differential scanning colorimeter and powdered X-ray diffraction studies confirmed successful encapsulation and complexation of this drug in β-cyclodextrin nanosponges. The effect of a variable amount of cross-linker on the solubility, encapsulation efficiency, zeta potential, particle size and polydispersity index was evaluated in fabricated nanocarriers. Further, β-cyclodextrin nanosponge batches were subjected to solubility studies, photostability examination and antioxidant activity analysis and compared with previously prepared dithranol-loaded nanosponges. From the present studies results, it was concluded that dithranol-loaded nanosponges using solvent evaporation technique not only improved solubility and photostability but also preserved the antioxidant efficacy of the chosen drug.

Conclusion

The overall results emphasized moral guidance concerning encapsulation, evaluation and characterization and accredited dithranol solubilization, photostability and antioxidant potential. However, solvent evaporation and melt method are easy and promising methods to fabricate nanosponges for dithranol. This comparative study demonstrated the parameters which were affected by chosen techniques. Further, from the results of present studies, it was concluded that the formulation scientists should select the preparation technique based on the objective of their research work and requirement of desired features.

Graphical abstract

Resveratrol and Its Role in the Management of B-Cell Malignancies-A Recent Update

The growing incidence of B cell malignancies globally has prompted research on the pharmacological properties of phytoconstituents in cancer management. Resveratrol, a polyphenolic stilbenoid widely found in nature, has been explored for its anti-inflammatory and antioxidant properties, and promising results from different pre-clinical studies have indicated its potential for management of B cell malignancies. However, these claims must be substantiated by a greater number of clinical trials in diverse populations, in order to establish its safety and efficacy profile. In addition to this, there is a need to explore nanodelivery of this agent, owing to its poor solubility, which in turn may impact its bioavailability. This review aims to offer an overview of the occurrence and pathogenesis of B cell malignancies with a special focus on the inflammatory pathways involved, the mechanism of actions of resveratrol and its pharmacokinetic profile, results from pre-clinical and clinical studies, as well as an overview of the marketed formulations. The authors have also presented their opinion on the various challenges associated with the clinical development of resveratrol and future perspectives regarding therapeutic applications of this agent.

β-Cyclodextrin-Based Nanosponges Inclusion Compounds Associated with Gold Nanorods for Potential NIR-II Drug Delivery

This article describes the synthesis and characterization of two nanocarriers consisting of β-cyclodextrin-based nanosponges (NSs) inclusion compounds (ICs) and gold nanorods (AuNRs) for potential near-infrared II (NIR-II) drug-delivery systems. These nanosystems sought to improve the stability of two drugs, namely melphalan (MPH) and curcumin (CUR), and to trigger their photothermal release after a laser irradiation stimulus (1064 nm). The inclusion of MPH and CUR inside each NS was confirmed by field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, Fourier transform infrared spectroscopy, (FT-IR) differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and proton nuclear magnetic resonance (1H-NMR). Furthermore, the association of AuNRs with both ICs was confirmed by FE-SEM, energy-dispersive spectroscopy (EDS), TEM, dynamic light scattering (DLS), ζ-potential, and UV–Vis. Moreover, the irradiation assays demonstrated the feasibility of the controlled-photothermal drug release of both MPH and CUR in the second biological window (1000–1300 nm). Finally, MTS assays depicted that the inclusion of MPH and CUR inside the cavities of NSs reduces the effects on mitochondrial activity, as compared to that observed in the free drugs. Overall, these results suggest the use of NSs associated with AuNRs as a potential technology of controlled drug delivery in tumor therapy, since they are efficient and non-toxic materials.

Dextrin-Based Nanohydrogels for Rokitamycin Prolonged Topical Delivery

Macrolides are widely used antibiotics with a broad spectrum of activity. The development of drug carriers to deliver this type of antibiotics has attracted much research. The present study aims at developing new swellable dextrin-based nanohydrogels for the topical delivery of rokitamycin, as model macrolide. Rokitamycin is a synthetic analogous of macrolides with advantageous characteristics as far as bacterial uptake and post-antibiotic effect are concerned. It is also indicated for the treatment of severe infections caused by Acanthamoeba and for topical infections. The nanohydrogels have been prepared from two types of cross-linked polymers obtained by using β-cyclodextrin or Linecaps^® was provided by the Roquette Italia SPA (Cassano Spinola, Al, Italy) as building blocks. The cross-linked polymers have been then formulated into aqueous nanosuspensions refined and tuned to achieve the incorporation of the drug. Cross-linked β-cyclodextrin (β-CD) and Linecaps^® (LC) polymers formed dextrin-based nanohydrogels with high swelling degree and mucoadhesion capability. Rokitamycin was loaded into the nanohydrogels displaying an average size around 200 nm with negative surface charge. In vitro kinetic profiles of free and loaded drug in nanohydrogels were compared at two pH levels. Interestingly, a sustained and controlled release was obtained at skin pH level due to the high degree of swelling and a pH responsiveness possibly. The results collected suggest that these nanohydrogels are promising for the delivery of rokitamycin and may pave the way for the topical delivery of other macrolide antibiotics.

Lipid-Coated Nanocrystals as a Tool for Improving the Antioxidant Activity of Resveratrol

Trans-resveratrol, a polyphenolic phytoalexin found in various plant sources, has been the focus of increasing attention in recent years because of its role in the prevention of many human diseases, and particularly because of its antioxidant properties. However, the in vivo effect of trans-resveratrol after oral administration is negligible when compared to its efficacy in vitro, due to its low bioavailability. Moreover, it presents stability issues as it is an extremely photosensitive compound when exposed to light. This work aims to develop lipid-coated nanocrystals in order to improve the antioxidant activity and bioavailability of trans-resveratrol. Lipid-coated trans-resveratrol nanocrystals with sizes lower than 500 nm, spherical shapes and smooth surfaces were obtained via a milling method. They showed a faster dissolution rate than the coarse trans-resveratrol powder. The antioxidant properties of trans-resveratrol were not impaired by the milling process. The in vivo pharmacokinetics of lipid-coated trans-resveratrol nanocrystals were evaluated after oral administration to rats, with a commercial Phytosome^® formulation being used for comparison purposes. An increase in the trans-resveratrol area under the curve was observed and the lipid-coated nanocrystal formulation led to an enhancement in the oral bioavailability of the compound.

Developing Novel Hydroxypropyl-β-Cyclodextrin-Based Nanosponges as Carriers for Anticancer Hydrophobic Agents: Overcoming Limitations of Host–Guest Complexes in a Comparative Evaluation

This study aimed to design and fabricate novel hydroxypropyl-β-cyclodextrin-based hypercrosslinked polymers, called nanosponges, as carriers for anticancer hydrophobic agents and compare them with host–guest complexes of hydroxypropyl-β-cyclodextrin, a remarkable solubilizer, to investigate their application in improving the pharmaceutical properties of the flavonoid naringenin, a model hydrophobic nutraceutical with versatile anticancer effects. For this purpose, three new nanosponges, crosslinked with pyromellitic dianhydride, citric acid, and carbonyldiimidazole, were fabricated. The carbonate nanosponge synthesized by carbonyldiimidazole presented the highest naringenin loading capacity (≈19.42%) and exerted significantly higher antiproliferative effects against MCF-7 cancer cells compared to free naringenin. Additionally, this carbonate nanosponge formed a stable nanosuspension, providing several advantages over the naringenin/hydroxypropyl-β-cyclodextrin host–guest complex, including an increase of about 3.62-fold in the loading capacity percentage, sustained released pattern (versus the burst pattern of host–guest complex), and up to an 8.3-fold increase in antiproliferative effects against MCF-7 cancer cells. Both naringenin-loaded carriers were less toxic to L929 murine fibroblast normal cells than MCF-7 cancer cells. These findings suggest that hydroxypropyl-β-cyclodextrin-based carbonate nanosponges could be a good candidate as a drug delivery system with potential applications in cancer treatment.

Nutraceutical Concepts and Dextrin-Based Delivery Systems

Nutraceuticals are bioactive or chemical compounds acclaimed for their valuable biological activities and health-promoting effects. The global community is faced with many health concerns such as cancers, cardiovascular and neurodegenerative diseases, diabetes, arthritis, osteoporosis, etc. The effect of nutraceuticals is similar to pharmaceuticals, even though the term nutraceutical has no regulatory definition. The usage of nutraceuticals, to prevent and treat the aforementioned diseases, is limited by several features such as poor water solubility, low bioavailability, low stability, low permeability, low efficacy, etc. These downsides can be overcome by the application of the field of nanotechnology manipulating the properties and structures of materials at the nanometer scale. In this review, the linear and cyclic dextrin, formed during the enzymatic degradation of starch, are highlighted as highly promising nanomaterials- based drug delivery systems. The modified cyclic dextrin, cyclodextrin (CD)-based nanosponges (NSs), are well-known delivery systems of several nutraceuticals such as quercetin, curcumin, resveratrol, thyme essential oil, melatonin, and appear as a more advanced drug delivery system than modified linear dextrin. CD-based NSs prolong and control the nutraceuticals release, and display higher biocompatibility, stability, and solubility of poorly water-soluble nutraceuticals than the CD-inclusion complexes, or uncomplexed nutraceuticals. In addition, the well-explored CD-based NSs pathways, as drug delivery systems, are described. Although important progress is made in drug delivery, all the findings will serve as a source for the use of CD-based nanosystems for nutraceutical delivery. To sum up, our review introduces the extensive literature about the nutraceutical concepts, synthesis, characterization, and applications of the CD-based nano delivery systems that will further contribute to the nutraceutical delivery with more potent nanosystems based on linear dextrins.

Effect of Natural Deep Eutectic Solvents on trans-Resveratrol Photo-Chemical Induced Isomerization and 2,4,6-Trihydroxyphenanthrene Electro-Cyclic Formation

trans-Resveratrol is a natural bioactive compound with well-recognized health promoting effects. When exposed to UV light, this compound can undergo a photochemically induced trans/cis isomerization and a 6π electrochemical cyclization with the subsequent formation of 2,4,6-trihydroxyphenanthrene (THP). THP is a potentially harmful compound which can exert genotoxic effects. In this work we improved the chromatographic separation and determination of the two resveratrol isomers and of THP by using a non-commercial pentafluorophenyl stationary phase. We assessed the effect of natural deep eutectic solvents (NaDES) as possible photo-protective agents by evaluating cis-resveratrol isomer and THP formation under different UV-light exposure conditions with the aim of enhancing resveratrol photostability and inhibiting THP production. Our results demonstrate a marked photoprotective effect exerted by glycerol-containing NaDES, and in particular by proline/glycerol NaDES, which exerts a strong inhibitory effect on the photochemical isomerization of resveratrol and significantly limits the formation of the toxic derivative THP. Considering the presence of resveratrol in various commercial products, these results are of note in view of the potential genotoxic risk associated with its photochemical degradation products and in view of the need for the development of green, eco-sustainable and biocompatible resveratrol photo-stable formulations.

Cyclodextrin-Based Nanosponges as Perse Antimicrobial Agents Increase the Activity of Natural Antimicrobial Peptide Nisin

At present, antibiotic resistance is considered a real problem. Therefore, for decades scientists have been looking for novel strategies to treat bacterial infections. Nisin Z, an antimicrobial peptide (AMP), can be considered an option, but its usage is mainly limited by the poor stability and short duration of its antimicrobial activity. In this context, cyclodextrin (CD)-based nanosponges (NSs), synthesized using carbonyldiimidazole (CDI) and pyromellitic dianhydride (PMDA), were chosen for nisin Z loading. To determine the minimum inhibitory of nisin Z loaded on CD-NS formulations, agar well diffusion plates were used. Then, the bactericide concentrations of nisin Z loaded on CD-NS formulations were determined against Gram-positive (Staphylococcus aureus) and -negative (Escherichia coli) bacteria, using microdilution brain heart infusion (BHI) and tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). The minimum and bactericide inhibitory values of the nisin complex with NSs were potentially decreased against both bacteria, compared with the nisin-free sample, while the nisin complex with β-CD showed lower antibacterial activity. The antimicrobial effect was also demonstrated by free NSs. Furthermore, the total viable counts (TVCs) antibacterial experiment indicated that the combination of nisin Z in both PMDA and CDI β-CD-based NSs, especially CDI, can provide a better conservative effect on cooked chicken meat. Generally, the present study outcomes suggest that the cross-linked β-CD-based NSs can present their own antimicrobial potency or serve as promising carriers to deliver and enhance the antibacterial action of nisin Z.

Stilbenes: Characterization, bioactivity, encapsulation and structural modifications. A review of their current limitations and promising approaches

Stilbenes are phenolic compounds naturally synthesized as secondary metabolites by the shikimate pathway in plants. Research on them has increased in recent years due to their therapeutic potential as antioxidant, antimicrobial, anti-inflammatory, anticancer, cardioprotective and anti-obesity agents. Amongst them, resveratrol has attracted the most attention, although there are other natural and synthesized stilbenes with enhanced properties. However, stilbenes have some physicochemical and pharmacokinetic problems that need to be overcome before considering their applications. Human clinical evidence of their bioactivity is still controversial due to this fact and hence, exhaustive basis science on stilbenes is needed before applied science. This review gathers the main physicochemical and biological properties of natural stilbenes, establishes structure-activity relationships among them, emphasizing the current problems that limit their applications and presenting some promising approaches to overcome these issues: the encapsulation in different agents and the structural modification to obtain novel stilbenes with better features. The bioactivity of stilbenes should move from promising to evident.

Stabilization and Anticancer Enhancing Activity of the Peptide Nisin by Cyclodextrin-Based Nanosponges against Colon and Breast Cancer Cells

The great variability of cancer types demands novel drugs with broad spectrum, this is the case of Nisin, a polycyclic antibacterial peptide that recently has been considered for prevention of cancer cells growth. As an accepted food additive, this drug would be very useful for intestinal cancers, but the peptide nature would make easier its degradation by digestion procedures. For that reason, the aim of present study to investigate the protective effect of two different β-cyclodextrin-based nanosponges (carbonyl diimidazole and pyromellitic dianhydride) and their anti-cancer enhancement effect of Nisin-Z encapsulated with against colon cancer cells (HT-29). To extend its possible use, a comparison with breast (MCF-7) cancer cell was carried out. The physicochemical properties, loading efficiency, and release kinetics of Nisin complex with nanosponges were studied. Then, tricin-SDS-PAGE electrophoresis was used to understand the effect of NSs on stability of Nisin-Z in the presence of gastric peptidase pepsin. In addition, the cytotoxicity and cell membrane damage of Nisin Z were evaluated by using the MTT and LDH assay, which was complemented via Annexin-V/ Propidium Iodide (PI) by using flowcytometry. CD-NS are able to complex Nisin-Z with an encapsulation efficiency around 90%. A protective effect of Nisin-Z complexed with CD-NSs was observed in presence of pepsin. An increase in the percentage of apoptotic cells was observed when the cancer cells were exposed to Nisin Z complexed with nanosponges. Interestingly, Nisin Z free and loaded on PMDA/CDI-NSs is more selectively toxic towards HT-29 cells than MCF-7 cancer cells. These results indicated that nanosponges might be good candidates to protect peptides and deliver drugs against intestinal cancers.

Resveratrol and Immune Cells: A Link to Improve Human Health

The use of polyphenols as adjuvants in lowering risk factors for various debilitating diseases has been investigated in recent years due to their possible antioxidant action. Polyphenols represent a fascinating and relatively new subject of research in nutraceuticals and nutrition, with interest rapidly expanding since they can help maintain health by controlling metabolism, weight, chronic diseases, and cell proliferation. Resveratrol is a phenolic compound found mostly in the pulp, peels, seeds, and stems of red grapes. It has a wide variety of biological actions that can be used to prevent the beginning of various diseases or manage their symptoms. Resveratrol can influence multiple inflammatory and non-inflammatory responses, protecting organs and tissues, thanks to its interaction with immune cells and its activity on SIRT1. This compound has anti-inflammatory, antioxidant, anti-apoptotic, neuroprotective, cardioprotective, anticancer, and antiviral properties, making it a potential adjunct to traditional pharmaceutical therapy in public health. This review aims to provide a comprehensive analysis of resveratrol in terms of active biological effects and mechanism of action in modifying the immune cellular response to promote human psychophysical health.

Advances and Classification of Cyclodextrin-Based Polymers for Food-Related Issues

Cyclodextrins (CDs) are a good alternative to reduce or enhance different biomolecule characteristics and have demonstrated great results in food science. However, CDs present intrinsic limitations that can be solved by derivative synthesis. This review represents a survey of the state of the art of CD-based materials and their uses in food science. A deep review of the structure is carried out and different groups for ordination are suggested. After that, different applications such as cholesterol complexation or its use as sensors are reviewed. The derivatives show novel and promising activities for the industry. A critical perspective of the materials suggests that they might not present toxicity, although more studies are required. These points suggest that the research in this field will be increased in the following years.

Resveratrol and cyclodextrins, an easy alliance: Applications in nanomedicine, green chemistry and biotechnology

Most drugs or the natural substances reputed to display some biological activity are hydrophobic molecules that demonstrate low bioavailability regardless of their mode of absorption. Resveratrol and its derivatives belong to the chemical group of stilbenes; while stilbenes are known to possess very interesting properties, these are limited by their poor aqueous solubility as well as low bioavailability in animals and humans. Among the substances capable of forming nanomolecular inclusion complexes which can be used for drug delivery, cyclodextrins show spectacular physicochemical and biomedical implications in stilbene chemistry for their possible application in nanomedicine. By virtue of their properties, cyclodextrins have also demonstrated their possible use in green chemistry for the synthesis of stilbene glucosylated derivatives with potential applications in dermatology and cosmetics. Compared to chemical synthesis and genetically modified microorganisms, plant cell or tissue systems provide excellent models for obtaining stilbenes in few g/L quantities, making feasible the production of these compounds at a large scale. However, the biosynthesis of stilbenes is only possible in the presence of the so-called elicitor compounds, the most commonly used of which are cyclodextrins. We also report here on the induction of resveratrol production by cyclodextrins or combinatory elicitation with methyljasmonate in plant cell systems as well as the mechanisms by which they are able to trigger a stilbene response. The present article therefore discusses the role of cyclodextrins in stilbene chemistry both at the physico-chemical level as well as the biomedical and biotechnological levels, emphasizing the notion of "easy alliance" between these compounds and stilbenes.

Resveratrol-Based Nanoformulations as an Emerging Therapeutic Strategy for Cancer

Resveratrol is a polyphenolic stilbene derivative widely present in grapes and red wine. Broadly known for its antioxidant effects, numerous studies have also indicated that it exerts anti-inflammatory and antiaging abilities and a great potential in cancer therapy. Regrettably, the oral administration of resveratrol has pharmacokinetic and physicochemical limitations such as hampering its effects so that effective administration methods are demanding to ensure its efficiency. Thus, the present review explores the published data on the application of resveratrol nanoformulations in cancer therapy, with the use of different types of nanodelivery systems. Mechanisms of action with a potential use in cancer therapy, negative effects, and the influence of resveratrol nanoformulations in different types of cancer are also highlighted. Finally, the toxicological features of nanoresveratrol are also discussed.

Increased Water-Solubility and Maintained Antioxidant Power of Resveratrol by Its Encapsulation in Vitamin E TPGS Micelles: A Potential Nutritional Supplement for Chronic Liver Disease

Children affected by chronic liver disease exhibit impaired neurocognitive development and growth due to the low absorption and digestion of nutrients. Furthermore, malnutrition is an adverse prognostic factor in liver transplantation as it is associated with an increase in morbidity and mortality. D-α-tocopheryl-polyethylene-glycol-succinate (TPGS) is currently administered per os as a vitamin E source to improve children's survival and well-being; however, TPGS alone does not reverse spinocerebellar degeneration and lipid peroxidation. To potentiate the effects of TPGS, we loaded micelles with resveratrol (RES), a natural polyphenol, with antioxidant and antiinflammatory activities, which has demonstrated protective action in the liver. Firstly, we investigated the suitability of TPGS to encapsulate RES in micelles by means of a phase-solubility study, then RES-TPGS formulations were prepared via solvent casting and solvent diffusion evaporation methods. RES-TPGS colloidal dispersions showed small mean diameters (12 nm), low polydispersity, and quite neutral Zeta potentials. The formulations showed a sustained drug release and a good drug loading capacity, further confirmed by infrared spectroscopy and differential scanning calorimetry. RES-TPGSs exhibited unaltered antioxidant activity compared to pristine RES via the DPPH assay and a significant reduction in toxicity compared to empty TPGS on HaCaT cells. Thus, RES-TPGS micelles may overcome the challenges of current liver disease therapy by providing more protective effects thanks to the antioxidant activity of RES and by reducing the surfactant toxicity on normal cells.

Oxyresveratrol: Sources, Productions, Biological Activities, Pharmacokinetics, and Delivery Systems

Oxyresveratrol has recently attracted much research attention due to its simple chemical structure and diverse therapeutic potentials. Previous reviews describe the chemistry and biological activities of this phytoalexin, but additional coverage and greater accessibility are still needed. The current review provides a more comprehensive summary, covering research from 1955 to the present year. Oxyresveratrol occurs in both gymnosperms and angiosperms. However, it has never been reported in plants in the subclass Sympetalae, and this point might be of both chemotaxonomic and biosynthetic importance. Oxyresveratrol can be easily obtained from plant materials by conventional methods, and several systems for both qualitative and quantitative analysis of oxyresveratrol contents in plant materials and plant products are available. Oxyresveratrol possesses diverse biological and pharmacological activities such as the inhibition of tyrosinase and melanogenesis, antioxidant and anti-inflammatory activities, and protective effects against neurological disorders and digestive ailments. However, the unfavorable pharmacokinetic properties of oxyresveratrol, including low water solubility and poor oral availability and stability, have posed challenges to its development as a useful therapeutic agent. Recently, several delivery systems have emerged, with promising outcomes that may improve chances for the clinical study of oxyresveratrol.

Resveratrol and Pterostilbene Inhibit SARS-CoV-2 Replication in Air-Liquid Interface Cultured Human Primary Bronchial Epithelial Cells

The current COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has an enormous impact on human health and economy. In search for therapeutic options, researchers have proposed resveratrol, a food supplement with known antiviral, anti-inflammatory, and antioxidant properties as an advantageous antiviral therapy for SARS-CoV-2 infection. Here, we provide evidence that both resveratrol and its metabolically more stable structural analog, pterostilbene, exhibit potent antiviral properties against SARS-CoV-2 in vitro. First, we show that resveratrol and pterostilbene antiviral activity in African green monkey kidney cells. Both compounds actively inhibit virus replication within infected cells as reduced virus progeny production was observed when the compound was added at post-inoculation conditions. Without replenishment of the compound, antiviral activity was observed up to roughly five rounds of replication, demonstrating the long-lasting effect of these compounds. Second, as the upper respiratory tract represents the initial site of SARS-CoV-2 replication, we also assessed antiviral activity in air-liquid interface (ALI) cultured human primary bronchial epithelial cells, isolated from healthy volunteers. Resveratrol and pterostilbene showed a strong antiviral effect in these cells up to 48 h post-infection. Collectively, our data indicate that resveratrol and pterostilbene are promising antiviral compounds to inhibit SARS-CoV-2 infection. Because these results represent laboratory findings in cells, we advocate evaluation of these compounds in clinical trials before statements are made whether these drugs are advantageous for COVID-19 treatment.

Cyclodextrin Nanosponges Inclusion Compounds Associated with Gold Nanoparticles for Potential Application in the Photothermal Release of Melphalan and Cytoxan

This article describes the synthesis and characterization of β-cyclodextrin-based nano-sponges (NS) inclusion compounds (IC) with the anti-tumor drugs melphalan (MPH) and cytoxan (CYT), and the addition of gold nanoparticles (AuNPs) onto both systems, for the potential release of the drugs by means of laser irradiation. The NS-MPH and NS-CYT inclusion compounds were characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), UV-Vis, and proton nuclear magnetic resonance (1H-NMR). Thus, the inclusion of MPH and CYT inside the cavities of NSs was confirmed. The association of AuNPs with the ICs was confirmed by SEM, EDS, TEM, and UV-Vis. Drug release studies using NSs synthesized with different molar ratios of β-cyclodextrin and diphenylcarbonate (1:4 and 1:8) demonstrated that the ability of NSs to entrap and release the drug molecules depends on the crosslinking between the cyclodextrin monomers. Finally, irradiation assays using a continuous laser of 532 nm showed that photothermal drug release of both MPH and CYT from the cavities of NSs via plasmonic heating of AuNPs is possible.

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.

Solubilization of Trans-Resveratrol in Some Mono-Solvents and Various Propylene Glycol + Water Mixtures

This research deals with the determination of solubility, Hansen solubility parameters, dissolution properties, enthalpy-entropy compensation, and computational modeling of a naturally-derived bioactive compound trans-resveratrol (TRV) in water, methanol, ethanol, n-propanol, n-butanol, propylene glycol (PG), and various PG + water mixtures. The solubility of TRV in six different mono-solvents and various PG + water mixtures was determined at 298.2-318.2 K and 0.1 MPa. The measured experimental solubility values of TRV were regressed using six different computational/theoretical models, including van't Hoff, Apelblat, Buchowski-Ksiazczak λh, Yalkowsly-Roseman, Jouyban-Acree, and van't Hoff-Jouyban-Acree models, with average uncertainties of less than 3.0%. The maxima of TRV solubility in mole fraction was obtained in neat PG (2.62 × 10-2) at 318.2 K. However, the minima of TRV solubility in the mole fraction was recorded in neat water (3.12 × 10-6) at 298.2 K. Thermodynamic calculation of TRV dissolution properties suggested an endothermic and entropy-driven dissolution of TRV in all studied mono-solvents and various PG + water mixtures. Solvation behavior evaluation indicated an enthalpy-driven mechanism as the main mechanism for TRV solvation. Based on these data and observations, PG has been chosen as the best mono-solvent for TRV solubilization.

A physicochemical, thermodynamical, structural and computational evaluation of kynurenic acid/cyclodextrin complexes

In this work, the interaction between Kynurenic acid (KYNA) and several natural and modified cyclodextrins (CDs) is carried out. Among all the CD tested, HPβ-CD showed the strongest complexation constant (K_F), with a value of 270.94 ± 29.80 M^-1. Between natural (α- and β-) CDs, the complex of KYNA with β-CD was the most efficient. The inclusion complex of KYNA with CDs showed a strong influence of pH and temperature. The K_F value decreased at high pH values, when the pK_a was passed. Moreover, an increase of the temperature caused a decrease in the K_F values. The thermodynamic parameters of the complexation (ΔH°, ΔS° and ΔG°) were studied with negative entropy, enthalpy and spontaneity of the process at 25 °C. Moreover, the inclusion complex was also characterized using FTIR and TGA. Finally, molecular docking calculations provided different interactions and their influence in the complexation constant.

Buccal Resveratrol Delivery System as a Potential New Concept for the Periodontitis Treatment

The health benefits of resveratrol have been proven to inhibit the development of numerous diseases. A frequent limitation in its use is a low bioavailability stemming from a poor solubility and fast enterohepatic metabolism. Thus, the aim of the research was to investigate the possibility to formulate mucoadhesive cyclodextrin- and xanthan gum-based buccal tablets in order to increase the solubility of resveratrol and to eliminate bypass enterohepatic metabolism. Systems of resveratrol with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) prepared by the dry mixing method (ratio 1:1) were selected for the of tablets where xanthan gum was used as a mucoadhesive agent. They were identified on the basis of PXRD, FT-IR analysis. Tablets F1 (with α-CD), F2 (with β-CD) and F3 (with γ-CD) were characterized by the highest compactibility as well as by favorable mucoadhesive properties. Resveratrol release from these tablets was delayed and controlled by diffusion. The tablets prepared in the course of this study appear to constitute promising resveratrol delivery systems and are recommended to increase the effectiveness of the treatment in many diseases, particularly periodontitis.

Study of the fluorescence and interaction between cyclodextrins and neochlorogenic acid, in comparison with chlorogenic acid

Neochlorogenic acid, a less-studied isomer of chlorogenic acid, has been seen to posses antioxidant, antifungal, anti-inflammatory and anticarcinogenic effects, which makes it an interesting candidate for incorporation in functional foods. However, its poor solubility in water and susceptibility to oxidation make such a task difficult. To overcome that, its encapsulation in cyclodextrins (CDs) is proposed. The fluorescence of neochlorogenic acid in different pH conditions was analyzed, and caffeic acid was proved to be the fluorescent moiety in the molecule. An encapsulation model whereby the ligand poses two potential complexation sites (caffeic and D-(-)-quinic moieties), showed that α-CD and HP-β-CD formed the best inclusion complexes with neochlorogenic acid, followed by M-β-CD, β-CD and γ-CD. Molecular docking with the two best CDs gave better scores for α-CD, despite HP-β-CD providing stabilization through H-bonds. The encapsulation of chlorogenic acid led to a similar CD order and scores, although constants were higher for α-CD, β-CD and M-β-CD, lower for HP-β-CD, and negligible for γ-CD. The protonation state affected these results leading to a different order of CD preference. The solubility and the susceptibility to oxidation of neochlorogenic acid improved after complexation with α-CD and HP-β-CD, while the antioxidant activity of both isomers was maintained.

Cyclodextrin nanosponge for the GSH-mediated delivery of Resveratrol in human cancer cells

Smart drug delivery systems are required for the site-specific drug targeting to enhance the therapeutic efficiency of a drug. Resveratrol (RV) is a polyphenolic compound with anti-cancer activity. However, its poor aqueous solubility and non-selectivity are the major challenges for its employment in cancer therapy. In this work, we present the synthesis of RV-loaded glutathione responsive cyclodextrin nanosponges (RV-GSH-NSs) to improve the therapeutic efficiency and selective delivery of RV. The drug loading and encapsulation efficiency were 16.12% and 80.64%, respectively. The in vitro release profile confirmed that RV release was enhanced in response to external glutathione (GSH). Nude NSs were not toxic per se to human fibroblasts when administered for up to 72 h at the highest dose. Cell internalization studies confirmed that RV-GSH-NSs were preferentially up-taken by tumor cells compared to non-tumorigenic cells. Accordingly, RV showed selective toxicity to cancer cells compared to normal cells. GSH depletion by buthionine sulfoximine, a potent inhibitor of its synthesis, reflected in a significant decrease of the NSs accumulation, and consequently resulted in a drastic reduction of RV-mediated toxic effects in cancer cells. These findings demonstrate that GSH- responsive NSs represent an effective delivery system for targeting cancer cells by harnessing the differential tumor characteristics in terms of redox status in parallel with the limitation of side effects toward normal cells.

Enhanced Oral Bioavailability of Resveratrol by Using Neutralized Eudragit E Solid Dispersion Prepared via Spray Drying

In this study, we designed amorphous solid dispersions based on Eudragit E/HCl (neutralized Eudragit E using hydrochloric acid) to maximize the dissolution of trans-resveratrol. Solid-state characterization of amorphous solid dispersions of trans-resveratrol was performed using powder X-ray diffraction, scanning electron microscopy, and particle size measurements. In addition, an in vitro dissolution study and an in vivo pharmacokinetic study in rats were carried out. Among the tested polymers, Eudragit E/HCl was the most effective solid dispersion for the solubilization of trans-resveratrol. Eudragit E/HCl significantly inhibited the precipitation of trans-resveratrol in a pH 1.2 dissolution medium in a dose-dependent manner. The amorphous Eudragit E/HCl solid dispersion at a trans-resveratrol/polymer ratio of 10/90 exhibited a high degree of supersaturation without trans-resveratrol precipitation for at least 48 h by the formation of Eudragit E/HCl micelles. In rats, the absolute oral bioavailability (F%) of trans-resveratrol from Eudragit E/HCl solid dispersion (10/90) was estimated to be 40%. Therefore, trans-resveratrol-loaded Eudragit E/HCl solid dispersions prepared by spray drying offer a promising formulation strategy with high oral bioavailability for developing high-quality health supplements, nutraceutical, and pharmaceutical products.

Inclusion Complex of Resveratrol with γ-Cyclodextrin as a Functional Ingredient for Lemon Juices

Microencapsulated resveratrol (RSV) is a pertinent ingredient in functional foods to be used in the prevention and management of cardiovascular diseases. Gamma-cyclodextrin (γ-CD) was evaluated for its RSV inclusion ability. Inclusion procedures comprised mixing equal concentration of an aqueous solution of γ-CD with an ethanol solution of RSV and freeze-drying to obtain a solid material. Solid-state characterization by vibrational spectroscopy, thermogravimetry, and powder X-ray diffraction (PXRD) confirmed the formation of the γ-CD·RSV complex in a ratio of 1:1. PXRD suggested that cyclodextrin molecules in the complex are stacked in infinite channels holding the RSV inside, with a wide inter-channel space where 14 water molecules are retained. Fresh lemon juices supplemented with 0.625 mg/mL of RSV in its free (RSV-juice) or complexed (γ-CD·RSV-juice) form were stored along 28 days under dark and room temperature or at 4 °C. Initially, the RSV level in γ-CD·RSV-juice was about nine times higher than in RSV-juice (43.1% and 4.8%, respectively), suggesting that the RSV complexation promoted its solubility in the lemon juice, a fact that was still noticed after 28 days of storage. Moreover, regardless the fact that the antioxidant capacity was similar among the juices, the loss of antiradical ABTS•+ capacity in γ-CD·RSV-juice was reduced compared to that of the RSV-juice. Overall, this study allowed concluding that γ-CD can serve as a carrier of RSV, promoting its solubility and eventually protecting its antioxidant stability in lemon juices for at least 28 days.

The use of plant extracts and their phytochemicals for control of toxigenic fungi and mycotoxins

Mycotoxins present a great concern to food safety and security due to their adverse health and socio-economic impacts. The necessity to formulate novel strategies that can mitigate the economic and health effects associated with mycotoxin contamination of food and feed commodities without any impact on public health, quality and nutritional value of food and feed, economy and trade industry become imperative. Various strategies have been adopted to mitigate mycotoxin contamination but often fall short of the required efficacy. One of the promising approaches is the use of bioactive plant components/metabolites synergistically with mycotoxin-absorbing components in order to limit exposure to these toxins and associated negative health effects. In particular, is the fabrication of β-cyclodextrin-based nanosponges encapsulated with bioactive compounds of plant origin to inhibit toxigenic fungi and decontaminate mycotoxins in food and feed without leaving any health and environmental hazard to the consumers. The present paper reviews the use of botanicals extracts and their phytochemicals coupled with β-cyclodextrin-based nanosponge technology to inhibit toxigenic fungal invasion and detoxify mycotoxins.

Lifespan extension in Caenorhabditis elegans by oxyresveratrol supplementation in hyper-branched cyclodextrin-based nanosponges

In this work, the increase of the Caenorhabditis elegans (C. elegans) lifespan extension using hyper-branched cyclodextrin-based nanosponges (CD-NS) complexing oxyresveratrol (OXY), and the possible inhibition of C. elegans phosphodiesterase type 4 (PDE4) were evaluated. The titration displacement of fluorescein was used to calculate the apparent complexation constant (K_F) between CD-NS and OXY. Moreover, PDE4 was expressed in E. coli, purified and refolded in presence of cyclodextrins (CDs) to study its possible inhibition as pharmacological target of OXY. The apparent activity was characterized and the inhibitory effect of OXY on PDE4 displayed a competitive in vitro inhibition corroborated in silico. A maximum increase of the in vivo life expectancy of about 9.6% of using OXY/CD-NS complexes in comparison with the control was obtained, in contrast to the 6.5% obtained with free OXY. No effect on lifespan or toxicity with CD-NS alone was found. These results as a whole represent new opportunities to use OXY and CD-NS in lifespan products.

Resveratrol Delivery from Implanted Cyclodextrin Polymers Provides Sustained Antioxidant Effect on Implanted Neural Probes

Intracortical microelectrodes are valuable tools used to study and treat neurological diseases. Due in large part to the oxidative stress and inflammatory response occurring after electrode implantation, the signal quality of these electrodes decreases over time. To alleviate this response, resveratrol, a natural antioxidant which elicits neuroprotective effects through reduction of oxidative stress, was utilized. This work compares traditional systemic delivery of resveratrol to the novel cyclodextrin polymer (pCD) local delivery approach presented herein, both in vitro and in vivo. The pCD displayed an extended resveratrol release for 100 days, as well as 60 days of free radical scavenging activity in vitro. In vivo results indicated that our pCD delivery system successfully delivered resveratrol to the brain with a sustained release for the entire short-duration study (up to 7 days). Interestingly, significantly greater concentrations of resveratrol metabolites were found at the intracortical probe implantation site compared to the systemic administration of resveratrol. Together, our pilot results provide support for the possibility of improving the delivery of resveratrol in an attempt to stabilize long-term neural interfacing applications.

History of Cyclodextrin Nanosponges

Nowadays, research in the field of nanotechnology and nanomedicine has become increasingly predominant, focusing on the manipulation and development of materials on a nanometer scale. Polysaccharides have often been used as they are safe, non-toxic, hydrophilic, biodegradable and are low cost. Among them, starch derivatives and, in particular, cyclodextrin-based nanosponges (CD NSs) have recently emerged due to the outstanding properties attributable to their peculiar structure. In fact, alongside the common polysaccharide features, such as the presence of tunable functional groups and their ability to interact with biological tissues, thus giving rise to bioadhesion, which is particularly useful in drug delivery, what makes CD NSs unique is their three-dimensional network made up of crosslinked cyclodextrin units. The name “nanosponge” appeared for the first time in the 1990s due to their nanoporous, sponge-like structure and responded to the need to overcome the limitations of native cyclodextrins (CDs), particularly their water solubility and inability to encapsulate charged and large molecules efficiently. Since CD NSs were introduced, efforts have been made over the years to understand their mechanism of action and their capability to host molecules with low or high molecular weight, charged, hydrophobic or hydrophilic by changing the type of cyclodextrin, crosslinker and degree of crosslinking used. They enabled great advances to be made in various fields such as agroscience, pharmaceutical, biomedical and biotechnological sectors, and NS research is far from reaching its conclusion. This review gives an overview of CD NS research, focusing on the origin and key points of the historical development in the last 50 years, progressing from relatively simple crosslinked networks in the 1960s to today’s multifunctional polymers. The approach adopted in writing the present study consisted in exploring the historical evolution of NSs in order to understand their role today, and imagine their future.

Pure Trans-Resveratrol Nanoparticles Prepared by A Supercritical Antisolvent Process Using Alcohol and Dichloromethane Mixtures: Effect of Particle Size on Dissolution and Bioavailability in Rats

The aim of this study was to prepare pure trans-resveratrol nanoparticles without additives (surfactants, polymers, and sugars) using a supercritical antisolvent (SAS) process with alcohol (methanol or ethanol) and dichloromethane mixtures. In addition, in order to investigate the effect of particle size on the dissolution and oral bioavailability of the trans-resveratrol, two microparticles with different sizes (1.94 μm and 18.75 μm) were prepared using two different milling processes, and compared to trans-resveratrol nanoparticles prepared by the SAS process. The solid-state properties of pure trans-resveratrol particles were characterized. By increasing the percentage of dichloromethane in the solvent mixtures, the mean particle size of trans-resveratrol was decreased, whereas its specific surface area was increased. The particle size could thus be controlled by solvent composition. Trans-resveratrol nanoparticle with a mean particle size of 0.17 μm was prepared by the SAS process using the ethanol/dichloromethane mixture at a ratio of 25/75 (w/w). The in vitro dissolution rate of trans-resveratrol in fasted state-simulated gastric fluid was significantly improved by the reduction of particle size, resulting in enhanced oral bioavailability in rats. The absolute bioavailability of trans-resveratrol nanoparticles was 25.2%. The maximum plasma concentration values were well correlated with the in vitro dissolution rate. These findings clearly indicate that the oral bioavailability of trans-resveratrol can be enhanced by preparing pure trans-resveratrol nanoparticles without additives (surfactants, polymers, and sugars) by the SAS process. These pure trans-resveratrol nanoparticles can be applied as an active ingredient for the development of health supplements, pharmaceutical products, and cosmetic products.

Preparation and Evaluation of Resveratrol-Loaded Composite Nanoparticles Using a Supercritical Fluid Technology for Enhanced Oral and Skin Delivery

We created composite nanoparticles containing hydrophilic additives using a supercritical antisolvent (SAS) process to increase the solubility and dissolution properties of trans-resveratrol for application in oral and skin delivery. Physicochemical properties of trans-resveratrol-loaded composite nanoparticles were characterized. In addition, an in vitro dissolution-permeation study, an in vivo pharmacokinetic study in rats, and an ex vivo skin permeation study in rats were performed. The mean particle size of all the composite nanoparticles produced was less than 300 nm. Compared to micronized trans-resveratrol, the trans-resveratrol/hydroxylpropylmethyl cellulose (HPMC)/poloxamer 407 (1:4:1) nanoparticles with the highest flux (0.792 μg/min/cm²) exhibited rapid absorption and showed significantly higher exposure 4 h after oral administration. Good correlations were observed between in vitro flux and in vivo pharmacokinetic data. The increased solubility and flux of trans-resveratrol generated by the HPMC/surfactant nanoparticles increased the driving force on the gastrointestinal epithelial membrane and rat skin, resulting in enhanced oral and skin delivery of trans-resveratrol. HPMC/surfactant nanoparticles produced by an SAS process are, thus, a promising formulation method for trans-resveratrol for healthcare products (owing to their enhanced absorption via oral administration) and for skin application with cosmetic products.