Search Results (706)

Tetrahydroprotoberberine alkaloids (THPBs) are bioactive natural products bearing stereogenic centers that frequently exhibit enantiomer-specific pharmacological effects. Xylopinine (XPN), a representative THPB, shows cytotoxic, antimicrobial, and antimalarial activity in vitro, and displays pronounced stereoselectivity in vivo, with the naturally occurring (S)-enantiomer emphasizing the need for reliable enantioselective analysis. In this study, we present the synthesis of racemic XPN from norlaudanosine, and its first comprehensive cyclodextrin-assisted capillary electrophoresis screening dedicated to the enantioseparation of XPN. Sulfated- and sulfobutyl-ether-β-cyclodextrin (S-β-CyD, SBE-β-CyD) provided efficient resolution (R_s > 3), while heptakis-(6-deoxy-6-(2-carboxyethyl)thio)-β-CyD (subetadex, SBX) yielded outstanding separation (R_s > 9). The enantiomer migration order was consistently R,S, except when using SBE-β-CyD, which showed the inverse sequence. Chiral HPLC using a Chiralpak AD column in polar organic mode with methanol modified with 0.1% diethylamine as mobile phase enabled the semi-preparative isolation of XPN enantiomers, with the (S)-enantiomer exceeding 95% purity. The absolute configuration was confirmed by circular dichroism spectroscopy. ¹H NMR titration and 2D rotating-frame nuclear Overhauser effect correlation spectroscopy (ROESY) consistently revealed multi-site recognition of XPN by SBX, supporting the inclusion of both aromatic rings (A and D). Full article

Carmustine (BCNU) is a powerful alkylating agent primarily used in the chemotherapeutic treatment of malignant brain tumors. However, its clinical application faces significant constraints due to its lipophilicity, low thermal stability, and rapid degradation in physiological environments. To tackle these challenges, our research aimed at the development and detailed characterization of α-cyclodextrin (α-CD) inclusion complexes (ICs) with BCNU employing three different synthesis techniques: co-grinding, cryomilling, and co-precipitation. The selected synthetic methods displayed variations dependent on the technique used, affecting the efficiency, inclusion ratios, and drug-loading capacities, with co-precipitation achieving the most favorable complexation parameters. Structural elucidation through ¹H NMR chemical shifts analysis indicated that only partial inclusion of BCNU occurred within α-CD in ICs produced via co-grinding, while cryomilling and co-precipitation allowed for complete inclusion. Multimodal spectroscopic analyses (FT-IR, UV-Vis, ¹³C CP MAS NMR, and ESI-MS) further substantiated the effective encapsulation of BCNU within α-CD, and systematic solubility assessments via Job’s continuous variation and the Benesi-Hildebrand method revealed a 1:1 host-guest stoichiometry. The ICs obtained were evaluated for BCNU release in vitro at pH levels of 4, 5, 6.5, and 7.4. The mechanism of BCNU drug release was determined to be Fickian diffusion, with the highest cumulative release noted in the acidic microenvironment. These findings collectively validate the effectiveness of α-CD as a functional excipient for the modulation of BCNU’s physicochemical properties through non-covalent complexation. This strategy shows potential for increasing the stability and solubility of BCNU, which may enhance its therapeutic effectiveness in the treatment of brain tumors. Full article

Cyclodextrins in metal oxide nanoparticles (NPs) serve as stabilizing, dispersing, and functionalizing agents that enhance antimicrobial performance through better nanoparticle stability, synergistic action, and potential controlled release mechanisms, making them ideal for advanced biomedical and environmental antimicrobial applications. In this study, NPs of vanadium pentoxide (V₂O₅) were obtained by the precipitation method, and, following a supramolecular assembly, were synthesized using the impregnation method via addition of β-cyclodextrin (BCD) and its derivatives, such as hydroxypropyl-β-cyclodextrin (HCD) and methyl-β-cyclodextrin (MCD). The formation of the V₂O₅:CDs was driven by non-covalent host–guest interactions, leading to a stable supramolecular structure with enhanced physicochemical properties. Morphological analysis using scanning electron microscopy (SEM) revealed uniformly distributed V₂O₅ NPs within the CD matrix. Structural characterization was further supported by proton nuclear magnetic resonance (NMR) spectroscopy, which confirmed the inclusion interactions between V₂O₅ and CDs. The synthesized NPs demonstrated significant antimicrobial activity against Gram-positive and fungal strains, indicating a synergistic enhancement in bioactivity due to the supramolecular architecture. This work highlights the potential of CD-assisted V₂O₅ NPs as promising antimicrobial agents for biomedical and environmental applications. Full article

Background/Objectives: Pinostilbene is a naturally occurring methoxylated stilbene with many beneficial health properties, including antioxidant, antimicrobial and neuroprotective activities. This stilbene has also been shown to possess anticancer or cytotoxic activity in some cancers. As in the case of other stilbenes, pinostilbene is very labile, degrades rapidly under stress conditions and is poorly water-soluble, which poses a drawback to its use as a drug. This work aims to provide further insights into its cytotoxicity activity in a colon cancer cell line and to overcome its physicochemical limitations by encapsulating the molecule in cyclodextrins. Methods: The anticancer activity was evaluated in vitro in Caco-2 colorectal cells using the neutral red assay. Subsequently, a screening of cyclodextrins was carried out to determine the one with the highest encapsulation constant, as well as the encapsulation stoichiometry, using fluorescence spectroscopy and molecular docking predictions. The formation of the inclusion complexes was checked by differential scanning calorimetry and scanning electron microscopy. The protective effect of cyclodextrins on pinostilbene release was monitored through spectrophotometric measurements over time. Results: Pinostilbene showed in vitro cytotoxicity activity in Caco-2 colorectal cells by the neutral red assay. This study revealed that the cyclodextrin with the highest encapsulation constant was the hydroxypropyl-β-cyclodextrin (K_F = 10,074.45 ± 503.72 M⁻¹), and the encapsulation stoichiometry was 1:1. DSC and SEM assays confirmed the formation of these inclusion complexes. Cyclodextrins were able to satisfactorily reduce pinostilbene degradation from 31% to less than 15% after 3 months, as well as increase its water solubility up to 10 times and enhance its release as a function of the pH of the medium. Conclusions: Pinostilbene is a promising drug candidate with strong in vitro antiproliferative activity. Many of its physicochemical limitations can be overcome with cyclodextrins, which opens the door to its future use in the pharmaceutical and food industries. Full article

Nerolidol (REL), a sesquiterpene with cis and trans isomers, exhibits diverse bioactive and sensory properties. In this study, we integrate single-crystal X-ray diffraction (SC-XRD), molecular docking, molecular dynamics (MD) simulations, and MM/GBSA binding free energy calculations to investigate its inclusion behavior in β-cyclodextrin (β-CD). Crystallization from a cis/trans mixture yielded a complex containing exclusively the trans isomer, forming a 2:1 host–guest assembly where a head-to-head β-CD dimer encapsulates one trans-REL molecule in an extended conformation. Computational models of cis-REL (bent c1 and extended c8 conformers) also stabilized within the β-CD cavity, with the extended conformer showing the most favorable dynamics. The computed binding affinities for all complexes differed by less than the estimated MM/GBSA uncertainty, indicating no statistically significant preference. Since cis/trans separation of nerolidol and related long-chain terpenoids is of considerable interest, our findings suggest that crystallization selectivity in β-CD inclusion complexes cannot be rationalized solely by binding affinity; instead, it likely arises from crystal packing forces and conformational preferences that govern the solid-state assembly. Full article

An eco-friendly composite coating was developed for blueberry preservation through the incorporation of thymol-loaded β-cyclodextrin microcapsules (THY@β-CD) into a potato starch (PO) matrix. Microencapsulation at an optimal wall-to-core ratio of 13:1 achieved a THY encapsulation efficiency of 73.24%. Structural analyses confirmed the successful formation of an inclusion complex, which enhanced thermal stability and provided a controlled release profile governed by Fickian diffusion mechanisms. When applied to blueberries, the coating significantly reduced weight loss by 22%, delayed softening, and more effectively preserved anthocyanin content compared to uncoated fruit during 10-day storage. Furthermore, it well-maintained the sensory quality and visual appeal of the fruit. These results demonstrate that the THY@β-CD/PO coating synergistically integrates sustained antimicrobial delivery with matrix compatibility, offering a promising natural alternative to synthetic preservatives for extending the shelf life of blueberries. Full article

Methicillin-resistant S. aureus is a problematic pathogen due to its high-risk infections and resistance mechanisms. To fight against this bacterium, novel antimicrobial sources and new delivery systems must be developed. Antimicrobial polyurethanes for developing biomaterials can function as preventive strategies. In this study, we explore the synthesis of partially renewable polyurethanes as biomaterial carriers of novel antimicrobials. An antibacterial extract from a Streptomyces sp. strain and its inclusion complexes with β-cyclodextrin, used as an additional protective approach, were incorporated into castor oil-based polyurethane films through bulk or surface loading. The inclusion complexes were characterized to confirm host–guest interactions. The films were characterized by FTIR, XRD spectra, surface SEM images, hydrophilicity, thermal stability, and mechanical performance. FTIR suggested successful polyurethane synthesis. The polymers were semicrystalline and thermally stable until 260 °C, and Tg ranged between −16.9 and −9 °C. Bulk modification decreased the mechanical performance of the films. Surface modification promoted good antibacterial performance but cytotoxic potential against HDFa cells. However, PU active films showed favorable properties and hemocompatibility, making them a promising alternative for applications such as short-term dressings, serving as an antimicrobial delivery system and a preventive strategy against methicillin-resistant S. aureus. Full article

Background/Objectives: In the past two decades, the primary therapeutic use of sildenafil has shifted significantly, from the treatment of angina to managing erectile dysfunction, and since the early 2000s it has been used in the treatment of pulmonary hypertension, particularly pulmonary arterial hypertension. Sildenafil is used as a citrate salt; after oral administration, it presents an absorption of ~90% and an absolute bioavailability of 38%, due to the first-pass effect, such that it belongs to class II of the Biopharmaceutics Classification System. Currently, studies are seeking to obtain new pharmaceutical formulations with an optimized biopharmaceutical profile. In this study, an inclusion complex of sildenafil citrate and 2-hydroxypropyl-beta-cyclodextrin in a molar ratio of 1:1 was obtained and its pharmaceutical compatibility with six pharmaceutical excipients was assessed. For three of these excipients, the presence of chemical interactions with sildenafil citrate has been presented in the literature, and for the other three, compatibility has not been evaluated. Methods: To certify the stoichiometry of the obtained inclusion complex molecular modeling, Job’s method and the Benesi–Hildebrand method were employed. Furthermore, we have described the inclusion complex and the obtained binary mixtures via ATR-FTIR and thermal (TG/DTG and DSC) analysis. Results: The results indicated a lack of chemical interactions between the inclusion complex and the six pharmaceutical excipients at ambient temperature (confirmed by ATR–FTIR investigations) and the presence of chemical interactions between the inclusion complex and three of the excipients when the mixture was heated under non-isothermal conditions (TG/DTG and DSC investigations). Conclusions: This study describes the inclusion complex between sildenafil citrate and 2-hydroxypropyl-beta-cyclodextrin in a molar ratio of 1:1 and its compatibility with several pharmaceutical excipients, results with further applications in the preformulation stage of novel delivery systems. Full article

Cyclodextrins, since their discovery in the late 19th century, have gained tremendous interest in biomedical research, beginning with their recognition as safe pharmaceutical excipients, and continuing with exploiting their potential for enhancing the therapeutic response of active pharmaceutical ingredients, and also to be used as drugs for specific medical purposes. This review presents an integrative perspective on amphiphilic cyclodextrins, the manuscript being divided into two parts, one devoted to the properties of amphiphilic cyclodextrins, while the second one is dedicated to their biomedical applications, with an emphasis on cancer therapy. Full article

This study aimed to analyze whether the enhancement of the biopharmaceutical efficiency of mebendazole, a poorly water-soluble anthelmintic drug, significantly improves its antiparasitic activity in a murine model of trichinellosis. Objectives: Two advanced oral formulations were developed, polyvinyl alcohol-derived nanoparticles (NP) and β-cyclodextrin citrate inclusion complexes (Comp), both employing mebendazole as an anthelmintic agent. The primary objective of this work is to treat trichinellosis, an infection with severe chronic effects. Methods: The physicochemical characteristics as well as the in vivo performance of the NP and Comp formulations were assessed. The in vivo studies involved the bioavailability analysis, comparing drug absorption between the pure drug and the novel formulations, as well as the in vitro anthelmintic activity and in vivo therapeutic efficacy against Trichinella spiralis encysted muscle larvae. The in vivo efficacy was evaluated during the parenteral stage of T. spiralis infection in male and female mice from two genetically distinct lines differing in mebendazole pharmacokinetic parameters and susceptibility to the parasite. Results: The formulations exhibited smaller particle sizes and improved dissolution properties compared to pure MBZ. The pharmacokinetics studies indicate that NP and Comp significantly improved MBZ bioavailability. Both NP and Comp significantly increased mebendazole’s anthelmintic activity against the encysted parasites, which would be attributed to the improved MBZ absorption. The formulations overcome the drug’s poor solubility and low bioavailability limitations, resulting in a higher plasma concentration of the active drug, even at low doses. Conclusions: These findings suggest that the newly designed mebendazole formulations are suitable for treating T. spiralis chronic infection and highlight a potential improvement in the pharmacological treatment of trichinellosis. Full article

The escalating crisis of multidrug resistance, together with the persistence of antibiotic residues in clinical and environmental matrices, demands integrated strategies that couple sensitive detection, efficient decontamination, and controlled delivery. However, current techniques for quantifying avibactam (AVI)—a broad-spectrum β-lactamase inhibitor—such as HPLC-UV lack the sensitivity and specificity required for both therapeutic drug monitoring and environmental surveillance. Encapsulation of AVI within cyclodextrins (CDs) may simultaneously enhance its stability, bioavailability, and detectability, while the high binding affinities of CDs position them as molecular traps capable of scavenging residual AVI. In this study, the inclusion complexation of AVI with various CDs was examined through molecular dynamics (MD) simulations, experimental isothermal titration calorimetry (ITC), and non-covalent interaction (NCI) analysis. Stable 1:1 inclusion complexes were observed between AVI and β-cyclodextrin (β-CD), 2,6-dimethyl-β-cyclodextrin (DM-β-CD), and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), with standard Gibbs free energies of binding (ΔG°) of –3.64, –3.24, and –3.11 kcal/mol, respectively. In contrast, γ-cyclodextrin (γ-CD) exhibited significantly weaker binding (ΔG° = –2.25 kcal/mol). DFT-based NCI analysis revealed that cooperative interaction topology and cavity complementarity, rather than the sheer number of localized contacts, govern complex stability. Combined computational and experimental data establish β-CD derivatives as effective supramolecular hosts for AVI, despite an entropic penalty in the DM-β-CD/AVI complex. These CD–AVI affinities support the development of improved analytical methodologies and pharmaceutical formulations, and they also open avenues for decontamination strategies based on molecular trapping of AVI. Full article

Oxidative stress is one of the key elements in lung-related complications such as cystic fibrosis, acute lung injury, pulmonary hypertension, bronchopulmonary dysplasia, chronic airway diseases, lung cancer, COVID-19, and many others. Antioxidant and anti-inflammatory therapy can be considered as supportive alternatives in their management. However, most naturally derived antioxidants face issues with poor aqueous solubility and stability, which hinder their clinical utility. Remarkably, local pulmonary delivery circumvents the severe limitations of oral delivery, including hepatic first-pass metabolism and organ toxicity, and enables a higher drug payload in the lungs. Here, in this review, we present cyclodextrin as a potential drug carrier for pulmonary administration, exploring the possibilities of its surface modification, complexation with other drug transporters, and loading of cannabidiols, siRNA, and antibodies as future trends. However, the lack of a robust physiological model for assessing the efficacy of lung-oriented drug targeting is a significant concern in its path to clinical and commercial success. Full article

Flavonoids play an important role in preventive and therapeutic research due to their significant antioxidant properties. However, their application is limited by several pharmacokinetic drawbacks, such as poor water solubility and low bioavailability. Cyclodextrin-based delivery systems offer an opportunity to overcome these disadvantages. Cyclodextrins are able to form stable, water-soluble inclusion complexes with flavonoids, thereby improving their solubility, chemical stability, and antioxidant activity. This review summarizes the structural characteristics and complexation mechanisms of various flavonoid–cyclodextrin complexes and examines how these interactions influence biological activity. Special attention is given to nanotechnological formulations—such as liposomes, nanofibers, and nanosponges—that enable targeted drug delivery and enhanced therapeutic efficacy. The aim of this review is to provide a comprehensive overview of the role of cyclodextrin-based carriers in the formulation of flavonoids and to highlight the future potential of these systems in modern therapeutics and functional product development. Full article

In this study, supramolecular inclusion complexes composed of komecosanol (Ko), a lipophilic compound derived from rice bran, and α-cyclodextrin (αCD) were prepared using a solvent-free three-dimensional (3D) ball milling method. Their physicochemical properties were examined using various techniques. Powder X-ray diffraction analysis of the ground mixture at a Ko/αCD ratio of 1/8 revealed the disappearance of diffraction peaks characteristic of Ko and the emergence of new peaks, indicating the formation of a distinct crystalline phase. Moreover, differential scanning calorimetry analysis showed the disappearance of the endothermic peaks corresponding to Ko, indicating molecular-level interactions with αCD. Near-infrared spectroscopy results suggested the formation of hydrogen bonds between the C–H groups of Ko and the O–H groups of αCD. Solid-state ¹³C CP/MAS NMR and T₁ relaxation time measurements indicated the formation of a pseudopolyrotaxane structure, while scanning electron microscopy images confirmed distinct morphological changes consistent with complex formation. These findings demonstrate that 3D ball milling facilitates the formation of Ko/αCD inclusion complexes with a supramolecular architecture, providing a novel approach to improve the formulation and bioavailability of poorly water-soluble lipophilic compounds. Full article