Synthesis of β-Cyclodextrin-Based Electrospun Nanofiber Membranes for Highly Efficient Adsorption and Separation of Methylene Blue

Water-insoluble β-cyclodextrin-based fibers were synthesized by electrospinining followed by thermal cross-linking. The fibers were characterized by field-emission scanning electron microscopic (FE-SEM) and Fourier transformed infrared spectrometer (FT-IR). The highly insoluble fraction obtained from different pH values (3-11) indicates successful cross-linking reactions and their usability in aqueous solution. After the cross-linking reaction, the fibers' tensile strength increases significantly and the BET surface area is 19.49 m(2)/g. The cross-linked fibers exhibited high adsorption capacity for cationic dye methylene blue (MB) with good recyclability. The adsorption performance can be fitted well with pseudo-second-order model and Langmuir isotherm model. The maximum adsorption capacity is 826.45 mg/g according to Langmuir fitting. Due to electrostatic repulsion, the fibers show weak adsorption toward negatively charged anionic dye methyl orange (MO). On the basis of the selective adsorption, the fiber membrane can separate the MB/MO mixture solution by dynamic filtration at a high flow rate of 150 mL/min. The fibers can maintain good fibrous morphology and high separation efficiency even after five filtration-regeneration cycles. The obtained results suggested potential applications of β-cyclodextrin-based electrospun fibers in the dye wastewater treatment field.

Recent advances in delivery of drug-nucleic acid combinations for cancer treatment

Cancer treatment that uses a combination of approaches with the ability to affect multiple disease pathways has been proven highly effective in the treatment of many cancers. Combination therapy can include multiple chemotherapeutics or combinations of chemotherapeutics with other treatment modalities like surgery or radiation. However, despite the widespread clinical use of combination therapies, relatively little attention has been given to the potential of modern nanocarrier delivery methods, like liposomes, micelles, and nanoparticles, to enhance the efficacy of combination treatments. This lack of knowledge is particularly notable in the limited success of vectors for the delivery of combinations of nucleic acids with traditional small molecule drugs. The delivery of drug-nucleic acid combinations is particularly challenging due to differences in the physicochemical properties of the two types of agents. This review discusses recent advances in the development of delivery methods using combinations of small molecule drugs and nucleic acid therapeutics to treat cancer. This review primarily focuses on the rationale used for selecting appropriate drug-nucleic acid combinations as well as progress in the development of nanocarriers suitable for simultaneous delivery of drug-nucleic acid combinations.

Preparation, characterization, and thermal stability of β-cyclodextrin/soybean lecithin inclusion complex

β-Cyclodextrin (β-CD), which is widely used to increase the stability, solubility, and bioavailability of guests, can form host-guest inclusion complexes with a wide variety of organic molecules. In this study the β-CD/soybean lecithin inclusion complex was prepared. The effect of reaction parameters such as reaction temperature, reaction time and the molar ratio of β-CD/soybean lecithin on inclusion ratio were studied. The inclusion ratio of the product prepared under the optimal conditions of β-CD/soybean lecithin molar ratio 2:1, reaction temperature 60°C reaction time 2h was 40.2%. The results of UV-vis, DSC, XRD and FT-IR spectrum indicated the formation of inclusion complex. The thermal stability experiment indicated that the thermal stability of soybean lecithin in inclusion complex was significantly improved compared with free soybean lecithin.

Biodegradable β-Cyclodextrin Conjugated Gelatin Methacryloyl Microneedle for Delivery of Water-Insoluble Drug

Transdermal delivery of water-insoluble drugs via hydrogel-based microneedle (MN) arrays is crucial for improving their therapeutic efficacies. However, direct loading of water-insoluble drug into hydrophilic matrices remains challenging. Here, a biodegradable MN array patch that is fabricated from naturally derived polymer conjugates of gelatin methacryloyl and β-cyclodextrin (GelMA-β-CD) is reported. When curcumin, an unstable and water-insoluble anticancer drug, is loaded as a model drug, its stability and solubility are improved due to the formation of an inclusion complex. The polymer-drug complex GelMA-β-CD/CUR can be formulated into MN arrays with sufficient mechanical strength for skin penetration and tunable drug release profile. Anticancer efficacy of released curcumin is observed in three-dimensional B16F10 melanoma models. The GelMA-β-CD/CUR MN exhibits relatively higher therapeutic efficacy through more localized and deeper penetrated manner compared with a control nontransdermal patch. In vivo studies also verify biocompatibility and degradability of the GelMA-β-CD MN arrays patch.

Multifunctional β-Cyclodextrin Polymer for Simultaneous Removal of Natural Organic Matter and Organic Micropollutants and Detrimental Microorganisms from Water

Natural organic matter (NOM), organic micropollutants (OMPs), and detrimental microorganisms are three major pollutants that affect water quality. To remove these pollutants, a quaternary ammonium-functionalized β-cyclodextrin polymer (β-CDP) is successfully synthesized in the aqueous phase. The N₂ and CO₂ adsorption/desorption analysis showed that the polymer mainly contains ultra-micropores (<1 nm), with a Langmuir surface area of 89 m² g^-1. Two kinds of NOM, humic acid and fulvic acid, and five OMPs, 2-naphthol (2-NO), 3-phenylphenol (3-PH), 2,4,6-trichlorophenol (2,4,6-TCP), bisphenol A (BPA), and bisphenol S (BPS), were selected as model pollutants to study the performance of β-CDP and three kinds of commercial adsorbents, including granular activated carbon, DARCO-AC, and two resins, XAD-4 and D-201, were used for comparison. The polymer shows ultrarapid adsorption kinetics for the removal of these pollutants, with pseudo-second-order rate constants two to three orders of magnitude higher than that of the commercial activated carbon and resins. Due to the different adsorption sites of NOM and OMPs, β-CDP can simultaneously remove these pollutants without competitive adsorption. The maximum adsorption capacity of β-CDP for HA, FA, 2-NO, 3-PH, 2,4,6-TCP, BPA, and BPS based on the Langmuir model is 40, 166, 74, 101, 108, 103, and 117 mg g^-1, respectively. After use, the polymer can be easily regenerated at room temperature. In addition, β-CDP also showed excellent bactericidal properties due to the quaternary ammonium groups. At a concentration of 15 g L^-1, β-CDP can remove 98% of the tested Escherichia coli. Moreover, the synthesis of β-CDP is simple, green, and easy to industrialize. All of these findings indicate that β-CDP, as an ideal multifunctional material, presents potential for practical applications for water treatment and disinfection.

Construction of β-Cyclodextrin Covalent Organic Framework-Modified Chiral Stationary Phase for Chiral Separation

Chiral covalent organic frameworks (CCOFs), built by the condensation reactions of organic building blocks with enantiomeric purity and linking subunits, have emerged as a marvelous category of porous crystalline material. In addition to stability and good porosity, CCOFs possess remarkable enantioselectivity, which would be exploited for asymmetric catalysis and chiral separation. β-cyclodextrin (β-CD) and its derivatives, a group of supramolecules with a hydrophobic cavity, have been widely applied to molecular specific recognitions. In this work, the β-CD covalent organic framework (COF) was exploited to construct chiral stationary phase (CSP) for chiral drugs analysis for the first time. We fabricated β-CD COF via the condensation reaction of heptakis(6-amino-6-deoxy)-β-CD and terephthalaldehyde at room temperature. β-CD COF-modified capillary columns were subsequently prepared by a photopolymerization method with shortened time and applied for separation of chiral drugs on capillary electrochromatography with good resolution and repeatability. Baseline separation for six enantiomers was achieved and the precisions (relative standard deviations) for intraday, interday, and column-to-column were <2.1%, 4.5%, and 7.3%, respectively. The results reveal that CCOFs-coated capillary columns show great prospect for chromatographic separation of chiral drugs.

Effect of inclusion complexation of meloxicam with β-cyclodextrin- and β-cyclodextrin-based nanosponges on solubility, in vitro release and stability studies

The objective of the present work was to develop inclusion complexes of meloxicam with β-cyclodextrin- and β-cyclodextrin-based nanosponges to enhance their solubility and stability and to prolong release using different methods that included physical mixing, kneading and sonication. Particle size, zeta potential, encapsulation efficiency, stability study results, in vitro and in vivo drug release study results, FTIR, DSC and XRPD were used as characterization parameters. SEM (Scanning Electron Microscope) studies revealed that the particle sizes of the inclusion complexes of meloxicam were within the range of 350 ± 5.69-765 ± 13.29 nm. The zeta potentials were sufficiently high to obtain stable formulations. In vitro and in vivo release studies revealed the controlled release of meloxicam from the nanosponges for 24h. The interaction of the meloxicam with the nanosponges was confirmed by FTIR and DSC. A XRPD study revealed that the crystalline nature of meloxicam was changed to an amorphous form due to the complexation with the nanosponges. A stability study revealed that the meloxicam nanosponges were stable. Therefore, β-cyclodextrin-based nanosponges represent a novel approach for the controlled release of meloxicam for anti-inflammatory and analgesic effects.

Beta-cyclodextrin complexes of celecoxib: molecular-modeling, characterization, and dissolution studies

Celecoxib, a specific inhibitor of cycloxygenase-2 (COX-2) is a poorly water-soluble nonsteroidal anti-inflammatory drug with relatively low bioavailability. The effect of beta-cyclodextrin on the aqueous solubility and dissolution rate of celecoxib was investigated. The possibility of molecular arrangement of inclusion complexes of celecoxib and beta-cyclodextrin were studied using molecular modeling and structural designing. The results offer a better correlation in terms of orientation of celecoxib inside the cyclodextrin cavity. Phase-solubility profile indicated that the solubility of celecoxib was significantly increased in the presence of beta-cyclodextrin and was classified as A(L)-type, indicating the 1:1 stoichiometric inclusion complexes. Solid complexes prepared by freeze drying, evaporation, and kneading methods were characterized using differential scanning calorimetry, powder x-ray diffractometry, and scanning electron microscopy. In vitro studies showed that the solubility and dissolution rate of celecoxib were significantly improved by complexation with beta-cyclodextrin with respect to the drug alone. In contrast, freeze-dried complexes showed higher dissolution rate than the other complexes.

Rapid elimination of trace bisphenol pollutants with porous β-cyclodextrin modified cellulose nanofibrous membrane in water: adsorption behavior and mechanism

A porous β-cyclodextrin modified cellulose nano-fiber membrane (CA-P-CDP) was fabricated and employed to treat the trace bisphenol pollutants (bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF)) in water. The characterization highlighted the porous structure, stable crystal structure, good thermal stability of the obtained CA-P-CDP, as well as abundant functional groups, which could greatly improve the adsorption of bisphenol pollutants and recovery. During the static adsorption process, the adsorbents dosage, temperature and pH showed significant influence on the adsorption performance. At the selected conditions (25 °C, 7.0 of pH and 0.1 g L^-1 of CA-P-CDP dosage), the BPA/BPS/BPF adsorption on CA-P-CDP could rapidly reached the equilibrium in 15 min by following the pseudo-second-order kinetic model, and the maximum adsorption capacities were 50.37, 48.52 and 47.25 mg g^-1, respectively, according to Liu isotherm model. The mechanisms between the bisphenol pollutants and CA-P-CDP mainly involved the synergism of hydrophobic effects, hydrogen-bonding interactions and π-π stacking interactions. Besides, the dynamic adsorption data showed that the volume of treated water for CA-P-CDP (0.58 L) was 14.5 times larger than that of pristine cellulose membrane (0.04 L), revealing satisfactory adsorption performance of trace BPA in water. Furthermore, during the treatment of real water samples (lake water and river water) with trace bisphenol pollutants, the complete removal of the pollutants were evidently observed, which strongly verified the possibility of CA-P-CDP for the practical application.

Heparin-mimicking multilayer coating on polymeric membrane via LbL assembly of cyclodextrin-based supramolecules

In this study, multifunctional and heparin-mimicking star-shaped supramolecules-deposited 3D porous multilayer films with improved biocompatibility were fabricated via a layer-by-layer (LbL) self-assembly method on polymeric membrane substrates. Star-shaped heparin-mimicking polyanions (including poly(styrenesulfonate-co-sodium acrylate; Star-PSS-AANa) and poly(styrenesulfonate-co-poly(ethylene glycol)methyl ether methacrylate; Star-PSS-EGMA)) and polycations (poly(methyl chloride-quaternized 2-(dimethylamino)ethyl methacrylate; Star-PMeDMA) were first synthesized by atom transfer radical polymerization (ATRP) from β-cyclodextrin (β-CD) based cores. Then assembly of 3D porous multilayers onto polymeric membrane surfaces was carried out by alternating deposition of the polyanions and polycations via electrostatic interaction. The surface morphology and composition, water contact angle, blood activation, and thrombotic potential as well as cell viability for the coated heparin-mimicking films were systematically investigated. The results of surface ATR-FTIR spectra and XPS spectra verified successful deposition of the star-shaped supramolecules onto the biomedical membrane surfaces; scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations revealed that the modified substrate had 3D porous surface morphology, which might have a great biological influence on the biointerface. Furthermore, systematic in vitro investigation of protein adsorption, platelet adhesion, human platelet factor 4 (PF4, indicates platelet activation), activate partial thromboplastin time (APTT), thrombin time (TT), coagulation activation (thrombin-antithrombin III complex (TAT, indicates blood coagulant)), and blood-related complement activation (C3a and C5a, indicates inflammation potential) confirmed that the heparin-mimicking multilayer coated membranes exhibited ultralow blood component activations and excellent hemocompatibility. Meanwhile, after surface coating, endothelial cell viability was also promoted, which indicated that the heparin-mimicking multilayer coating might extend the application fields of polymeric membranes in biomedical fields.

Preparation and Characterization of a Modified-β-Cyclodextrin/β-Carotene Inclusion Complex and Its Application in Pickering Emulsions

β-Cyclodextrin (β-CD) was modified using octenyl succinic anhydride (OSA) to introduce amphiphilic groups (hydrophilic carboxyl and lipophilic octenyl chains) by esterification under alkaline conditions. The FT-IR results indicated that the OSA-modified β-CD (OCD) showed new absorption peaks of an ester bond and a carboxylate (RCOO^-) at 1724 and 1570 cm^-1, respectively, confirming the successful preparation of OCD. Then the embedding effects of β-CD and OCD on β-carotene and the emulsifying and antioxidant properties of their inclusion complexes were evaluated. The results of XRD showed that the β-CD (or OCD)/β-carotene inclusion complexes were converted from a cage-type structure to a channel-type structure. AFM and SEM showed that the crystal characteristics and surface morphologies of the inclusion complexes were different from those of the physical mixture. The emulsion stabilized by OCD exhibited smaller droplet sizes and larger zeta-potentials than that stabilized by β-CD. In addition, the inclusion complexes-prepared emulsion exhibited lower POV values and TBARS contents than did the physical mixture. OCD/β-carotene inclusion complexes can improve the physical and oxidative stability of the emulsion, which is of great significance to the food industry.

Preparation and Evaluation of Silymarin β-cyclodextrin Molecular Inclusion Complexes

Silymarin is a hepatoprotective agent, having poor water solubility and oral absorption of about 23 – 47%, leading to low bioavailability of the drug. The aim of the present study is to improve the solubility and dissolution rate and in turn the hepatoprotective activity of the drug, by formulating its inclusion complex with beta (β)-cyclodextrin, using different methods. The phase solubility analysis indicates the formation of 1:1 molar inclusion complex of the drug with beta cyclodextrin. Apparent stability constant for Silymarin (K_c) was 722 K^-1 with β-cyclodextrin complex. The inclusion complexes were prepared by four different methods, namely, physical mixing, kneading, co-precipitation, and solvent evaporation. The prepared complexes were characterized using differential scanning colorimetry, scanning electron microscopy, and x-ray diffractometry. The inclusion complex prepared by the co-precipitation methods exhibits an overall best result, with respect to the formulation of sustained release formulations.

High-Capacity Amidoxime-Functionalized β-Cyclodextrin/Graphene Aerogel for Selective Uranium Capture

Uranium extraction from seawater is a grand challenge of mounting severity as the energy demand increases with a growing global population. An amidoxime-functionalized carboxymethyl β-cyclodextrin/graphene aerogel (GDC) is developed for highly efficient and selective uranium extraction via a facile one-pot hydrothermal process. GDC reaches equilibrium in 1 h, and the maximum adsorption capacity calculated from Langmuir model is 654.2 mg/g. Benefiting from the chelation and complexation reaction, the obtained GDC has an excellent selectivity even when the competitive cations, anions, and oil pollutants exist. In addition, the aerogel possesses great mechanical integrity and remains intact after 10 compression cycles. Meanwhile, the GDC can be easily regenerated and maintains a high reusability of 87.3% after 10 adsorption-desorption cycles. It is worthwhile to mention that GDC exhibits an excellent extraction capacity of 19.7 mg/g within 21 days in natural seawater, which is greatly desired in uranium extraction from seawater.

Modulation of Cyclodextrin Particle Amphiphilic Properties to Stabilize Pickering Emulsion

Cyclodextrins have been proven to form complexes with linear oil molecules and stabilize emulsions. Amphiphilic properties of cyclodextrin particles were modulated through esterification reaction between β-cyclodextrin (β-CD) and octadecenyl succinic anhydride (ODSA) under alkaline conditions. ODS-β-CD particles with degree of substitution (DS) of 0.003, 0.011, and 0.019 were obtained. The introduced hydrophobic long chain that was linked within β-CD cavity led to the change of ODS-β-CD in terms of morphological structure, surface charge density, size, and contact angle, upon which the properties and stability of the emulsions stabilized by ODS-β-CD were highly dependent. The average diameter of ODS-β-CD particles ranged from 449 to 1484 nm. With the DS increased from 0.003 to 0.019, the contact angle and absolute zeta potential value of these ODS-β-CD particles improved from 25.7° to 47.3° and 48.1 to 62.8 mV, respectively. The cage structure of β-CD crystals was transformed to channel structure, then further to amorphous structure after introduction of the octadecenyl succinylation chain. ODS-β-CD particles exhibited higher emulsifying ability compared to β-CD. The resulting Pickering emulsions formed by ODS-β-CD particles were more stable during storage. This study investigates the ability of these ODS-β-CD particles to stabilize oil-in-water emulsions with respect to their amphiphilic character and structural properties.

Electrochemical aptasensor for aflatoxin B1 based on smart host-guest recognition of β-cyclodextrin polymer

Developing a simple and reliable method for the detection of the highly concerning mycotoxin, aflatoxin B1 (AFB1), is of great importance to food safety monitoring. In this study, a simple electrochemical aptasensor was presented for the detection of AFB1 based on the host-guest recognition between ferrocene and β-cyclodextrin (β-CD). Fc-labeled aptamer of AFB1 first hybridized with its complementary Fc-cDNA. Two ferrocene molecules were brought closely together and couldn't enter into the cavity of β-CD modified on the electrode. Negligible signal could be observed. Once AFB1 captured the aptamer from the AFB1-sensitive dsDNA, Fc-cDNA was released and subsequently entered into the cavity of β-CD to form inclusion complexes, giving rise to an distinct increase of R_et and peak current because of the molecular recognition of β-CD. AC impedance method is more sensitive than DPV method. The electrochemical aptasensor displayed a sensitive response to AFB1 in a wide linear range of 0.1 pg/mL to 10 ng/mL, with a low detection limit of 0.049 pg/mL (0.147 pmol/mL) by AC impedance detection, which is 10-100 lower than previously reported methods. The aptasensor has good selectivity and reliability, which has been successfully applied to the determination of AFB1 in real peanut oil samples with recoveries ranging from 94.5% to 106.7% and inter-assay RSD lower than 11.51%.

A versatile β-cyclodextrin and polyethyleneimine bi-functionalized magnetic nanoadsorbent for simultaneous capture of methyl orange and Pb(II) from complex wastewater

Ascribing to their significant differences in physicochemical properties, it is extremely challenging to treat complex wastewater containing more than one class of pollutants via one-step treatment. Here, we focused on disposal of complex wastewater bearing organic dye and heavy metal by using adsorptive method. Thus, by combining the advantages of polyethyleneimine (PEI), β-cyclodextrin (β-CD) as well as Fe₃O₄ magnetic nanoparticles, a versatile β-CD and PEI bi-functionalized magnetic nanoadsorbent (Fe₃O₄-PEI/β-CD) with spatially separated sorption sites was successfully constructed for simultaneous capture of methyl orange (MO) and Pb(II) in complex wastewater. In this setting, β-CD cavities and positively charged N-containing groups of PEI were mainly responsible for removal of MO via host-guest inclusion and electrostatic attraction, respectively, and oxygen-bearing groups on the edge of β-CD as well as the free amino moieties in PEI acted as the active sites for Pb(II) uptake. In their individual mono-pollutant system, the adsorption processes can be better described via applying pseudo-second-order kinetic and Langmuir isotherm models. Interestingly, presence of MO in Pb(II)-MO binary system significantly promoted the uptake of Pb(II). But the coexisting Pb(II) had almost no effects on MO uptake. Such results demonstrated that both MO and Pb(II) could be simultaneously and synergistically removed by Fe₃O₄-PEI/β-CD through multiple mechanisms (such as electrostatic attraction, host-guest inclusion, chelating, etc.). Particularly, the excellent regeneration and stability make Fe₃O₄-PEI/β-CD an ideal integrative adsorbent for purification of actual wastewater contaminated by MO and Pb(II). Thus, this study provides some insights into designing a well-performed and easily recyclable adsorbent for simultaneous and synergetic capture of both organic and inorganic contaminants in complex wastewater.

Encapsulation of Oregano (Origanum onites L.) Essential Oil in β-Cyclodextrin (β-CD): Synthesis and Characterization of the Inclusion Complexes

The aim of the present work was to study the encapsulation of Origanum onites L. essential oil (oregano EO) in β-cyclodextrin (β-CD) inclusion complexes (ICs), using the co-precipitation method. The formed β-CD-oregano EO ICs were characterized by diverse methods, such as Dynamic Light Scattering (DLS), FT-IR spectroscopy, Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Nuclear Magnetic Resonance (NMR) spectroscopy and Scanning Electron Microscopy (SEM). UV-Vis spectroscopy was used for the determination of the inclusion efficacy and the study of the encapsulated oregano EO release profile. The interactions between host (β-CD) and guest (oregano EO) in the formed ICs were proven by the FT-IR, DSC, TG and NMR analyses. The ICs, which derived from different batches, presented nanoscale size (531.8 ± 7.7 nm and 450.3 ± 11.5 nm, respectively), good size dispersion (0.308 ± 0.062 and 0.484 ± 0.029, respectively) and satisfactory stability in suspension (ζ-potential = -21.5 ± 1.2 mV and -30.7 ± 1.8 mV). Inclusion efficiency reached up to 26%, whereas the oregano EO release from the ICs followed a continuous delivery profile for up to 11 days, based on in vitro experiments. The formed ICs can find diverse applications, such as in the preparation of films for active packaging of food products, in personal care products for the improvement of their properties (e.g., antioxidant, antimicrobial, etc.), as well as in insect repellent products.

Efficient Graphene/Cyclodextrin-Based Nanocontainer: Synthesis and Host-Guest Inclusion for Self-Healing Anticorrosion Application

Cyclodextrin, with a hydrophobic inner cavity and a hydrophilic exterior, is often used to encapsulate a widest range of guest molecules based on host-guest inclusion interactions. Graphene, an emerging nanobuilding material, exhibits great potential for numerous applications because of its superior characteristics. Herein, we synthesized a novel graphene/β-cyclodextrin-based supramolecular nanocontainer with excellent inhibitor encapsulating capacity and high impermeable properties. The benzotriazole (BTA)-loaded nanocontainers were then used to endow coating system with excellent passive and active anticorrosion performance. Local electrochemical impedance spectroscopy (LEIS) was performed to characterize the self-healing behavior of composite coatings. Results indicated that the protective capability of the scratched coatings can be recovered through BTA release from containers. Furthermore, the long-term corrosion resistance of container-based coating was largely improved as observed from EIS. The effective healing process involves two conditions: (1) the release of BTA from containers and formation of adsorption layers on exposed metal surfaces and (2) the impermeable graphene nanosheets greatly impeded the electrolyte penetration and corrosion extension around the scratch. This novel graphene/β-cyclodextrin-based nanocontainer endows polymer coating with efficient self-healing functionality and durable anticorrosion property.

Host-Guest Self-Assembly Toward Reversible Thermoresponsive Switching for Bacteria Killing and Detachment

A facile method to construct reversible thermoresponsive switching for bacteria killing and detachment was currently developed by host-guest self-assembly of β-cyclodextrin (β-CD) and adamantane (Ad). Ad-terminated poly(N-isopropylacrylamide) (Ad-PNIPAM) and Ad-terminated poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (Ad-PMT) were synthesized via atom transfer radical polymerization, and then assembled onto the surface of β-CD grafted silicon wafer (SW-CD) by simply immersing SW-CD into a mixed solution of Ad-PNIPAM and Ad-PMT, thus forming a thermoresponsive surface (SW-PNIPAM/PMT). Atomic force microscopy (AFM), X-ray photoelectron spectrometry (XPS), and water contact angle (WCA) analysis were used to characterize the surface of SW-PNIPAM/PMT. The thermoresponsive bacteria killing and detachment switch of the SW-PNIPAM/PMT was investigated against Staphyloccocus aureus. The microbiological experiments confirmed the efficient bacteria killing and detachment switch across the lower critical solution temperature (LCST) of PNIPAM. Above the LCST, the Ad-PNIPAM chains on the SW-PNIPAM/PMT surface were collapsed to expose Ad-PMT chains, and then the exposed Ad-PMT would kill the attached bacteria. While below the LCST, the previously collapsed Ad-PNIPAM chains became more hydrophilic and swelled to cover the Ad-PMT chains, leading to the detachment of bacterial debris. Besides, the proposed method to fabricate stimuli-responsive surfaces with reversible switches for bacteria killing and detachment is facile and efficient, which creates a new route to extend the application of such smart surfaces in the fields requiring long-term antimicrobial treatment.

Cyclodextrin functionalized agarose gel with low gelling temperature for controlled drug delivery systems

Conventional agaroses with high gelling temperature are limited to apply to the field of drug delivery. In this study, β-cyclodextrin (βCD) functionalized agarose (CFA) with low gelling temperature was successfully prepared from ethylenediamine-functionalized agarose using mono-succinyl βCD. The gelling temperature of CFA dramatically decreased to 26.7 °C from 65 °C and the melting temperature declined from 95 °C to 66.1 °C. Upon drug loading, CFA can be used at 30 °C because of its low gelling temperature compared to agarose. CFA gel could be used both for bovine serum albumin as a full release, and for the doxorubicin (DOX) for sustained release, via inclusion complexation of βCD. Furthermore, cytotoxicity tests revealed that CFA was noncytotoxic. DOX in the CFA gel could retain the anti-cancer activity. Newly synthesized CFA with low gelling temperature offer a new means for the development of hydrogel-based delivery systems for a variety of therapeutic drugs.

Extraction of red beet extract with β-cyclodextrin-enhanced ultrasound assisted extraction: A strategy for enhancing the extraction efficacy of bioactive compounds and their stability in food models

Improving the extraction efficiency and stability of red beet compounds has gained the attention of researchers due to their high nutritional and health benefits. In this study, β-cyclodextrin (β-CD) enhanced ultrasound assisted extraction was used for the extraction of red beet extract, and lyophilized extracts were characterized with FTIR and DSC analyses. The samples extracted with aqueous 5% β-CD solutions revealed the highest content of betanin (2.243 ± 0.04 mg) and total phenolic compounds (20.03 ± 1.28 mg GAE/g DW), and the highest DPPH inhibition activity (59.87 ± 4.94%). Additionally, complexation with β-CD significantly enhanced the stability of betanin, phenolic compounds and antiradical activity in the stored beverage and gummy candy models at various pH and temperature conditions during 28 days. In conclusion, β-CD-enhanced ultrasound assisted extraction is a suitable approach to extracting and stabilizing the red beet compounds for application in food, nutraceutical, and medical fields.

Surface modification of graphene oxide with stimuli-responsive polymer brush containing β-cyclodextrin as a pendant group: Preparation, characterization, and evaluation as controlled drug delivery agent

In this work, stimuli-responsive graphene oxide/polymer brush nanocomposites (GPBNs) prepared through the polymerization of acrylic acid (AA), N-isopropylacrylamide (NIPAM) and acrylated β-cyclodextrin (Ac-β-CD) from the graphene oxide (GO) surface. The attachment of polymers on the GO surface was approved using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV-vis spectroscopy (UV-vis) and thermogravimetric (TGA) analysis. Scanning electron microscopy (SEM) was used to observe the morphological change on the GO surface after polymer grafting. Transition electron microscopy (TEM) showed that polymeric brushes were decorated on the GO surface. The growth of polymer brushes on the GO was further confirmed using atomic force microscopy (AFM). Both hydrophilic (doxorubicin, DOX) and hydrophobic (Methotrexate MTX) drugs were co-loaded in the prepared graphene Oxide/Polyacrylated β-cyclodextrin/polyacrylic acid/poly N-isopropylacrylamide brush nanocomposite (GCANBN). Drug releases from GCANBN were studied using UV-vis. MTT assay was used for the evaluation of in-vitro cytotoxicity of GCANBN. The prepared system showed its efficacy as a nanocarrier for both types of drugs.

Novel molecularly imprinted polymer based on β-cyclodextrin@graphene oxide: Synthesis and application for selective diphenylamine determination

A sensitive and selective molecularly imprinted polymer (MIP) for the determination of diphenylamine (DPA) was developed based on host-guest interactions of a cyclodextrin-based polymer which possesses an inherent affinity for the target. The proposed GO@MIP has been prepared using the graphene oxide (GO) sheets as surface of polymerization, DPA as target molecule, β-cyclodextrin (β-CD) and acrylamide (AM) as functional monomers, azobisisobutyronitrile (AIBN) as initiator and N, N methylene bisacrylamide (MBAm) as crosslinker which denoted as GO@MIP nanocomposite. The MIP sites were formed by the inclusion complex through interaction of DPA and β-CD, followed by extraction of target. The resulting GO@MIP nanocomposite possess a fast adsorption kinetics, highly improved imprinting effect, high adsorption capacity, and it can be applied to fast extraction of DPA. The resultant GO@MIP nanocomposite was characterized using the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) analysis. On the other hand, the non-imprinted polymer (GO@NIP nanocomposite) has been synthesized and was used in the adsorption experiments. The MIP exhibited good affinity with a maximum adsorption capacity of 95.98mgg^-1 and excellent selectivity toward DPA than other structural analogues such as 2-amino benzophenone and dithizone.

Facile construction of shape-regulated β-cyclodextrin-based supramolecular self-assemblies for drug delivery

Although supramolecular prodrug self-assemblies have been proven as efficient nanocarriers for cancer therapy, tedious synthesis procedures have made their practical applications more difficult. In this paper, β-cyclodextrin-based supramolecular self-assemblies (SSAs) were directly constructed by utilizing β-cyclodextrin trimer (β-CD₃) as the host unit and unmodified curcumin as the guest unit. Due to the adjustment of host-guest inclusion and hydrophilic-hydrophobic interactions occurring in the SSAs, their morphology could be readily tuned by changing the ratio of the two components. Different self-assembly morphologies, such as spherical complex micelles, spindle-like complex micelles and multi-compartment vesicles, were obtained. Furthermore, basic cell experiments were performed to study the corresponding effects of the SSA shape on their biological properties. Compared to the other micelles, the spindle-like complex micelles exhibited enhanced cellular toxicity, uptake behaviors and apoptosis rates, and the spherical complex micelles exhibited poor performance. The performance of the multi-compartment vesicles was similar to that of the spindle-like complex micelles. The facile construction of these shape-regulated SSAs and their different cellular biological properties might be valuable in the controlled drug release field.

Sugar-appended polyamidoamine dendrimer conjugates with cyclodextrins as cell-specific non-viral vectors

The widespread use of various cyclodextrin (CyD)-appended polymers and polyrotaxanes as gene carriers has been reported. Among the various polyamidoamine dendrimer (dendrimer) conjugates with CyDs (CDE), the dendrimer (G3) conjugate with α-CyD having an average degree of substitution (DS) of 2.4 (α-CDE (G3, DS 2)) displayed remarkable properties as DNA carriers. In an attempt to develop cell-specific gene transfer carriers, we prepared some sugar-appended α-CDEs, e.g. mannosylated, galactosylated, and lactosylated α-CDEs. In addition, PEGylated Lac-α-CDEs (G3) were prepared and evaluated as a hepatocyte-selective and serum-resistant gene transfer carrier. Moreover, PEGylated-α-CDE/CyD polypseudorotaxane systems for novel sustained DNA release system have been developed. Interestingly, glucronylglucosyl-β-cyclodextrin (GUG-β-CyD) conjugates with dendrimer (G2) (GUG-β-CDE (G2)) had superior gene transfer activity to α-CDE (G2), expecting a development of new series of sugar-appended CDEs over α-CDEs (G2). Collectively, sugar-appended α-CDEs have the potential as novel cell-specific and safe carriers for DNA.