Biofunctionalization of β-cyclodextrin nanosponges using cholesterol

Sulphated zirconia on cyclodextrin nanosponge: A carbohydrate-based catalyst for conversion of mono-saccharides to 5-hydroxymethylfurfural

To expand the utility of cyclodextrin nanosponges for catalytic purpose, β-cyclodextrin nanosponge was prepared via melting method and then utilized as a catalyst support for the stabilization of sulphated zirconia. The resulting catalyst, denoted as CDNS-SO42-/ZrO2, was then applied as a heterogeneous acidic catalyst for conversion of fructose to 5-hydroxymethylfurfural. The results, underpinned that the catalytic activity of CDNS-SO42-/ZrO2, was superior to that of ZrO2 and SO42-/ZrO2, confirming the role of sulfonation of ZrO2 and immobilization of SO42-/ZrO2 on CDNS in catalysis. To optimize the reaction parameters and achieve maximum yield of the desired product, Response Surface Method that is an accurate procedure for appraising the impacts of the reaction variables was employed and it was found that using 35 wt% CDNS-SO42-/ZrO2 at 80 °C, HMF in 93 % yield was achieved in 45 min. Kinetic study also showed that the activation energy was 13.28 kJ/mol. Furthermore, thermodynamic parameters, i.e. enthalpy, entropy and Gibbs free energy were estimated as 10.46 kJ/mol, -150.40 J/mol and 63.58 kJ/mol respectively. Noteworthy, the catalysis was true heterogeneous, as confirmed by Hot filtration test and the catalyst could be recycled several times with low leaching of SO42-/ZrO2.

Leveraging Cholesterol-Functionalized Cyclodextrin Nanosponges for Enhanced Drug Delivery in Cancer Cells

Cholesterol, the essential building block of cellular membranes, has proven to be a useful tool for increasing the biocompatibility and bioavailability of drug delivery systems in cancer treatment. Resveratrol, a natural polyphenolic compound with promising anticancer properties, faces significant limitations due to its low solubility and bioavailability, hindering its clinical utility. Therefore, in the present study, we aimed to design cholesterol-functionalized cyclodextrin nanosponges (Chol-NSs) with a tunable cholesterol content to optimize resveratrol encapsulation and delivery. Both formulations, free carbonyl diimidazole (CDI) NSs and functionalized Chol-NSs, demonstrated high drug loading and encapsulation efficiency. In vitro experiments revealed that cholesterol incorporation significantly improved the cellular uptake of nanocarriers and potentiated the cytotoxic effects of resveratrol on breast cancer cells. Importantly, both free CDI NSs and functionalized Chol-NSs, even at varying cholesterol percentages, demonstrated a safe profile against both fibroblast and breast cancer cell lines. These results indicate that cholesterol-functionalized nanosponges represent a promising platform for the effective and safe delivery of natural compounds in cancer therapy.

Intelligent Reconfiguration-Promoted Cellular Internalization of Core-Shell DNA Nanoprobe Equipped with Successive Dual Stimuli-Responsive Protective Satellites for Amplification Fluorescence Imaging of Tumor Cells

Although DNA probes have attracted increasing interest for precise tumor cell identification by imaging intracellular biomarkers, the requirement of commercial transfection reagents, limited targeting ligands, and/or non-biocompatible inorganic nanostructures has hampered the clinic translation. To circumvent these shortcomings, a reconfigurable ES-NC (Na+-dependent DNAzyme (E)-based substrate (S) cleavage core/shell DNA nanocluster (NC)) entirely from DNA strands is assembled for precise imaging of cancerous cells in a successive dual-stimuli-responsive manner. This nanoprobe is composed of a strung DNA tetrahedral satellites-based protective (DTP) shell, parallelly aligned target-responsive sensing (PTS) interlayer, and hydrophobic cholesterol-packed innermost layer (HCI core). Tetrahedral axial rotation-activated reconfiguration of DTP shell promotes the exposure of interior hydrophobic moieties, enabling cholesterol-mediated cellular internalization without auxiliary elements. Within cells, over-expressed glutathione triggers the disassembly of the DTP protective shell (first stimulus), facilitating target-stimulated signal transduction/amplification process (second stimuli). Target miRNA-21 is detected down to 10.6 fM without interference from coexisting miRNAs. Compared with transfection reagent-mediated counterpart, ES-NC displays a higher imaging ability, resists nuclease degradation, and has no detectable damage to healthy cells. The blind test demonstrates that the ES-NC is suitable for the identification of cancerous cells from healthy cells, indicating a promising tool for early diagnosis and prediction of cancer.

Vertical porous aerogel based on polypyrrole and bimetallic modified β-cyclodextrin polymer-chitosan for efficient solar evaporation

Solar-driven interfacial evaporation (SDIE) stands out as a prospective technology for freshwater production, playing a significant role in mitigating global water scarcity. Herein, a cyclodextrin polymer/chitosan composite aerogel (PPy-La/Al@CDP-CS) with vertically aligned channels was prepared as a solar evaporator for efficient solar steam generation. The vertically aligned pore structure, achieved through directional freezing assisted by liquid nitrogen, not only improves water transport during evaporation but also enhances light absorption through multiple reflections of sunlight within the pores. The polypyrrole particles sprayed on the surface of the aerogel acted as a light-absorbing layer, resulting in an impressive absorbance of 98.15 % under wetting conditions. The aerogel has an evaporation rate of 1.85 kg m-2 h-1 under 1 kW m-2 irradiation. Notably, the vertical pore structure of the aerogel allows it to exhibit excellent evaporation performance and salt resistance even in highly concentrated salt solutions. Furthermore, this aerogel is an excellent solar-driven interfacial evaporator for purifying seawater and fluoride-containing wastewater. This photothermal aerogel has the advantages of excellent performance, low cost, and environmental friendliness, and thus this work provides a new approach to the design and fabrication of solar photothermal materials for water treatment.

Dispersive solid phase extraction based on cross-linked hydroxypropyl β-cyclodextrin polymers for simultaneous enantiomeric determination of three chiral triazole fungicides in water

An efficient method is presented for simultaneous enantioselective determination of three chiral triazole fungicides (namely paclobutrazol, hexaconazole, and diniconazole) in water samples by DSPE-HPLC-UV. The perfect chiral separation of the enantiomers was achieved on a Chiralpak IH column within 15 min. In order to adsorb and enrich the analytes from water matrices, a cross-linked hydroxypropyl β-cyclodextrin polymer was synthesized. The prepared material exhibited good adsorption capacity, which was assessed by adsorption kinetic and adsorption thermodynamic experiments. One-variable-at-a-time and the response surface methodology were used to optimize the extraction parameters. Under the optimum sample preparation conditions, good linearity (2.0 ~ 800 µg L-1, R2 ≥ 0.9978), detection limits (0.6 to 1.0 µg L-1), quantitation limits (2.0 to 3.2 µg L-1), recoveries (86.7 ~ 105.8%), and the relative standard deviation (intra-day RSD ≤ 3.7%, inter-day RSD ≤ 5.1%) were obtained, satisfying the requirements of pesticides residues determination. These results demonstrated that the proposed method was applicable for routine determination of chiral triazole fungicide residues in water samples.

β-Cyclodextrin Nanosponges Inclusion Compounds Associated with Silver Nanoparticles to Increase the Antimicrobial Activity of Quercetin

This work aimed to synthesize and characterize a nanocarrier that consisted of a ternary system, namely β-cyclodextrin-based nanosponge (NS) inclusion compounds (ICs) associated with silver nanoparticles (AgNPs) to increase the antimicrobial activity of quercetin (QRC). The nanosystem was developed to overcome the therapeutical limitations of QRC. The host-guest interaction between NSs and QRC was confirmed by field emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRPD), thermogravimetric analysis (TGA), and proton nuclear magnetic resonance (¹H-NMR). Moreover, the association of AgNPs with the NS-QRC was characterized using FE-SEM, energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), dynamic light scattering (DLS), ζ-potential, and UV-Vis. Finally, the antimicrobial activity of the novel formulations was tested, which depicted that the complexation of QRC inside the supramolecular interstices of NSs increases the inhibitory effects against Escherichia coli ATCC25922, as compared to that observed in the free QRC. In addition, at the same concentrations used to generate an antibacterial effect, the NS-QRC system with AgNPs does not affect the metabolic activity of GES-1 cells. Therefore, these results suggest that the use of NSs associated with AgNPs resulted in an efficient strategy to improve the physicochemical features of QRC.

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.

Nanosponges for Drug Delivery and Cancer Therapy: Recent Advances

Nanosponges with three-dimensional (3D) porous structures, narrow size distribution, and high entrapment efficiency are widely engineered for cancer therapy and drug delivery purposes. They protect the molecular agents from degradation and help to improve the solubility of lipophilic therapeutic agents/drugs with targeted delivery options in addition to being magnetized to attain suitable magnetic features. Nanosponge-based delivery systems have been applied for cancer therapy with high specificity, biocompatibility, degradability, and prolonged release behavior. In this context, the drug loading within nanosponges is influenced by the crystallization degree. Notably, 3D printing technologies can be applied for the development of novel nanosponge-based systems for biomedical applications. The impacts of polymers, cross-linkers, type of drugs, temperature, loading and mechanism of drug release, fabrication methods, and substitution degree ought to be analytically evaluated. Eco-friendly techniques for the manufacturing of nanosponges still need to be uncovered in addition to the existing methods, such as solvent techniques, ultrasound-assisted preparation, melting strategies, and emulsion solvent diffusion methods. Herein, the recent advancements associated with the drug delivery and cancer therapy potential of nanosponges (chiefly, cyclodextrin-based, DNAzyme, and ethylcellulose nanosponges) are deliberated, focusing on the important challenges and future perspectives.

Anchoring β-CD on simvastatin-loaded rHDL for selective cholesterol crystals dissolution and enhanced anti-inflammatory effects in macrophage/foam cells

Macrophage/foam cells and cholesterol crystals (CCs) have been regarded as the central triggers of maladaptive inflammation in atherosclerotic plaque. Despite the tremendous progress of recombinant high-density lipoprotein (rHDL) serving for targeted drug delivery to alleviate inflammation in macrophage/foam cells, the active attempt to modulate/improve its CCs dissolution capacity remains poorly explored. The untreated CCs can seriously aggravate inflammation and threaten plaque stability. Based on the superb ability of β-cyclodextrin (β-CD) to bind CCs and promote cholesterol efflux, simvastatin-loaded discoidal-rHDL (ST-d-rHDL) anchored with β-CD (βCD-ST-d-rHDL) was constructed. We verified that βCD-ST-d-rHDL specifically bound and dissolved CCs extracellularly and intracellularly. Furthermore, anchoring β-CD onto the surface of ST-d-rHDL enhanced its cholesterol removal ability in RAW 264.7 cell-derived foam cells characterized by accelerated cholesterol efflux, reduced intracellular lipid deposition, and improved cell membrane fluidity/permeability. Finally, βCD-ST-d-rHDL exerted efficient drug delivery and effective anti-inflammatory effects in macrophage/foam cells. Collectively, anchoring β-CD onto the surface of ST-d-rHDL for selective CCs dissolution, accelerated cholesterol efflux, and improved drug delivery represents an effective strategy to enhance anti-inflammatory effects for the therapy of atherosclerosis.

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.

Cyclodextrin-Based Nanosponges: Overview and Opportunities

Nanosponges are solid cross-linked polymeric nano-sized porous structures. This broad concept involves, among others, metal organic frameworks and hydrogels. The focus of this manuscript is on cyclodextrin-based nanosponges. Cyclodextrins are cyclic oligomers of glucose derived from starch. The combined external hydrophilicity with the internal hydrophobic surface constitute a unique "microenvironment", that confers cyclodextrins the peculiar ability to form inclusion host‒guest complexes with many hydrophobic substances. These complexes may impart beneficial modifications of the properties of guest molecules such as solubility enhancement and stabilization of labile guests. These properties complemented with the possibility of using different crosslinkers and high polymeric surface, make these sponges highly suitable for a large range of applications. Despite that, in the last 2 decades, cyclodextrin-based nanosponges have been developed for pharmaceutical and biomedical applications, taking advantage of the nontoxicity of cyclodextrins towards humans. This paper provides a critical and timely compilation of the contributions involving cyclodextrins nanosponges for those areas, but also paves the way for other important applications, including water and soil remediation and catalysis.

Facile synthesis of novel multifunctional β-cyclodextrin microporous organic network and application in efficient removal of bisphenol A from water

Here, a novel multifunctional β-cyclodextrin microporous organic network (CD-MON) has been successfully synthesized and used to remove bisphenol A (BPA) from water. The morphology and composition of the synthesized CD-MON were confirmed. The combination of hydrophobic interaction, π-π interaction inclusion mechanism and hydrogen bonding endowed CD-MON to exhibit superior adsorption capacity toward BPA. The adsorption kinetics and isotherms of BPA and other four model aromatic pollutants on CD-MON were studied. CD-MON could maintain adsorption efficiency toward BPA over wide pH ranges and without being affected by the ionic strengths, co-existing inorganic ions and humic acid. The optimal conditions and removal efficiency of BPA were screened by response surface analysis. In addition, nearly unchanged in the adsorption efficiency toward BPA was observed after five regeneration cycles on CD-MON. CD-MON can adsorb about 80% of five model aromatic pollutants from the water within 40 s in the flow-through experiments. This novel adsorbent gives great promise for practical wastewater remediation.

Modification of cyclodextrin and use in environmental applications

Water pollution, which has become a global problem in parallel with environmental pollution, is a problem that needs to be solved urgently, considering the gradual depletion of water resources. The inadequacy of the water treatment methods and the materials used somehow directed the researchers to look for dual character structures such as biocompatible and biodegradable β-cyclodextrin (β-CD). β-CD, which is normally insoluble in water, is used in demanding wastewater applications by being modified with the help of different agents to be water soluble or transformed into polymeric adsorbents as a result of co-polymerization via cross-linkers. In this way, in addition to the host-guest interactions offered by β-CD, secondary forces arising from these interactions provide advantages in terms of regeneration and reusability. However, the adsorption efficiency and synthesis steps need to be improved. Based on the current studies presented in this review, in which cross-linkers and modification methods are also mentioned, suggestions for novel synthesis methods of new-generation β-CD-based materials, criticisms, and recent methods of removal of micropollutants such as heavy metals, industrial dyes, harmful biomolecules, and pharmaceutics wastes are mentioned.

TPGS assists the percutaneous administration of curcumin and glycyrrhetinic acid coloaded functionalized ethosomes for the synergistic treatment of psoriasis

Combined therapy with anti-inflammatory drugs is preferred for the topical treatment of psoriasis, but the codelivery of drugs is restricted due to the lack of a suitable delivery system. Ethosomes with excellenttransdermal propertiesare perfect as carriers for hyperplastic skin. Therefore, glycyrrhetinic acid-D-α-tocopherol acid polyethylene glycol succinate (GA-TPGS) was synthesized, which prevented the inflammation and lipid peroxidation damage, thus effectively stabilizing the psoriasis. Then GA-TPGS was surface-modified on the curcumin (Cur) loaded ethosomes to construct curcumin-loaded GA-TPGS-modified multifunctional ethosomes (Cur@GA-TPGS-ES), exerting synergistic treatment for psoriasis. Using an interleukin-6-induced cell model, we found that Cur@GA-TPGS-ES displayed desirable suppression of inflammation response and oxidative stress damage. Compared with the ethanol solution, the percutaneous penetration rates of Cur and GA in Cur@GA-TPGS-ES were superior. In vivo microdialysis revealed similar results, suggesting an increase of transcutaneous absorption in Cur@GA-TPGS-ES. Fluorescence staining revealed that the cellular uptake and skin distribution were distinctly enhanced with the delivery by Cur@GA-TPGS-ES. After topical administration to imiquimod-induced psoriatic mice, the Cur@GA-TPGS-ES group showed powerful treatment from inflammatory infiltration inhibition of Cur, glucocorticoid-like effects of GA and anti-lipid peroxidation of TPGS. Overall, GA-TPGS mediated ethosomes possess more advantageous transdermal properties and synergistic antipsoriatic efficacy.

β-Cyclodextrin-grafted hyaluronic acid as a supramolecular polysaccharide carrier for cell-targeted drug delivery

β-Cyclodextrin (β-CD) was grafted onto hyaluronic acid (HA) in a single step to generate a supramolecular biopolymer (HA-β-CD) that was explored for targeted drug delivery applications. Along with its excellent biocompatibility, the prepared HA-β-CD exhibits not only exceptionally high loading capacity for the model drugs doxorubicin and Rhodamine B through the formation of inclusion complexes with the β-CD component, but also the capability of targeted drug delivery to cancerous cells with a high level of expression of CD44 receptors, attributable to its HA component. The polymer can release the drug under slightly acidic conditions. With all its attributes, HA-β-CD may be a promising cancer-cell-targeting drug carrier.

β-Cyclodextrin-Based Nanosponges Functionalized with Drugs and Gold Nanoparticles

Drugs are widely used as therapeutic agents; however, they may present some limitations. To overcome some of the therapeutic disadvantages of drugs, the use of β-cyclodextrin-based nanosponges (βCDNS) constitutes a promising strategy. βCDNS are matrices that contain multiple hydrophobic cavities, increasing the loading capacity, association, and stability of the included drugs. On the other hand, gold nanoparticles (AuNPs) are also used as therapeutic and diagnostic agents due to their unique properties and high chemical reactivity. In this work, we developed a new nanomaterial based on βCDNS and two therapeutic agents, drugs and AuNPs. First, the drugs phenylethylamine (PhEA) and 2-amino-4-(4-chlorophenyl)-thiazole (AT) were loaded on βCDNS. Later, the βCDNS-drug supramolecular complexes were functionalized with AuNPs, forming the βCDNS-PhEA-AuNP and βCDNS-AT-AuNP systems. The success of the formation of βCDNS and the loading of PhEA, AT, and AuNPs was demonstrated using different characterization techniques. The loading capacities of PhEA and AT in βCDNS were 90% and 150%, respectively, which is eight times higher than that with native βCD. The functional groups SH and NH2 of the drugs remained exposed and allowed the stabilization of the AuNPs, 85% of which were immobilized. These unique systems can be versatile materials with an efficient loading capacity for potential applications in the transport of therapeutic agents.

The Efficacy of Cholesterol-Based Carriers in Drug Delivery

Several researchers have reported the use of cholesterol-based carriers in drug delivery. The presence of cholesterol in cell membranes and its wide distribution in the body has led to it being used in preparing carriers for the delivery of a variety of therapeutic agents such as anticancer, antimalarials and antivirals. These cholesterol-based carriers were designed as micelles, nanoparticles, copolymers, liposomes, etc. and their routes of administration include oral, intravenous and transdermal. The biocompatibility, good bioavailability and biological activity of cholesterol-based carriers make them potent prodrugs. Several in vitro and in vivo studies revealed cholesterol-based carriers potentials in delivering bioactive agents. In this manuscript, a critical review of the efficacy of cholesterol-based carriers is reported.

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.

Evaluation of solubility enhancement, antioxidant activity, and cytotoxicity studies of kynurenic acid loaded cyclodextrin nanosponge

Kynurenic acid demonstrates antioxidant, neuroprotective and free radical scavenging properties. However, low aqueous solubility of kynurenic acid limits its therapeutic activity. In the present study, cyclodextrin nanosponges were used to improve the solubility and therapeutic activity of kynurenic acid. The formation of kynurenic acid loaded nanosponge was confirmed by different characterization techniques. The solubility of kynurenic acid was significantly increased with nanosponge (111.1 μg/ml) compared to free kynurenic acid (16.4 μg/ml) and β-cyclodextrin (28.6 μg/ml). High drug loading (19.06%) and encapsulation efficiency (95.31%) were achieved with NS. The particle size and zeta potential of kynurenic acid loaded nanosponge was around 255.8 nm and -23 mV respectively. Moreover, higher solubilization of kynurenic acid loaded nanosponge produced better antioxidant activity compared to free kynurenic acid. The kynurenic acid loaded nanosponge and blank nanosponge were found nontoxic in the cytotoxicity assay. Thus, these studies demonstrated that nanosponges can be used as a carrier for the delivery of kynurenic acid.

Injectable Cholesterol-Enhanced Stereocomplex Polylactide Thermogel Loading Chondrocytes for Optimized Cartilage Regeneration

Ideal cartilage tissue engineering requires scaffolds featuring good biocompatibility, large pore structure, high mechanical strength, as well as minimal invasion procedure. Although significant progress has been made in the development of polymer scaffolds, the construction of smart systems with all the desired properties is still emerging as a challenge. The thermogels of stereocomplex 4-arm poly(ethylene glycol)-polylactide (PEG-PLA) (scPLA_gel ) and stereocomplex cholesterol-modified 4-arm PEG-PLA (scPLA-Chol_gel ) from the equimolar enantiomeric 4-arm PEG-PLA and 4-arm PEG-PLA-Chol, respectively, are fabricated as scaffolds for cartilage tissue engineering. scPLA-Chol_gel shows lower critical gelation temperature, higher mechanical strength, larger pore size, better chondrocyte adhesion, and slower degradation compared to scPLA_gel as the benefit of cholesterol modification, which is more appropriate for cartilage regeneration. Moreover, the preservation of morphology, biomechanical property, cartilaginous specific matrix, as well as cartilaginous gene expressions of engineered cartilage mediated by scPLA-Chol_gel are proven superior to those by scPLA_gel . scPLA-Chol_gel serves as a promising chondrocyte carrier for cartilage tissue engineering and gives an alternative solution to clinical cartilage repair.

Cyclodextrin-based nanosponges as promising carriers for active agents

INTRODUCTION

In recent years, new drug delivery systems have attempted to overcome the undesirable pharmacokinetic problems of various drugs. Among them, cyclodextrin nanosponges (CDNSs) attract great attention from researchers for solving major bioavailability problems such as inadequate solubility, poor dissolution rate, and the limited stability of some agents, as well as increasing their effectiveness and decreasing unwanted side effects. This novel system can also be prepared as different dosage forms.

AREAS COVERED

This review will give an insight into the effects of CDNSs on the pharmacokinetic parameters and permeability of active agents. Different classes of drugs delivered by this system are mentioned and we designate which CD is used most widely in their production process. We also inform why this carrier can be introduced as a versatile carrying system in pharmaceutical fields. Registered patents about this novel system in various fields are also mentioned.

EXPERT OPINION

The readers will be informed on CDNSs as a novel carrier especially for the delivery of drugs. Versatile characteristics and applications of them can also be known by this review. Finally, CDNSs may be introduced as a remarkable vehicle in the pharmaceutical market in coming years.

Nano-scale polysaccharide materials in food and agricultural applications

Potential applications of nanotechnology in food and agriculture include: (1) the encapsulation of functional compounds; (2) production of reinforcing materials; (3) delivery of nutraceuticals in foods; (4) food safety, for detection and control of chemical and microbiological risks; (5) active and intelligent food packaging; (6) incorporation of protective substances of seeds; (7) addition of nutrients in the soil; (8) use of controlled release pesticides. Natural polysaccharides and their derivatives are widely used in the production of nano-scale materials. This chapter examines, the use of polysaccharides, such as starch, cellulose, lignin, pectin, gums, and cyclodextrins for the production of nano-scale materials, including nanocrystals, nanoemulsions, nanocomplexes, nanocapsules, and nanofibers.

Cholesterol-Based Compounds: Recent Advances in Synthesis and Applications

This review reports on the latest developments (since 2014) in the chemistry of cholesterol and its applications in different research fields. These applications range from drug delivery or bioimaging applications to cholesterol-based liquid crystals and gelators. A brief overview of the most recent synthetic procedures to obtain new cholesterol derivatives is also provided, as well as the latest anticancer, antimicrobial, and antioxidant new cholesterol-based derivatives. This review discusses not only the synthetic details of the preparation of new cholesterol derivatives or conjugates, but also gives a short summary concerning the specific application of such compounds.

Cyclodextrin based nanosponge of norfloxacin: Intestinal permeation enhancement and improved antibacterial activity

Nanosponges are a novel class of hyperbranched cyclodextrin-based nanostructures that exhibits remarkable potential as a drug host system for the improvement in biopharmaceutical properties. This work aims the development of cyclodextrin-based nanosponge of norfloxacin to improve its physicochemical characteristics. β-cyclodextrin was used as base and diphenyl carbonate as crosslinker agent at different proportions to produce nanosponges that were evaluated by in vitro and in vivo techniques. The proportion cyclodextrin:crosslinker 1:2 M/M was chosen due to its higher encapsulation efficiency (80%), revealing an average diameter size of 40 nm with zeta potential of -19 mV. Norfloxacin-loaded nanosponges exhibited higher passage of norfloxacin in comparison to norfloxacin drug alone by Ussing chamber method. The nanosponge formulation also revealed a mucoadhesive property that could increase norfloxacin absorption thus improving its antibiotic activity in an in vivo sepsis model. Therefore, nanosponges may be suitable carrier of norfloxacin to maximize and facilitate oral absorption.

Preparation and properties of nanocomposites of β-cyclodextrin-functionalized polyacrylamide and its application for enhancing oil recovery

The introduction of nano-SiO₂can significantly improve the performance of β-cyclodextrin-functionalized polyacrylamide in various aspects.