Development of nanoscale bioactive delivery systems using sonication: Glycyrrhizic acid-loaded cyclodextrin metal-organic frameworks

Advances in the preparation and application of cyclodextrin derivatives in food and the related fields

Cyclodextrin (CD) derivatives have recently gained worldwide attention, which have versatile advantages and restrained the defects of parent CDs. The superior properties of CD derivatives in encapsulation, stabilization, and solubilization facilitate their application in food, biomedicine, daily chemicals, and textiles. In this review, the preparation, classification, and main benefits of CD derivatives are systematically introduced. By introducing targeted groups into the parent CD molecule, they exhibit significant improvement in their required characteristic. Besides, the important point closely related to application, the safety assessment, has also been highlighted. Most tested CD derivatives have been verified to be relatively safe in a limited dosage. Then, the applications of CD derivatives have been described in detail from the food to its related field. In food field, CD derivatives play an important role in the stability and bioavailability of bioactive compounds, control flavor release, and improve the antimicrobial and antioxidant properties of packaging materials. These advantages can also be expanded to the related field, offering innovative solutions that enhance product quality, human health, and environmental sustainability. This review highlights the broad applications and potential of CD derivatives, underscoring their role in driving advancements across multiple industries.

Ultra-small gold nanoparticles embedded cyclodextrin metal-organic framework composite membrane to achieve antibacterial and humidity-responsive functions

Cyclodextrin metal-organic framework (CD-MOF) is an edible and porous material that can serve as a template for synthesizing small-sized metal nanoparticles. However, its highly hydrophilic nature has limited its wider application. Herein, ultra-small gold nanoparticles (U-AuNPs) were loaded into CD-MOF to produce a composite material Au@CD-MOF. The CD-MOF was utilized as a template to control the size of the AuNPs. The synthesized Au@CD-MOF was easily dispersible in aqueous medium and its released U-AuNPs exhibited effective water dispersion stability within 120 days. Additionally, compared to gold nanoparticles prepared using traditional methods (T-AuNPs), the U-AuNPs exhibited superior antibacterial properties. Furthermore, hydrophilic Au@CD-MOF was incorporated into a hydrophobic polydimethylsiloxane (PDMS) matrix (Au@CD-MOF/PDMS) to achieve a humidity-responsive antibacterial function. The composite membrane exhibited remarkable responsiveness to humidity, showing almost no release of U-AuNPs at 0 % humidity. However, it exhibited approximately 89 % release within 1 h, and complete release of U-AuNPs was observed within 4 h under 100 % humidity. These findings highlight the successful preparation of a humidity-responsive antibacterial composite membrane, which has great potential applications in various scenarios, particularly in the field of antibacterial food packaging.

Self-nanomicellizing solid dispersion: A promising platform for oral drug delivery

Amorphous solid dispersion (ASD) has been widely used to enhance the oral bioavailability of water-insoluble drugs for oral delivery because of its advantages of enhancing solubility and dissolution rate. However, the problems related to drug recrystallization after drug dissolution in media or body fluid have constrained its application. Recently, a self-nanomicellizing solid dispersion (SNMSD) has been developed by incorporating self-micellizing polymers as carriers to settle the problems, markedly improving the ability of supersaturation maintenance and enhancing the oral bioavailability of drug. Spontaneous formation and stability of the self-nanomicelle (SNM) have been proved to be the key to supersaturation maintenance of SNMSD system. This offers a novel research direction for maintaining supersaturation and enhancing the bioavailability of ASDs. To delve into the advantages of SNMSDs, we provide a concise review introducing the formation mechanism, characterization methods and stability of SNMs, emphasizing the advantages of SNMSDs for oral drug delivery facilitated by SNM formation, and discussing relevant research prospects.

Purification of gamma-cyclodextrin via selective coordination with potassium ions to form metal-organic frameworks

Efficient purification of gamma-cyclodextrin (γ-CD) is always challenging due to its structural similarity to other CDs and low crystallinity in water. In addressing this issue, an approach was proposed based on the formation mechanism of cyclodextrin metal-organic frameworks (CD-MOFs). This method involved the selective coordination of CDs mixture with potassium ions in water, facilitated by ethanol-induced crystallization, leading to the purification of γ-CD. The results showed that potassium ions enhanced γ-CD crystallization, and ethanol was crucial to selectively coordinating potassium ions with γ-CD. The characterizations revealed that the resulting CD-MOFs exhibited a small particle size, high surface area, and high thermal stability, and was identical to γ-CD-MOF, further indicating the final γ-CD with high purity. The separation factors of γ-CD/α-CD and γ-CD/β-CD were 309 and 260, respectively. Moreover, this method was validated through its application to the industrial enzymatic CDs mixture. The purification of γ-CD could achieve 99.99 ± 0.01 % after four crystallization cycles. Therefore, selectively coordinating with potassium ions to form MOFs provided a valuable reference for the purification of γ-CD and even the direct synthesis of γ-CD-MOF from CDs mixture. This advancement will also benefit the future production and application of γ-CD.

Cyclodextrin-based metal-organic frameworks transforming drug delivery

Cyclodextrin-based metal-organic frameworks (CD-MOFs) are gaining traction in the realm of drug delivery due to their inherent versatility and potential to amplify drug efficacy, specificity, and safety. This article explores the predominant preparation techniques for CD-MOFs, encompassing methods like vapor diffusion, microwave-assisted, and ultrasound hydrothermal approaches. Native CD-MOFs present compelling advantages in drug delivery applications. They can enhance drug loading capacity, stability, solubility, and bioavailability by engaging in diverse interactions with drugs, including host-guest, hydrogen bonding, and electrostatic interactions. Beyond their inherent properties, CD-MOFs can be customized as drug carriers through two primary strategies: co-crystallization with functional components and surface post-modifications. These tailored modifications pave the way for controlled release manners. They allow for slow and sustained drug release, as well as responsive releases triggered by various factors such as pH levels, glutathione concentrations, or specific cations. Furthermore, CD-MOFs facilitate targeted delivery strategies, like pulmonary or laryngeal delivery, enhancing drug delivery precision. Overall, the adaptability and modifiability of CD-MOFs underscore their potential as a versatile platform for drug delivery, presenting tailored solutions that cater to diverse biomedical and industrial needs.

Enhanced stability and biocompatibility of HIPEs stabilized by cyclodextrin-metal organic frameworks with inclusion of resveratrol and soy protein isolate for β-carotene delivery

High internal phase Pickering emulsions (HIPEs) constitute a significant research domain within colloid interface chemistry, addressing the demand for robust emulsion systems across various applications. An innovative nanoparticle, synthesized from a cyclodextrin metal-organic framework encapsulated with a composite of resveratrol and soy isolate protein (RCS), was employed to fortify a high internal phase emulsion. The emulsion's three-dimensional printing capabilities, alongside the encapsulated delivery efficacy for β-carotene, were thoroughly examined. Cyclodextrin metal-organic frameworks (CD-MOFs), facilitated by cellulose nanofibrils, were synthesized to yield particles at the nanoscale, maintaining a remarkable 97.67 % cellular viability at an elevated concentration of 1000 μg/ml. The RCS nanoparticles demonstrated thermal stability and antioxidant capacities surpassing those of CD-MOF. The integration of soybean isolate protein augmented both the hydrophobicity (from 21.95 ± 0.64° to 59.15 ± 0.78°) and the interfacial tension (from 14.36 ± 0.46 mN/m to 5.34 ± 0.81 mN/m) of the CD-MOF encapsulated with resveratrol, thereby enhancing the RCS nanoparticles' adsorption at the oil-water interface with greater stability. The durability of the RCS-stabilized high internal phase emulsions was contingent upon the RCS concentration. Emulsions stabilized with 5 wt%-RCS exhibited optimal physical and chemical robustness, demonstrating superior performance in emulsion 3D printing and β-carotene encapsulation delivery. This investigation furnishes a novel perspective on the amalgamation of food customization and precision nutrition.

Influence of dual succinylation and ultrasonication modification on the amino acid content, structural and functional properties of Chickpea (Cicer arietinum L.) protein concentrate

Chickpea protein, a valuable plant-based source, offers versatile applications, yet the impact of modifications like succinylation and ultrasonication on its properties remains unclear. This study explored dual succinylation and ultrasonication modification to enhance its functionality and application. Modified chickpea protein with a degree of succinylation of 96.75 %, showed enhanced water holding capacity 39.83 %, oil holding capacity 54.02 %, solubility 7.20 %, and emulsifying capacity 23.17 %, compared to native protein. Despite reduced amino acid content (64.50 %), particularly lysine, succinylation increased sulfhydryl by 1.74 %, reducing hydrophobicity (Ho) by 41.87 % and causing structural changes. Ultrasonication further reduced particle size by 82.57 % and increased zeta potential and amino acid content (57.47 %). The dual-modified protein exhibited a non-significant increase in antimicrobial activity against Staphylococcus aureus (25.93 ± 1.36 mm) compared to the native protein (25.28 ± 1.05 mm). In conclusion, succinylation combined with ultrasonication offers a promising strategy to enhance chickpea protein's physicochemical properties for diverse applications.

CD-MOFs: From preparation to drug delivery and therapeutic application

Cyclodextrin metal-organic frameworks (CD-MOFs) show considerable advantages of edibility, degradability, low toxicity, and high drug loading, which have attracted enormous interest, especially in drug delivery. This review summarizes the typical synthesis approaches of CD-MOFs, the drug loading methods, and the mechanism of encapsulation and release. The influence of the structure of CD-MOFs on their drug encapsulation and release is highlighted. Finally, the challenges CD-MOFs face are discussed regarding biosafety assessment systems, stability in aqueous solution, and metal ion effect.

Chitosan-graft-poly(lactic acid)/CD-MOFs degradable composite microspheres for sustained release of curcumin

The solubility of cyclodextrin metal-organic frameworks (CD-MOFs) in aqueous media making it not suitable as sustained-release drug carrier. Here, curcumin-loaded CD-MOFs (CD-MOFs-Cur) was embedded in chitosan-graft-poly(lactic acid) (CS-LA) via a solid-in-oil-in-oil (s/o/o) emulsifying solvent evaporation method forming the sustained-release composite microspheres. At CS-LA concentration of 20 mg/mL, the composite microspheres showed good sphericity. The average particle size of CS-LA/CD-MOFs-Cur (2:1), CS-LA/CD-MOFs-Cur (4:1) and CS-LA/CD-MOFs-Cur (6:1) composite microspheres was about 9.3, 12.3 and 13.5 μm, respectively. The above composite microspheres exhibited various degradation rates and curcumin release rates. Treating in HCl solution (pH 1.2) for 120 min, the average particle size of above microspheres reduced 28.19 %, 24.34 % and 6.19 %, and curcumin released 86.23 %, 78.37 % and 52.57 %, respectively. Treating in PBS (pH 7.4) for 12 h, the average particle size of above microspheres reduced 30.56 %, 26.56 % and 10.66 %, and curcumin released 68.54 %, 54.32 % and 31.25 %, respectively. Moreover, the composite microspheres had a favorable cytocompatibility, with cell viability of higher than 90 %. These composite microspheres open novel opportunity for sustained drug release of CD-MOFs.

γ-Cyclodextrin Metal-Organic Frameworks: Do Solvents Make a Difference?

Conventionally, methanol is the solvent of choice in the synthesis of gamma-cyclodextrin metal-organic frameworks (γ-CD-MOFs), but using ethanol as a replacement could allow for a more food-grade synthesis condition. Therefore, the aim of the study was to compare the γ-CD-MOFs synthesised with both methanol and ethanol. The γ-CD-MOFs were characterised by scanning electron microscopy (SEM), surface area and pore measurement, Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD). The encapsulation efficiency (EE) and loading capacity (LC) of the γ-CD-MOFs were also determined for curcumin, using methanol, ethanol and a mixture of the two as encapsulation solvent. It was found that γ-CD-MOFs synthesised by methanol and ethanol do not differ greatly, the most significant difference being the larger crystal size of γ-CD-MOFs crystallised from ethanol. However, the change in solvent significantly influenced the EE and LC of the crystals. The higher solubility of curcumin in ethanol reduced interactions with the γ-CD-MOFs and resulted in lowered EE and LC. This suggests that different solvents should be used to deliberately manipulate the EE and LC of target compounds for better use of γ-CD-MOFs as their encapsulating and delivery agents.

Cyclodextrin-metal-organic frameworks in molecular delivery, detection, separation, and capture: An updated critical review

Metal-organic frameworks (MOFs) are coordination compounds with tuneable structures and controllable functions. However, the biological toxicity of traditional MOFs materials is often inevitable, making their application in the biological field have many limitations. Therefore, frontier research increasingly focuses on developing biocompatible MOFs materials. Cyclodextrins (CDs), derived from starch, are favored by various biomaterials due to their good biosafety and are often seen in the preparation and application of MOFs materials. This review describes the features of MOFs materials, and the various preparation methods of CD-MOFs are analyzed in detail from the perspective of CD classification. Additionally, the promising applications of CD-MOFs materials for delivery, detection, separation, and capture of active molecules in recent studies are systematically discussed and summarized. In terms of safety, the CD-MOFs materials are meticulously summarized. Finally, this review presents the challenges and future prospects regarding the current CD-MOFs-based materials, which will shed new light on the application of such materials in various fields.

Starches in the encapsulation of plant active ingredients: state of the art and research trends

As a natural polymer, starches and their derivatives have received widespread attention in the cosmetic and pharmaceutical industries, particularly for their use as a coating material. In this sense, as an encapsulating agent, starches stand out, considering the number of compounds that they can trap. Additionally, they provide a nutritional contribution and may improve acceptance by patients. As such, this type of material may serve as an alternative to overcome gaps such as loss of activity of the active principles, low assimilation, or deterioration under environmental and physiological conditions. In this paper, we aim to present the state of the art and research trends on the use of starch as a wall material for the encapsulation of active principles of plant origin. It was found that the most-encapsulated active principles are essential oils and polyphenols; native or modified starches are typically used, either as the sole wall material or in combination with other polymers; and the most widely used methodology is spray drying. The reviewed studies indicate the potential of starches for their use in active ingredient encapsulation processes, improving their viability and expanding their range of applications in different industries, as well as showing a clearly increasing publication trend over the last 10 years.

Graphical abstract

Interactions between plant-derived antioxidants and cyclodextrins and their application for improving separation, detection, and food quality issues

Plant-derived antioxidants (PD-AOs) are important for food preservation, as well as for human health and nutrition. However, the poor chemical stability and water solubility of many PD-AOs currently limit their application as functional ingredients in foods and pharmaceuticals. Moreover, it is often difficult to isolate and detect specific antioxidants in multi-component systems, which again limits their potential in the food and medical industries. In this review, we highlight recent advances in the use of cyclodextrins (CDs) to overcome these limitations by forming simple, modified and competitive host-guest interactions with PD-AO. The host-guest properties of CDs can be used to enhance the separation efficiency of PD-AOs, as well as to improve their dispersion and stability in food systems. Moreover, the competitive complexation properties of CDs with target molecules can be used to selectively isolate PD-AOs from multi-component systems and develop detection technologies for PD-AOs. Overall, CD-antioxidant interactions have great potential for addressing isolation, detection, and food quality issues.

Comparison of the Conventional and Mechanochemical Syntheses of Cyclodextrin Derivatives

Many scientists are working hard to find green alternatives to classical synthetic methods. Today, state-of-the-art ultrasonic and grinding techniques already drive the production of organic compounds on an industrial scale. The physicochemical and chemical behavior of cyclodextrins often differs from the typical properties of classic organic compounds and carbohydrates. The usually poor solubility and complexing properties of cyclodextrins can require special techniques. By eliminating or reducing the amount of solvent needed, green alternatives can reform classical synthetic methods, making them attractive for environmentally friendly production and the circular economy. The lack of energy-intensive synthetic and purification steps could transform currently inefficient processes into feasible methods. Mechanochemical reaction mechanisms are generally different from normal solution-chemistry mechanisms. The absence of a solvent and the presence of very high local temperatures for microseconds facilitate the synthesis of cyclodextrin derivatives that are impossible or difficult to produce under classical solution-chemistry conditions. Although mechanochemistry does not provide a general solution to all problems, several good examples show that this new technology can open up efficient synthetic pathways.

Recent Advances in Metal-Organic-Framework-Based Nanocarriers for Controllable Drug Delivery and Release

Metal-organic frameworks (MOFs) have a good designability, a well-defined pore, stimulus responsiveness, a high surface area, and a controllable morphology. Up to now, various MOFs have been widely used as nanocarriers and have attracted lots of attention in the field of drug delivery and release because of their good biocompatibility and high-drug-loading capacity. Herein, we provide a comprehensive summary of MOF-based nanocarriers for drug delivery and release over the last five years. Meanwhile, some representative examples are highlighted in detail according to four categories, including the University of Oslo MOFs, Fe-MOFs, cyclodextrin MOFs, and other MOFs. Moreover, the opportunities and challenges of MOF-based smart delivery vehicles are discussed. We hope that this review will be helpful for researchers to understand the recent developments and challenges of MOF-based drug-delivery systems.

Edible pentacyclic triterpenes: A review of their sources, bioactivities, bioavailability, self-assembly behavior, and emerging applications as functional delivery vehicles

Edible pentacyclic triterpenes (PTs) are a group of nutraceutical ingredients commonly distributed in human diets. Existing evidence has proven that they have various biological functions, including anticancer, antioxidant, anti-inflammatory and hypoglycemic activities, making them as "functional factor" for a long time. However, their properties of strong hydrophobicity, poor permeability, poor absorption, and rapid metabolism result in low oral bioavailability, which dramatically hinders their efficacy for use. Recently, free PTs have successively been found to self-assemble or co-assemble into self-contained nanostructures with enhanced water dispersibility and oral bioavailability, which seems to be an efficient processing method for increased oral efficacy. Of particular interest, formulating them into nanostructures can also be introduced as functional delivery carriers for bioactive compounds or drugs with various advantages, such as improved stability, controlled release, enhanced oral bioavailability, synergistic bioactivity, and targeted delivery. This review systematically summarized the chemical structures, plant sources, bioactivities, absorption, metabolism, and oral bioavailability of PTs. Notably, we emphasized their self-assembly properties and emerging role as functional delivery carriers for nutrients, suggesting that PT nanostructures are not only efficient oral forms when introduced into foods but also functional delivery materials for nutrients to expand their commercial food applications.

Inhibitory effect of licorice extract on the germination and outgrowth of Paraclostridium bifermentans spores

INTRODUCTION

Paraclostridium bifermentans is responsible for spoilage properties in vacuum-packaged meat. Ordinary heat treatment techniques are ineffective to control the extremely heat-resistant spores of P. bifermentans. Therefore, finding a new strategy to prevent the contamination of P. bifermentans spores in vacuum-packaged meat is challenging.

METHODS

In this study, P. bifermentans was isolated from the vacuum-packaged chicken, and the inhibitory effects of licorice extract on the germination and outgrowth of P. bifermentans spores, as well as the key bioactive components in the licorice extract involved in inhibiting spore activity, were investigated.

RESULTS

The spores induced by combination-nutrient-germinant (150 mmol/L L-alanine and 20 mmol/L inosine, co-AI) did not germinate when the concentration of licorice extract was ≥ 3.13 mg/ml. The germination of P. bifermentans spores induced by non-nutrient-germinant (8 mmol/L dipicolinic acid, DPA) was completely prevented by licorice extract at least 1.56 mg/ml. While the outgrowth of P. bifermentans spores was inhibited at a concentration of 0.39 mg/ml. Licorice extract did not seem to damage the non-germinated spores but blocked the germinant sensing. Licorice extract prevented the outgrowing spores from becoming vegetable cells by disrupting the inner membrane. Furthermore, the results obtained from LC-MS data analysis exhibited 15 key bioactive compounds in licorice extract, such as glycyrrhizic acid, liquiritin, etc. Among them, glycyrrhizic acid and liquiritin apioside exerted efficient inhibitory properties on the germination and outgrowth of P. bifermentans spores.

DISCUSSION

This present study demonstrated that licorice extract can be used as a promising inhibitor of spores and provides a new method to control the residual P. bifermentans spores in meat products. Meanwhile, this study exhibits a baseline for the better understanding of the potential application of licorice extracts to control the P. bifermentans spores in meat products.

Synthesis and potential applications of cyclodextrin-based metal-organic frameworks: a review

Metal-organic frameworks are porous polymeric materials formed by linking metal ions with organic bridging ligands. Metal-organic frameworks are used as sensors, catalysts for organic transformations, biomass conversion, photovoltaics, electrochemical applications, gas storage and separation, and photocatalysis. Nonetheless, many actual metal-organic frameworks present limitations such as toxicity of preparation reagents and components, which make frameworks unusable for food and pharmaceutical applications. Here, we review the structure, synthesis and properties of cyclodextrin-based metal-organic frameworks that could be used in bioapplications. Synthetic methods include vapor diffusion, microwave-assisted, hydro/solvothermal, and ultrasound techniques. The vapor diffusion method can produce cyclodextrin-based metal-organic framework crystals with particle sizes ranging from 200 nm to 400 μm. Applications comprise food packaging, drug delivery, sensors, adsorbents, gas separation, and membranes. Cyclodextrin-based metal-organic frameworks showed loading efficacy of the bioactive compounds ranging from 3.29 to 97.80%.

Cyclodextrin metal-organic frameworks and derivatives: recent developments and applications

While there is a tremendous amount of scientific research on metal organic frameworks (MOFs) for gas storage/separation, catalysis and energy storage, the development and application of biocompatible MOFs still poses major challenges. In general, they can be synthesised from various biocompatible linkers and metal ions but particularly cyclodextrins (CDs) as cyclic oligosaccharides are an astute choice for the former. Although the field of CD-MOF materials is still in the early stages and their design and fabrication comes with many hurdles, the benefits coming from CDs built in a porous framework are exciting. Versatile host-guest complexation abilities, high encapsulation capacity and hydrophilicity are among the valuable properties inherent to CDs and offer extended and novel applications to MOFs. In this review, we provide an overview of the state-of-the-art synthesis, design, properties and applications of these materials. Initially, a rationale for the preparation of CD-based MOFs is provided, based on the chemical and structural properties of CDs and including their advantages and disadvantages. Further on, the review exhaustively surveys CD-MOF based materials by categorising them into three sub-classes, namely (i) CD-MOFs, (ii) CD-MOF hybrids, obtained via combination with external materials, and (iii) CD-MOF-derived materials prepared under pyrolytic conditions. Subsequently, CD-based MOFs in practical applications, such as drug delivery and cancer therapy, sensors, gas storage, (enantiomer) separations, electrical devices, food industry, and agriculture, are discussed. We conclude by summarizing the state of the art in the field and highlighting some promising future developments of CD-MOFs.

Preparation and characterization of an edible metal-organic framework/rice wine residue composite

In this communication, using rice wine residue (RWR) as the support, an edible γ-cyclodextrin-metal-organic framework/RWR (γ-CD-MOF/RWR) composite with a macroscopic morphology was synthesized. The obtained edible composite is promising for applications in drug delivery, adsorption, food processing, and others.

Polydimethylsiloxane Membranes Incorporating Metal-Organic Frameworks for the Sustained Release of Antibacterial Agents

Cyclodextrin metal-organic frameworks (CD-MOFs) possess great potential in environmental applications due to their high specific surface area and good biocompatibility properties. However, the hydrophilicity of the CD-MOF hinders its ability to maintain a sustained release in water as a carrier. In this study, we prepared a CD-MOF that has codelivery ability for both phytochemicals [caffeic acid (CA)] and silver nanoparticles (Ag NPs) and further incorporated this material (CA@Ag@CD-MOF) into the polydimethylsiloxane (PDMS) matrix to construct a hybrid membrane. This hybrid membrane could effectively maintain the release capacity of the CD-MOF in water, while endowing PDMS with swelling ability in water. The hybrid membrane can achieve a sustained release for up to 48 h in water. In addition, the elastic modulus of the hybrid membrane increases by nearly 100%, and the swelling degree of the hybrid membrane in water increases by 42% compared with that of the pure PDMS membrane, indicating better mechanical properties. The hybrid membrane exhibits excellent antibacterial effects on Escherichia coli O157:H7 (E. coli O157:H7) and Staphylococcus aureus (S. aureus). We expect that this work will be beneficial to the delivery research of the CD-MOF in more environmental scenarios, especially in water treatment.

Green Preparation of Robust Hydrophobic β-Cyclodextrin/Chitosan Sponges for Efficient Removal of Oil from Water

A relatively straightforward green method to fabricate robust hydrophobic sponges for effective removal of oil pollutants and other organic contaminants was developed. These sponges were constructed from bio-sources: citronellal and palmitic acid-modified aminoethyl cyclodextrin-sodium phytate-chitosan (ACCTCS). The modified sponge exhibited desirable mechanical properties and strong hydrophobicity with a water contact angle (WCA) of 147.8°. Scanning electron microscopy showed that the ACCTCS sponge had a highly porous structure that was particularly suitable for organic component absorption. The sponge exhibited excellent absorption capacities for n-hexane, trichloromethane, vacuum pump oil, and peanut oil (47.9, 32.3, 32.6, and 32.2 g/g, respectively). The removal rate of oil was more than 80% (>26.2 g/g) after 10 absorption-desorption cycles. The ACCTCS sponge also showed good oil/water and organic components/water separation performance. The bio-source materials, green preparation method, and new absorbed-oil recovery strategy provided a novel pathway to construct multifunctional absorbents for oil/water separation in industrial wastewater.

Alkali /alkaline earth-based metal-organic frameworks for biomedical applications

With the steady development of metal-organic framework (MOF) materials, this peculiar class of three-dimensional materials has found application prospects in a myriad of areas. The integration of different metals with various categories of ligands engendered a full gamut of frameworks, which of course are supplemented by diversified modification methods. Amongst many metal centers utilized to design and synthesize targeted MOFs, alkali/alkaline earth metal-based MOFs are gaining significant attention because these metal centers can be regarded as human endogenous metals. Numerous studies have shown that alkali/alkaline earth metal MOFs (A/A-E MOFs) tend to have better properties than other metals. This is because A/A-E MOFs offer better biocompatibility, so it is expected to be used in a broader field of biomedicine in the near future. This review mainly introduces the application of A/A-E MOF materials in drug delivery, sensing, and some materials with unique biomedical applications, and elaborates the challenges, obstacles and development of some A/A-E MOF materials in the biomedical field.

A nanodrug system overexpressed circRNA_0001805 alleviates nonalcoholic fatty liver disease via miR-106a-5p/miR-320a and ABCA1/CPT1 axis

Our study aimed to explore the function of circRNA_0001805 in the pathogenesis of NAFLD and the underlying mechanism. A nanodrug system (GA-RM/GZ/PL) was constructed to overexpress circRNA_0001805 specifically in hepatocytes for the treatment of NAFLD. Fat droplet accumulation in cultured cells and mouse hepatic tissues was detected using Oil Red O or H&E staining. The relative expression of circRNAs, genes associated with lipogenesis was quantified by qRT-PCR. Interactions between circRNA_0001805 and miR-106a-5p/miR-320a, between miR-106a-5p/miR-320a and ABCA1/CPT1 were confirmed by dual-luciferase reporter assay. A novel metalorganic framework nanocarrier (GZ) was prepared from glycyrrhizic acid and zinc ions (Zn²⁺), and this nanocarrier was loaded with the circRNA_0001805 plasmid to construct a nanocore (GZ/PL). Then, this GZ/PL was coated with a galactose-modified RBC membrane (GA-RM) to generate GA-RM/GZ/PL. CircRNA_0001805 expression was downregulated in FFA-challenged primary hepatocytes, HFD-fed mice and NAFLD patients. Overexpressed circRNA_0001805 attenuated NAFLD development by suppressing lipid metabolism disorder and inflammation. CircRNA_0001805 targeted miR-106a-5p/miR-320a, which served as an upstream inhibitor of ABCA1/CPT1 and collaboratively regulated NAFLD progression. GA-RM/GZ/PL targeted hepatocytes, overexpressed circRNA_0001805, released glycyrrhizic acid to reduce the accumulation of lipids in the liver and played a synergistic role against NAFLD-induced lipid metabolism disorder.

Metal-organic frameworks for food applications: A review

Metal-organic frameworks (MOFs) are high surface-to-volume ratio crystalline hybrid porous coordination materials composed of metal ions as nodes and organic linkers. The goal of this paper was to provide an updated and comprehensive state-of-the-art review of MOFs for different food applications such as active food contact materials, antimicrobial nanocarriers, controlled release nanosystems for active compounds, nanofillers for food packaging materials, food nanoreactors, food substance nanosensors, stabilizers and immobilizers for active compounds and enzymes, and extractors of food contaminants. Extraction and sensing of several food contaminants have been the main food applications of MOFs. The other applications listed above require further investigation, as they are at an early stage. However, interesting results are being reported for these other fields. Finally, an important limitation of MOFs has been the use of non-renewable feedstocks for their synthesis, but this has recently been solved through the manufacture and use of γ-cyclodextrin-based MOFs.

Novel γ-cyclodextrin-metal-organic frameworks for encapsulation of curcumin with improved loading capacity, physicochemical stability and controlled release properties

A safe and biodegradable γ-cyclodextrin-metal-organic-frameworks (γ-CD-MOFs) was successfully synthesized by using an improved hydrothermal method. In this study, curcumin (Cur) was chosen for testing the encapsulation stability and release performance of γ-CD-MOFs. Results of the crystal structure measurement indicated that the encapsulated curcumin within γ-CD-MOFs via van der Waals forces, hydrophobic interactions and hydrogen bonding was failed to disturb the inherent microtopography and crystallinity of γ-CD-MOFs. Compared to individual γ-CD, the γ-CD-MOFs exhibited improved loading capacity, physicochemical stability as well as controlled-release property in simulated digestion, and hence can be regarded as effective carriers for curcumin. Curcumin-loaded γ-CD-MOFs with a Cur : γ-CD-MOFs mass ratio of 2:3 (Cur-CD-MOFs/3), which showed the highest encapsulation efficiency (67.31 ± 2.25%), improved physicochemical stability and controlled-release performance, was selected for further research and industrialization. Our results demonstrate that γ-CD-MOFs can be regarded as a promising novel carrier for the delivery of curcumin or other hydrophobic nutraceuticals.

Recent Advances in Antiinflammatory Material Design

Implants and prostheses are widely used to replace damaged tissues or to treat various diseases. However, besides the risk of bacterial or fungal infection, an inflammatory response usually occurs. Here, recent progress in the field of anti-inflammatory biomaterials is described. Different materials and approaches are used to decrease the inflammatory response, including hydrogels, nanoparticles, implant surface coating by polymers, and a variety of systems for anti-inflammatory drug delivery. Complex multifunctional systems dealing with inflammation, microbial infection, bone regeneration, or angiogenesis are also described. New promising stimuli-responsive systems, such as pH- and temperature-responsive materials, are also being developed that would enable an "intelligent" antiinflammatory response when the inflammation occurs. Together, different approaches hold promise for creation of novel multifunctional smart materials allowing better implant integration and tissue regeneration.

Preparation of coix seed oil bioactive delivery systems based on homologous polysaccharides and proteins

Natural products belonging to a class of generally-recognized-as-safe biomaterials have exceptional biocompatibility and biodegradability and can be used as delivery vehicles for a variety of functional foods. Adlay (Coix lacryma-jobi), is a nutritious food, rich in various bioactive ingredients. Coix seed oil extract (CSO) is also bioactive but it is sensitive to oxidation. In this study, a bioactive delivery system based on homologous polysaccharides and proteins was developed to deliver coix seed oil. The results show that the CSO nanoparticles have high encapsulation efficiency, narrow particle size distribution, and good stability. Moreover, the fusion of the nanoparticles with the membrane enabled the transport of CSO through the Caco-2 cell monolayer and improved the intestinal permeability. These findings could provide useful information for designing homologous polysaccharide and protein-based delivery systems to increase the bioavailability of lipophilic nutraceuticals in the food industry.