Encapsulation of (-)-epigallocatechin gallate into liposomes and into alginate or chitosan microparticles reinforced with liposomes

Preparation and characterization of bionics Oleosomes with high loading efficiency: The enhancement of hydrophobic space and the effect of cholesterol

Liposomes (LIP) loaded with natural active ingredients have significant potential in the food industry. However, their low loading efficiency (LE) hampers the advancement of liposomal products. To improve the loading capacity of functional compounds, bionic oleosomes (BOLE) with a monolayer of phospholipid membranes and a glyceryl tricaprylate/caprate (GTCC) oil core have first been engineered by high-pressure homogenization. TEM revealed that the core of BOLE consists of GTCC instead of water, thereby extending the hydrophobic space. Steady-state fluorescence and active loading experiments confirmed that cholesterol (CH) detached from the phospholipid membrane and entered the oil core, where it repelled cannabidiol (CBD). Based on the extending hydrophobic space, CBD-BOLE was prepared and its LE was 3.13 times higher than CBD-LIP. The CBD-phospholipid ratio (CPR) of CBD-BOLE significantly improved at least 7.8 times. Meanwhile, the free radical scavenging activity of CBD was increased and cytotoxicity was reduced.

Potential application of nanoliposomes loaded with complex tannins from the seed shell of Euryale ferox in the anti-browning of fresh-cut asparagus lettuce

Surface browning of plant-derived fresh-cut products is mainly caused by conversion of the phenolic compounds into o-quinones under tyrosinase catalysis. In this study, the rarely reported complex tannins from Euryale ferox seed shell (ECTs) constituted by the units of 35.60% condensed tannins and 64.40% hydrolysable tannins were shown to suppress the activity of tyrosinase efficiently, supporting the exploitation of ECTs into novel anti-browning agents. However, the utilization of ECTs in food preservation is often restricted because of their chemical instability to external environment. Further fabrication of nanoliposomes loaded with ECTs (ECTs-NLs) herein was carried out to improve the stability of ECTs. DLS, TEM, FTIR, DSC and XRD confirmed that ECTs were encapsulated into nanoliposomes successfully, and ECTs-NLs appeared as vesicle-like spherical morphology with favorable encapsulation efficiency, uniform particle size distribution and negative zeta-potential. The resulting ECTs-NLs were relatively stable in the dark at 4 °C. Nanoliposomal encapsulation significantly enhanced ECTs stability, thus protecting inhibitory effect of ECTs against tyrosinase. Furthermore, anti-browning evaluation proved that ECTs-NLs had distinct advantages over free ECTs in alleviating surface browning of fresh-cut asparagus lettuces. These results suggested that nanoliposomes were effective in stabilizing ECTs and ECTs-NLs could be potentially applied to the fresh-cut food industry.

Delivery of encapsulated bioactive compounds within food matrices to the digestive tract: recent trends and future perspectives

Encapsulation technologies have achieved encouraging results improving the stability, bioaccessibility and absorption of bioactive compounds post-consumption. There is a bulk of published research on the gastrointestinal behavior of encapsulated bioactive food materials alone using in vitro and in vivo digestion models, but an aspect often overlooked is the impact of the food structure, which is much more complex to unravel and still not well understood. This review focuses on discussing the recent findings in the application of encapsulated bioactive components in fabricated food matrices. Studies have suggested that the integration of encapsulated bioactive compounds has been proven to have an impact on the physicochemical characteristics of the finished product in addition to the protective effect of encapsulation on the fortified bioactive compound. These products containing bioactive compounds undergo further structural reorganization during digestion, impacting the release and emptying rates of fortified bioactive compounds. Thus, by manipulation of various food structures and matrices, the release and delivery of these bioactive compounds can be altered. This knowledge provides new opportunities for designing specialized foods for specific populations.

Preparation of VC nanoliposomes by high pressure homogenization: Process optimization and evaluation of efficacy, transdermal absorption, and stability

Vitamin C (VC) possesses antioxidant and whitening effects. However, its effectiveness is hindered by challenges such as instability, impaired solubility, and limited bioavailability hinder. In this study, VC was encapsulated in nanoliposomes by primary emulsification and high-pressure homogenization. The VC nanoliposomes were comprehensively characterized for their microscopic morphology, particle size, polydispersity index (PDI), and encapsulation efficiency (EE). Orthogonal experiments were designed to optimize the optimal preparation process, and the antioxidant activity, whitening efficacy, transdermal absorption, and stability of VC nanoliposomes were evaluated based on this optimized process. The findings demonstrated the high reproducibility of the optimal process, with particle size, PDI, and EE values of 113.502 ± 4.360 nm, 0.104 ± 0.010, and 56.09 ± 1.01 %, respectively. Differential scanning calorimetry analysis showed effective encapsulation of VC nanoliposomes with better thermal stability than aqueous VC solution. Besides, the VC nanoliposomes demonstrated excellent antioxidant and whitening effects in efficacy experiments, stronger skin permeability in transdermal experiments and fluorescence tracking. Furthermore, storage stability tests indicated that the VC in nanoliposomes remained relatively stable after 60 days of storage. These findings highlighted the potential use of VC nanoliposomes in a wide range of applications for the cosmetic market, especially in the development of ingredients for skin care products.

Biosynthesis of Nanoparticles with Green Tea for Inhibition of β-Amyloid Fibrillation Coupled with Ligands Analysis

Background

Inhibition of amyloid β protein fragment (Aβ) aggregation is considered to be one of the most effective strategies for the treatment of Alzheimer's disease. (-)-Epigallocatechin-3-gallate (EGCG) has been found to be effective in this regard; however, owing to its low bioavailability, nanodelivery is recommended for practical applications. Compared to chemical reduction methods, biosynthesis avoids possible biotoxicity and cumbersome preparation processes.

Materials and Methods

The interaction between EGCG and Aβ42 was simulated by molecular docking, and green tea-conjugated gold nanoparticles (GT-Au NPs) and EGCG-Au NPs were synthesized using EGCG-enriched green tea and EGCG solutions, respectively. Surface active molecules of the particles were identified and analyzed using various liquid chromatography-tandem triple quadrupole mass spectrometry methods. ThT fluorescence assay, circular dichroism, and TEM were used to investigate the effect of synthesized particles on the inhibition of Aβ42 aggregation.

Results

EGCG as well as apigenin, quercetin, baicalin, and glutathione were identified as capping ligands stabilized on the surface of GT-Au NPs. They more or less inhibited Aβ42 aggregation or promoted fibril disaggregation, with EGCG being the most effective, which bound to Aβ42 through hydrogen bonding, hydrophobic interactions, etc. resulting in 39.86% and 88.50% inhibition of aggregation and disaggregation effects, respectively. EGCG-Au NPs were not as effective as free EGCG, whereas multiple thiols and polyphenols in green tea accelerated and optimized heavy metal detoxification. The synthesized GT-Au NPs conferred the efficacy of diverse ligands to the particles, with inhibition of aggregation and disaggregation effects of 54.69% and 88.75%, respectively, while increasing the yield, enhancing water solubility, and decreasing cost.

Conclusion

Biosynthesis of nanoparticles using green tea is a promising simple and economical drug-carrying approach to confer multiple pharmacophore molecules to Au NPs. This could be used to design new drug candidates to treat Alzheimer's disease.

Lipid Nanoparticles: An Effective Tool to Improve the Bioavailability of Nutraceuticals

Nano-range bioactive colloidal carrier systems are envisaged to overcome the challenges associated with treatments of numerous diseases. Lipid nanoparticles (LNPs), one of the extensively investigated drug delivery systems, not only improve pharmacokinetic parameters, transportation, and chemical stability of encapsulated compounds but also provide efficient targeting and reduce the risk of toxicity. Over the last decades, nature-derived polyphenols, vitamins, antioxidants, dietary supplements, and herbs have received more attention due to their remarkable biological and pharmacological health and medical benefits. However, their poor aqueous solubility, compromised stability, insufficient absorption, and accelerated elimination impede research in the nutraceutical sector. Owing to the possibilities offered by various LNPs, their ability to accommodate both hydrophilic and hydrophobic molecules and the availability of various preparation methods suitable for sensitive molecules, loading natural fragile molecules into LNPs offers a promising solution. The primary objective of this work is to explore the synergy between nature and nanotechnology, encompassing a wide range of research aimed at encapsulating natural therapeutic molecules within LNPs.

Chitooligosaccharide-catechin conjugate loaded liposome using different stabilising agents: characteristics, stability, and bioactivities

AIM

To determine the optimum condition for preparing chitooligosaccharide-catechin conjugate (COS-CAT) liposomes using different stabilising agents.

METHODS

COS-CAT liposomes (0.1-1%, w/v) were prepared using soy phosphatidylcholine (SPC) (50-200 mM) and glycerol or cholesterol (25-100 mg). Encapsulation efficiency (EE), loading capacity (LC), physicochemical characteristics, FTIR spectra, thermal stability, and structure of COS-CAT liposomes were assessed.

RESULTS

COS-CAT loaded liposome stabilised by cholesterol (COS-CAT-CHO) showed higher stability as shown by the highest EE (76.81%) and LC (4.57%) and the lowest zeta potential (ZP) (-76.51 mV), polydispersity index (PDI) (0.2674) and releasing efficiency (RE) (53.54%) (p < 0.05). COS-CAT-CHO showed the highest retention and relative remaining bioactivities of COS-CAT under various conditions (p < 0.05). FTIR spectra revealed the interaction between the choline group of SPC and -OH groups of COS-CAT. Phase transition temperature of COS-CAT-CHO was shifted to 184 °C, which was higher than others (p < 0.05).

CONCLUSION

SPC and cholesterol-based liposome could be used as a promising vesicle for maintaining bioactivities of COS-CAT.

Nanoprecipitates of γ-cyclodextrin/epigallocatechin-3-gallate inclusion complexes as efficient antioxidants for preservation of shrimp surimi products: synthesis, performance and mechanism

BACKGROUND

Epigallocatechin-3-gallate (EGCG) is well known for excellent chain-breaking antioxidant capability. However, browning by oxidation and aggregation of EGCG is a non-negligible defect that hinders its applications as an antioxidant in various foodstuffs. Therefore, how to eliminate or mitigate browning efficiently, while retaining functionalities as food additive is a challenge in the food industry.

RESULTS

Our results demonstrated that EGCG could be anchored within the internal cavity of γ-cyclodextrin (γ-CD) to form an inclusion structure, where hydrophobic interaction, hydrogen bonding, and π-stacking were identified to be the primary drivers. The interplay between two molecules and the steric hindrance from γ-CD could restrict the motion and aggregation of EGCG efficiently, thus alleviating the browning effect. In addition, the conformational adaption of EGCG within the inclusions would result in general decreases in hydrogen-bond dissociation enthalpies for the pyrogallol-type structure on the b ring, thus enhancing the antioxidant capability. In practical application, the nanoscale γ-CD/EGCG inclusion complexes were validated preliminarily as efficient additives in the preservation of shrimp surimi, presenting significant effects on prolonging the shelf-life of products.

CONCLUSION

Here, nanoscale γ-CD/EGCG inclusion complexes as alternatives to EGCG were tailored as food antioxidants for the preservation of shrimp surimi products, exerting antioxidant effects while mitigating the browning effects of EGCG on products. Through self-assembly, EGCG would be anchored with the cavity of γ-CD, which could regulate the release modes and restrict the aggregation of EGCG. This facile strategy has great potential in food preservation. © 2023 Society of Chemical Industry.

A comprehensive review of nano-delivery system for tea polyphenols: Construction, applications, and challenges

Tea polyphenols (TPs) are important bioactive compounds in tea and have excellent physiological regulation functions. However, the extraction and purification of TPs are key technologies affecting their further application, and the chemical instability, poor bioavailability of TPs are major challenges for researchers. In the past decade, therefore, research and development of advanced carrier systems for the delivery of TPs has been greatly promoted to improve their poor stability and poor bioavailability. In this review, the properties and function of TPs are introduced, and the recent advances in the extraction and purification technologies are systematically summarized. Particularly, the intelligent delivery of TPs via novel nano-carriers is critically reviewed, and the application of TPs nano-delivery system in medical field and food industry is also described. Finally, the main limitations, current challenges and future perspectives are highlighted in order to provide research ideas for exploiting nano-delivery carriers and their application in TPs.

Quality by Design steered Development of Niclosamide Loaded Liposomal Thermogel for Melanoma: In vitro and Ex vivo Evaluation

Melanoma is the most malignant form of skin cancer across the globe. Conventional therapies are currently ineffective which could be attributed to the rampant chemo-resistance, metastasis, inability to cross the skin barriers and accumulate within the tumor microenvironment. This advent brings in the principles of drug repurposing by repositioning Niclosamide (NIC), an anthelmintic drug for skin cancer. Incorporation into the liposomes facilitated enhanced melanoma cell uptake and apoptosis. Cytotoxicity studies revealed 1.756-fold enhancement in SK-MEL-28 cytotoxicity by NIC-loaded liposomes compared to free drug. Qualitative and quantitative cell internalization indicated greater drug uptake within the melanoma cells illustrating the efficacy of liposomes as efficient carrier systems. Nuclear staining showed blebbing and membrane shrinkage. Elevated ROS levels and apoptosis shown by DCFDA and acridine orange-ethidium bromide staining revealed greater melanoma cell death by liposomes compared to free drug. Incorporating NIC liposomes into the thermogel system restricted the liposomes as a depot onto the upper skin layers. Sustained zero order release up to 48 h with liposomes and 23.58-fold increase in viscosity led to the sol-to-gel transition at 33℃ was observed with liposomal thermogel. Ex vivo gel permeation studies revealed that C-6 loaded liposomes incorporated within the thermogel successfully formed a depot over the upper skin layer for 6 h to prevent transdermal delivery and systemic adverse effects. Thus, it could be concluded that NIC loaded liposomal thermogel system could be an efficacious therapeutic alternative for the management of melanoma.

Modification of taxifolin particles with an enteric coating material promotes repair of acute liver injury in mice through modulation of inflammation and autophagy signaling pathway

PURPOSE

Taxifolin (TAX) is a flavanol compound with hepatoprotective effect, but its application is severely limited by its poor water solubility and low oral bioavailability. Therefore, it is important to urgently find a method to improve the oral bioavailability of TAX.

METHODS

In this study, hydroxypropyl methylcellulose acetate succinate modified taxifolin liposomes (HPMCAS-TAX-Lips) were prepared by a thin-film dispersion method, and a series of physicochemical properties of the liposomes were studied. The cumulative in vitro release rates of free TAX, taxifolin liposomes (TAX-Lips), and HPMCAS-TAX-Lips in the simulated gastrointestinal fluid were measured by in vitro release experiments, and the effect of HPMCAS-TAX-Lips on the human hepatoellular carcinomas (HepG2) cells was detected by MTT assay. Finally, the hepatoprotective mechanism of HPMCAS-TAX-Lips was explored through in vivo experiments.

RESULTS

The results showed that the particle size of HPMCAS-TAX-Lips was 100.44 ± 2.85 nm, the zeta potential was - 51.13 ± 0.57 mV, the PDI was 0.170 ± 0.088, and the EE was 87.9 ± 3.73%. The in vitro release results showed that the cumulative release rates of TAX-Lips and HPMCAS-TAX-Lips in simulated gastric fluid for 24 h were 92.60 ± 5.31% and 66.91 ± 1.20%, respectively. The cumulative release rates in simulated intestinal fluid for 24 h were 72.61 ± 4.38% and 53.94 ± 3.2%, respectively. The results of cytotoxicity experiments proved that HPMCAS-TAX-Lips had a significant inhibitory effect on HepG2 cells. In vivo experiments further showed that HPMCAS-TAX-Lips significantly improved the survival rate of lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver injury mice and exerted hepatoprotective effects by regulating the expression of autophagy proteins and inhibiting the activation of toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway.

CONCLUSION

This study proved the significant hepatoprotective effect of HMPCAS-TAX-Lips and provided a new idea for the application of TAX.

Alginate-based nanocarriers for the delivery and controlled-release of bioactive compounds

Alginate-based nanocarriers are propitious vehicles used for the delivery of bioactive compounds (bioactives). In this area, calcium alginate and sodium alginate are the most promising wall materials because they are nontoxic, comparatively cheap, simple in production, biocompatible and biodegradable. In this review, we have highlighted different alginate-based nanocarriers such as nanoparticles, nanofibers, nanoemulsions, nanocomplexes, and nanohydrogels; also entrapment of different bioactives within alginate nanocarriers and their bioavailability in the gastric environment has been comprehensively discussed. Being biopolymers, alginates can be exploited as emulsifiers/ encapsulants for entrapment and delivery of different bioactives such as vitamins, minerals, essential fatty acids, peptides, essential oils, bioactive oils, polyphenols and carotenoids. Furthermore, the use of alginate-based nanocarriers in combination with other polysaccharides/ emulsifiers was recognized as the most effective and favorable approach for the protection, delivery and sustained release of bioactives.

Encapsulation of EGCG by Zein-Gum Arabic Complex Nanoparticles and In Vitro Simulated Digestion of Complex Nanoparticles

Epigallocatechin gallate (EGCG) has many excellent qualities such as its antitumor, antiradiation and anti-oxidation properties, but its application is limited because its oral bioavailability is low and stability is poor. In this paper, zein and gum arabic (GA) were used as wall materials to prepare Zein-GA complex nanoparticles for encapsulating and protecting the EGCG. The particle size of Zein-GA-EGCG complex nanoparticles ranged from 128.03–221.23 nm, and the EGCG encapsulation efficiency reached a maximum of 75.23% when the mass ratio of zein to GA was 1:1. The FTIR and XRD results illustrated that the components of the Zein-GA-EGCG complex nanoparticles interacted by electrostatic, hydrogen bonding, and hydrophobic interactions. The EGCG release rate of Zein-GA-EGCG nanoparticles (16.42%) was lower than that of Zein-EGCG (25.52%) during gastric digestion, and a large amount of EGCG was released during intestinal digestion, suggesting that the Zein-GA-EGCG nanoparticles could achieve the sustained release of EGCG during in vitro digestion. Hence, using Zein-GA complexes to encapsulate EGCG effectively increased the encapsulation efficiency of EGCG and realized the purpose of sustained release during simulated gastrointestinal digestion.

Effect of Ca2+ cross-linking on the properties and structure of lutein-loaded sodium alginate hydrogels

In order to construct nano-lutein hydrogels with sustained release properties, the basic properties and structure of nano-lutein hydrogels cross-linked with different concentrations of Ca²⁺ were investigated. The results showed that the highest loading capacity for lutein reached 770.88 μg/g, while the encapsulation efficiency was as high as 99.39%. When Ca²⁺ concentration was lower than 7.5 mM, the filling of lutein nanoparticles reduced the hardness and gumminess of the hydrogel. The resilience and cohesiveness of the hydrogel decreased as the concentration of Ca²⁺ increased. Filling with lutein nanoparticles and increasing Ca²⁺ concentration both increased the G' and G″. The hydrogel loaded with lutein showed different swelling properties in different pH environments, the filling of lutein nanoparticles inhibited the swelling of the hydrogel. When Ca²⁺ concentration was greater than 7.5 mM, the cut-off amount of lutein on the surface of the Ca²⁺ cross-linked hydrogel was larger. The digestive enzymes quickly degraded the hydrogel structure, resulting in a high initial release of lutein. DSC and FTIR results showed that lutein nanoparticles were mainly physically trapped in the hydrogel network structure. Lutein nanoparticles and excessive Ca²⁺ affected the stability of cross-linked ionic bonds in the hydrogel, thereby reducing its thermodynamic stability.

Alginate-based delivery systems for food bioactive ingredients: An overview of recent advances and future trends

Due to its advantagessuch as ionic crosslinking, pH responsiveness, excellent biocompatibility, biodegradability and low price, alginate has become one of the most important natural polysaccharides extensively used in constructing desired delivery systems for food bioactive ingredients. In this review, the fundamental knowledge of alginate as a building block for construction of nutraceutical delivery systems is introduced. Then, various types of alginate-based nutraceutical delivery systems are classified and summarized. Furthermore, the future trends of alginate-based delivery systems are highlighted. Currently, alginate-based delivery systems include hydrogel, emulsion, emulsion-filled alginate hydrogel, nanoparticle, microparticle, core-shell particle, liposome, edible film, and aerogel. Although alginate has been widely used in the fabrication of food bioactive ingredient delivery systems, further efforts and improvements are still needed. For this purpose, the future perspectives of alginate-based delivery systems are discussed. The feasible research trends of alginate-based delivery systems include the development of novel large-scale commercial preparation technology, multifunctional delivery system based on alginate, alginate oligosaccharide-based delivery system and alginate-based oleogel. Overall, the objective of this review is to provide useful guidance for rational design and application of alginate-based nutraceutical delivery systems in the future.

Basic Methods for Preparation of Liposomes and Studying Their Interactions with Different Compounds, with the Emphasis on Polyphenols

Studying the interactions between lipid membranes and various bioactive molecules (e.g., polyphenols) is important for determining the effects they can have on the functionality of lipid bilayers. This knowledge allows us to use the chosen compounds as potential inhibitors of bacterial and cancer cells, for elimination of viruses, or simply for keeping our healthy cells in good condition. As studying those effect can be exceedingly difficult on living cells, model lipid membranes, such as liposomes, can be used instead. Liposomal bilayer systems represent the most basic platform for studying those interactions, as they are simple, quite easy to prepare and relatively stable. They are especially useful for investigating the effects of bioactive compounds on the structure and kinetics of simple lipid membranes. In this review, we have described the most basic methods available for preparation of liposomes, as well as the essential techniques for studying the effects of bioactive compounds on those liposomes. Additionally, we have provided details for an easy laboratory implementation of some of the described methods, which should prove useful especially to those relatively new on this research field.

Biopolymer-liposome hybrid systems for controlled delivery of bioactive compounds: Recent advances

Conventional liposomes still face many challenges associated with the poor physical and chemical stability, considerable loss of encapsulated cargo, lack of stimulus responsiveness, and rapid elimination from blood circulation. Integration of versatile functional biopolymers has emerged as an attractive strategy to overcome the limitation of usage of liposomes. This review comprehensively summarizes the most recent studies (2015-2020) and their challenges aiming at the exploration of biopolymer-liposome hybrid systems, including surface-modified liposomes, biopolymer-incorporated liposomes, guest-in-cyclodextrin-in-liposome, liposome-in-hydrogel, liposome-in-film, and liposome-in-nanofiber. The physicochemical principles and key technical information underlying the combined strategies for the fabrication of polymeric liposomes, the advantages and limitations of each of the systems, and the stabilization mechanisms are discussed through various case studies. Special emphasis is directed toward the synergistic efficiencies of biopolymers and phospholipid bilayers on encapsulation, protection, and controlled delivery of bioactives (e.g., vitamins, carotenoids, phenolics, peptides, and other health-related compounds) for the biomedical, pharmaceutical, cosmetic, and functional food applications. The major challenges, opportunities, and possible further developments for future studies are also highlighted.

Liposomal Encapsulation of Oleuropein and an Olive Leaf Extract: Molecular Interactions, Antioxidant Effects and Applications in Model Food Systems

The influence of actively/passively encapsulated oleuropein on DPPC liposomes thermal and structural properties, and its antioxidant capacity against lipid peroxidation were investigated. Also, an oleuropein-rich olive leaf extract was encapsulated in soy phosphatidylcholine (PL-90 g) and incorporated in model and commercial drinks. Oleuropein induced a concentration-dependent broadening and splitting of the gel-to-liquid phase transition temperature. Fluorescence measurements revealed a fluidizing effect on liposomes below their gel-to-liquid phase transition temperature, and a higher lipid ordering above, especially to active encapsulation. Oleuropein also showed an antioxidant effect against lipid peroxidation in PL-90 g liposomes. PL-90 g Liposomes with olive leaf extract showed a mean diameter of 405 ± 4 nm and oleuropein encapsulation efficiency of 34% and delayed oleuropein degradation at pH 2.0 and 2.8 model drinks. In conclusion, greater effects were observed on the structure and fluidity of DPPC liposomes when oleuropein was actively encapsulated, while its incorporation into acidic foods in encapsulated form could enhance its stability.

Preclinical Pharmacological Activities of Epigallocatechin-3-gallate in Signaling Pathways: An Update on Cancer

Epigallocatechin gallate (EGCG) is the main bioactive component of catechins predominantly present in svarious types of teas. EGCG is well known for a wide spectrum of biological activity as an anti-oxidative, anti-inflammatory, and anti-tumor agent. The effect of EGCG on cell death mechanisms via the induction of apoptosis, necrosis, and autophagy has been documented. Moreover, its anti-proliferative and chemopreventive action has been demonstrated in many cancer cell lines. It was also involved in the modulation of cyclooxygenase-2, in oxidative stress and inflammation of different cell processes. EGCG has been reported as a promising target for plasma membrane proteins, such as epidermal growth factor receptor (EGFR). In addition, it has been demonstrated a mechanism of action relying on the inhibition of ERK1/2, p38 MAPK, NF-κB, and vascular endothelial growth factor (VEGF). EGCG and its derivatives were used in proteasome inhibition and they were involved in epigenetic mechanisms. In summary, EGCG is the most predominant and bioactive constituent of teas and it has a pivotal role in cancer prevention. Its preclinical pharmacological activities are associated with complex molecular mechanisms that involve numerous signaling pathways.

Thermal protection and pH-gated release of folic acid in microparticles and nanoparticles for food fortification

Dispersed folic acid was successfully encapsulated in alginate–pectin hydrogels, proliposomes, and combinations thereof, providing an efficient pH-responsive delivery system.

Evaluation of EGCG Loading Capacity in DMPC Membranes

Catechins are molecules with potential use in different pathologies such as diabetes and cancer, but their pharmaceutical applications are often hindered by their instability in the bloodstream. This issue can be circumvented using liposomes as their nanocarriers for in vivo delivery. In this work, we studied the molecular details of (-)-epigallocatechin-3-gallate (EGCG) interacting with 1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC) monolayer/bilayer systems to understand the catechin loading ability and liposome stability, using experimental and computational techniques. The molecular dynamics simulations show the EGCG molecules deep inside the lipid bilayer, positioned below the lipid ester groups, generating a concentration-dependent lipid condensation. This effect was also inferred from the surface pressure isotherms of DMPC monolayers. In the polarization-modulated infrared reflection absorption spectra assays, the predominant effect at higher concentrations of EGCG (e.g., 20 mol %) was an increase in lipid tail disorder. The steady-state fluorescence data confirmed this disordered state, indicating that the catechin-induced liposome aggregation outweighs the condensation effects. Therefore, by adding more than 10 mol % EGCG to the liposomes, a destabilization of the vesicles occurs with the ensuing release of entrapped catechins. The loading capacity for DMPC seems to be limited by its disordered lipid arrangements, typical of a fluid phase. To further increase the clinical usefulness of liposomes, lipid bilayers with more stable and organized assemblies should be employed to avoid aggregation at large concentrations of catechin.

Structural characterization and biological fate of lactoferrin-loaded liposomes during simulated infant digestion

BACKGROUND

Limited information is concerned on the structure changes of liposomal delivery system under infant conditions. Positively charged lactoferrin (LF)-loaded liposomes, with the entrapment efficiency (EE) of 52.3 ± 6.3%, were prepared from soybean-derived phospholipids using a thin-layer dispersion method. The structure changes and digestibility of LF-loaded liposomes under infant conditions, including simulated gastric fluid (SGF) and simulated small intestinal fluid (SIF), were characterized in terms of the average particle size, zeta potential, turbidity, fourier transform infrared, transmission electron microscopy, lipolysis and protein hydrolysis.

RESULTS

This study showed that the functional groups, favorable membrane structure and the EE of liposomes were slightly changed as a function of time when the liposome digested under SGF conditions. However, the intact bilayer structures were damaged and the EE of LF-loaded liposomes decreased to 28.5% after digestion in infant SIF.

CONCLUSION

These results suggested that liposomal membrane could prevent the gastric degradation and the structure of liposomes was not completely destroyed with a low concentration of pancreatin and bile salts under infant conditions. Present study provided information on the insight into the characteristics of liposomes during infant gastrointestinal digestion, which was useful for the development of microcapsule systems in infant diet. © 2018 Society of Chemical Industry.

Effect of catechin liposomes on the nitrosamines and quality of traditional Chinese bacon

Liposomes are capable of increasing the nitrosamine inhibition of catechins in traditional Chinese bacon after long-term storage.

Antioxidant and Antimicrobial Effects of Catechin Liposomes on Chinese Dried Pork

In this study, catechin (CT), catechin liposome (CTL), and α-tocopherol (TP) were added to Chinese dried pork to achieve a healthy lipid composition. Their effectiveness in prevention of lipid oxidation was determined by measuring the values of thiobarbituric acid-reactive substances and peroxides. The total viable count in samples was used to identify the antimicrobial activities of CT, CTL, and TP, and the pH values of the samples were determined. Chinese dried pork with antioxidants added at 600 mg/kg was subjected to sensory evaluation. Thiobarbituric acid-reactive substance values, peroxide values, and total viable counts indicated that CTL significantly enhanced the antioxidant and antibacterial effects of CT on Chinese dried pork, especially after storage at room temperature for 25 days. Compared with the two other antioxidants, CTL could better maintain the pH stability of Chinese dried pork at room temperature. Sensory evaluation revealed that the scores of CTL were better than those of CT and TP in terms of preserving the color, flavor, tenderness, and overall acceptability of Chinese dried pork. Use of CTL in Chinese dried pork had good antioxidant and antibacterial effects and maintained color, flavor, and tenderness at a relatively stable level, suggesting that CTL could be used as an antioxidant in Chinese dried pork to enhance oxidative stability and prolong shelf life.

Antioxidant and Antimicrobial Activities of (-)-Epigallocatechin-3-gallate (EGCG) and its Potential to Preserve the Quality and Safety of Foods

Quality deterioration of fresh or processed foods is a major challenge for the food industry not only due to economic losses but also due to the risks associated with spoiled foods resulting, for example, from toxic compounds. On the other hand, there are increasing limitations on the application of synthetic preservatives such as antioxidants in foods because of their potential links to human health risks. With the new concept of functional ingredients and the development of the functional foods market, and the desire for a "clean" label, recent research has focused on finding safe additives with multifunctional effects to ensure food safety and quality. (-)-Epigallocatechin-3-gallate (EGCG), a biologically active compound in green tea, has received considerable attention in recent years and is considered a potential alternative to synthetic food additives. EGCG has been shown to prevent the growth of different Gram-positive and Gram-negative bacteria responsible for food spoilage while showing antioxidant activity in food systems. This review focuses on recent findings related to EGCG separation techniques, modification of its structure, mechanisms of antioxidant and antimicrobial activities, and applications in preserving the quality and safety of foods.

Food-grade Encapsulation Systems for (-)-Epigallocatechin Gallate

(-)-Epigallocatechin gallate (EGCG) has attracted significant research interest due to its health-promoting effects such as antioxidation, anti-inflammation and anti-cancer activities. However, its instability and poor bioavailability have largely limited its efficacy and application. Food-grade materials such as proteins, carbohydrates and lipids show biodegradability, biocompatibility and biofunctionality properties. Food-grade encapsulation systems are usually used to improve the bioavailability of EGCG. In the present paper, we provide an overview of materials and techniques used in encapsulating EGCG, in which the adsorption mechanisms of food-grade systems during in vitro digestion are reviewed. Moreover, the potential challenges and future work using food-grade encapsulates for delivering EGCG are also discussed.

Hyaluronic Acid/PLGA Core/Shell Fiber Matrices Loaded with EGCG Beneficial to Diabetic Wound Healing

During the last few decades, considerable research on diabetic wound healing strategies has been performed, but complete diabetic wound healing remains an unsolved problem, which constitutes an enormous biomedical burden. Herein, hyaluronic acid (HA)/poly(lactic-co-glycolic acid, PLGA) core/shell fiber matrices loaded with epigallocatechin-3-O-gallate (EGCG) (HA/PLGA-E) are fabricated by coaxial electrospinning. HA/PLGA-E core/shell fiber matrices are composed of randomly-oriented sub-micrometer fibers and have a 3D porous network structure. EGCG is uniformly dispersed in the shell and sustainedly released from the matrices in a stepwise manner by controlled diffusion and PLGA degradation over four weeks. EGCG does not adversely affect the thermomechanical properties of HA/PLGA-E matrices. The number of human dermal fibroblasts attached on HA/PLGA-E matrices is appreciably higher than that on HA/PLGA counterparts, while their proliferation is steadily retained on HA/PLGA-E matrices. The wound healing activity of HA/PLGA-E matrices is evaluated in streptozotocin-induced diabetic rats. After two weeks of surgical treatment, the wound areas are significantly reduced by the coverage with HA/PLGA-E matrices resulting from enhanced re-epithelialization/neovascularization and increased collagen deposition, compared with no treatment or HA/PLGA. In conclusion, the HA/PLGA-E matrices can be potentially exploited to craft strategies for the acceleration of diabetic wound healing and skin regeneration.