Incorporation of phytosterols in soy phospholipids nanoliposomes: Encapsulation efficiency and stability

Liposomal and Liposomes-Film Systems as Carriers for Bioactives from Paeonia tenuifolia L. Petals: Physicochemical Characterization and Biological Potential

Paeonia tenuifolia L. (steppe peony) petal extract was proficiently encapsulated into liposomes and biopolymer films in the current work, both times utilizing a single-step procedure. The encapsulation efficiency, size of the particles, and index of polydispersity (PDI), as well as the ζ potential of the obtained liposomes were determined, whereas in the case of films, the test included moisture content and mechanical property assessment. Fourier transform infrared spectroscopy (FT-IR) was used to evaluate the chemical composition and existence of numerous interactions in the systems. All the obtained encapsulates were subjected to antibacterial, antifungal and antibiofilm activity testing of the pathogens associated with human skin. The results indicated that the liposomes prepared using Phospholipon had the highest encapsulation efficiency (72.04%), making them the most favorable ones in the release study as well. The biological assays also revealed that Phospholipon was the most beneficial phospholipid mixture for the preparation of liposomes, whereas the film containing these liposomes did not have the ability to inhibit pathogen growth, making the double encapsulation of P. tenuifolia L. petal extract needless. These findings may be a first step toward the potential use of steppe peony extract-loaded films and liposomes in pharmaceutical and cosmetical industries.

The effect of essential oil of Anethum graveolens L. seed and gallic acid (free and nano forms) on microbial, chemical and sensory characteristics in minced meat during storage at 4 °C

The aim of this study was to evaluate the effect of gallic acid (GA) and essential oil (EO) of Anethum graveolens L. seed (forms of nanoliposome and free) on bacteriological, chemical and sensory properties of minced meat during storage. In this research, Escherichia coli (gram negative) and Staphylococcus aureus (gram positive) were used to examine the effect of these compounds on meat. The particle sizes (z-average diameter) of prepared nanoliposomes of EO and GA were in the range of 141 to 165 nm and 146-160 nm, respectively and the efficiency of encapsulation (EE %) in the current research was 51.76-69.8% in nano EO (NEO) and 53.23-67.07% in nano gallic acid (N-GA). Also, the outcomes indicated the treatment containing nano-liposomes had a better antimicrobial effect in both of bacteria. In present study, the Minimum Inhibitory Concentration (MIC) of GA, N-GA, EO and NEO for S. aureus was 0.62 ± 0.01, 0.62 ± 0.02, 0.62 ± 0.01 and 0.62 ± 0.01 mg/mL, respectively, and for E. coli was 0.62 ± 0.01, 0.62 ± 0.01, 1.25 ± 0.1 and 1.25 ± 0.1 mg/mL, respectively. Also, the results showed MBC (The Minimum Bactericidal Concentration) of GA, N-GA, EO and NEO for S. aureus was 0.62 ± 0.02, 0.62 ± 0.03, 1.25 ± 0.1 and 1.25 ± 0.1 mg/mL, respectively, and for E. coli was0.62 ± 0.01, 1.25 ± 0.1, 2.5 ± 0.2, 2.5 ± 0.2 mg/mL, respectively. The highest and lowest of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were detected, in the Butylated hydroxytoluene (BHT) 200 and EO1%, respectively. Furthermore, after 18 day, minimum pH and Total volatile basic nitrogen (TVB-N) value were related to the N-GA2% on S. aureus with pH = 6.5 and NEO group (27 mg N/100 g), respectively. Finally, the treatment of NEO showed a higher acceptance score of sensory evaluation after 18 days. According to the outcomes of current investigation, the use of nanocapsulated EO and GA are effective (as a coating for food storage) and can increase the shelf life of minced meat.

Solubilization of free β-sitosterol in milk sphingomyelin and polar lipid vesicles as carriers: Structural characterization of the membranes and sphingosome morphology

High consumption of plant sterols reduces the risk of cardiovascular diseases in humans and provides health benefits. Increasing the amount of plant sterols in the diet is therefore necessary to reach the recommended daily dietary intake. However, food supplementation with free plant sterols is challenging because of their low solubility in fats and water. The objectives of this study were to investigate the capacity of milk-sphingomyelin (milk-SM) and milk polar lipids to solubilise β-sitosterol molecules in bilayer membranes organised as vesicles called sphingosomes. The thermal and structural properties of milk-SM containing bilayers composed of various amounts of β-sitosterol were examined by differential scanning calorimetry (DSC) and temperature-controlled X-ray diffraction (XRD), the molecular interactions were studied using the Langmuir film technique, the morphologies of sphingosomes and β-sitosterol crystals were observed by microscopy. We showed that the milk-SM bilayers devoid of β-sitosterol exhibited a gel to fluid L_α phase transition for T_m = 34.5 °C and formed facetted spherical sphingosomes below T_m. The solubilisation of β-sitosterol within milk-SM bilayers induced a liquid-ordered L_o phaseabove 25 %mol (1.7 %wt) β-sitosterol and a softening of the membranes leading to the formation of elongated sphingosomes. Attractive molecular interactions revealed a condensing effect of β-sitosterol on milk-SM Langmuir monolayers. Above 40 %mol (25.7 %wt) β-sitosterol, partitioning occured with the formation of β-sitosterol microcrystals in the aqueous phase. Similar results were obtained with the solubilization of β-sitosterol within milk polar lipid vesicles. For the first time, this study highlighted the efficient solubilization of free β-sitosterol within milk-SM based vesicles, which opens new market opportunities for the formulation of functional foods enriched in non-crystalline free plant sterols.

A Comprehensive Review on Nutraceuticals: Therapy Support and Formulation Challenges

Nutraceuticals are the nourishing components (hybrid of nutrition and pharmaceuticals) that are biologically active and possess capability for maintaining optimal health and benefits. These products play a significant role in human health care and its endurance, most importantly for the future therapeutic development. Nutraceuticals have received recognition due to their nutritional benefits along with therapeutic effects and safety profile. Nutraceuticals are globally growing in the field of services such as health care promotion, disease reduction, etc. Various drug nutraceutical interactions have also been elaborated with various examples in this review. Several patents on nutraceuticals in agricultural applications and in various diseases have been stated in the last section of review, which confirms the exponential growth of nutraceuticals' market value. Nutraceuticals have been used not only for nutrition but also as a support therapy for the prevention and treatment of various diseases, such as to reduce side effects of cancer chemotherapy and radiotherapy. Diverse novel nanoformulation approaches tend to overcome challenges involved in formulation development of nutraceuticals. Prior information on various interactions with drugs may help in preventing any deleterious effects of nutraceuticals products. Nanotechnology also leads to the generation of micronized dietary products and other nutraceutical supplements with improved health benefits. In this review article, the latest key findings (clinical studies) on nutraceuticals that show the therapeutic action of nutraceutical's bioactive molecules on various diseases have also been discussed.

Incorporation of white tea extract in nano-liposomes: optimization, characterization, and stability

BACKGROUND

In the present study, an extraction method affected by sonication intensity (40%, 70% and 100%), sonication time (5, 10 and 15 min) and different solvents (ethanol, methanol and a combination of ethanol/methanol) was optimized to extract the white tea with the greatest polyphenolic compounds using a response surface methodology. To prepare the nano-liposomal vesicles, phospholipids and cholesterol in various proportions (60:0, 40:20, 30:30 and 20:40) were applied based on thin-film hydration and ultrasound method. The nano-capsules enriched in bioactive compounds were examined through particle characteristics, encapsulation efficiency, morphological analysis, thermal properties and Fourier transform infrared spectroscopy.

RESULTS

The observations showed that the extraction yield highly depended on the type of solvent with varying permeability, sonication time and power. The highest total phenolic content (68.38 mg GA g^-1 ) and free radical scavenging activity (77.65%) were observed for the following optimal conditions: 70% for sonication intensity, 15 min for sonication time and methanol as solvent. Characteristics of nanoliposomes within a compositional ratio of lecithin/cholesterol (40:20) and with a zeta potential of -56 ± 0.01 mV, as well as white tea extract (WTE) samples with an average particle diameter of 82.20 ± 0.08, microencapsulation efficiency of 76.5% ± 0.081, polydispersity index of 0.06 ± 0.02 and span value of 0.69 ± 0.03. are used as the optimal formulation for microencapsulation of antioxidant WTE. The results demonstrated an increment in thermal stability of liposomal WTE samples compared to other samples.

CONCLUSION

The findings of the present study indicated that nano-liposomes comprise an effective technology for coating the WTE, as well as to increasing its stability and thermal properties. © 2021 Society of Chemical Industry.

Development of Stable Tocopherol Succinate-Loaded Ethosomes to Enhance Transdermal Permeation: In-Vitro and In-Vivo Characterizations

BACKGROUND

Tocopherol succinate (TS) represents synthetic derivative of α-tocopherol (vitamin E), it act as anti-aging, moisturizing and antioxidant. Ultraviolet (UV) photo stability of TS is low and it cause skin irritation.

AIM

To develop tocopherol succinate loaded ethosomal gel for topical TS delivery and to evaluate its moisturizing and anti-aging effects.

METHOD

Cold method technique was used to produce ethosomal formulations (N=9) by varying ethanol and lipid concentrations (F1-F9). The most optimized formulation (F5) was selected for further study on the basis of characterization. F5 Formulation was incorporated into gel. Ex vivo permeation study was done by using Franz diffusion cell. Non-invasive in-vivo study was performed by using corneometer for evaluation of skin moisture content and skin mechanical properties by using cutometer, for 12 weeks on human subjects (N=13).

RESULTS

Particle size (PS), zeta potential (ZP) and polydispersity index (PDI), Entrapment efficiency were found to be 179.1 nm, -13.7 mV and 0.345, 99.71% respectively. TEM depicted spherical ethosomal particles. Ethosomal gel and control gel were evaluated for Conductivity and pH. Rheological analysis revealed a non-Newtonian flow. The release profile showed Initial burst and then sustained release, release data followed Korsmeyer-Peppas model. TS loaded ethosomal gel appeared physically stable and showed significant results in terms of skin capacitance and mechanical properties.

CONCLUSION

The prepared ethosomal gel formulation containing TS is more stable with enhanced antioxidant, moisturizing properties and increased TS deposition into the skin layer.

Production, Characterization, Delivery, and Cholesterol-Lowering Mechanism of Phytosterols: A Review

Phytosterols are natural plant-based bioactive compounds that can lower blood cholesterol levels and help prevent cardiovascular diseases. Consequently, they are being utilized in functional foods, supplements, and pharmaceutical products designed to improve human health. This paper summarizes different approaches to isolate, purify, and characterize phytosterols. It also discusses the hypolipidemic mechanisms of phytosterols and their impact on cholesterol transportation. Phytosterols have a low water-solubility, poor chemical stability, and limited bioavailability, which limits their utilization and efficacy in functional foods. Strategies are therefore being developed to overcome these shortcomings. Colloidal delivery systems, such as emulsions, oleogels, liposomes, and nanoparticles, have been shown to be effective at improving the water-dispersibility, stability, and bioavailability of phytosterols. These delivery systems can be used to incorporate phytosterols into a broader range of cholesterol-lowering functional foods and beverages. We also discuses several issues that need to be addressed before these phytosterol delivery systems can find widespread commercial utilization.

The Effect of the Liposomal Encapsulated Saffron Extract on the Physicochemical Properties of a Functional Ricotta Cheese

In this study, the encapsulation of saffron extract (SE) was examined at four various concentrations of soy lecithin (0.5%–4% w/v) and constant concentration of SE (0.25% w/v). Particle size and zeta potential of liposomes were in the range of 155.9–208.1 nm and −34.6–43.4 mV, respectively. Encapsulation efficiency was in the range of 50.73%–67.02%, with the stability of nanoliposomes in all treatments being >90%. Encapsulated SE (2% lecithin) was added to ricotta cheese at different concentrations (0%, 0.125%, 1%, and 2% w/v), and physicochemical and textural properties of the cheese were examined. Lecithin concentration significantly (p ≤ 0.05) affected the particle size, zeta potential, stability, and encapsulation efficiency of the manufactured liposomes. In terms of chemical composition and color of the functional cheese, the highest difference was observed between the control cheese and the cheese enriched with 2% liposomal encapsulated SE. Hardness and chewiness increased significantly (p ≤ 0.05) in the cheeses containing encapsulated SE compared to the control cheese. However, there was no significant difference in the case of adhesiveness, cohesiveness, and gumminess among different cheeses. Overall, based on the findings of this research, liposomal encapsulation was an efficient method for the delivery of SE in ricotta cheese as a novel functional food.

Effects of Phytosterol Butyrate Ester on the Characteristics of Soybean Phosphatidylcholine Liposomes

The nutritional and structural properties of phytosterols (PS)/phytosterol esters (PEs) facilitate their use as substitutes for cholesterol in liposome encapsulation systems designed for oral drugs and health products. The purpose of this study was to determine the effect of phytosterol butyrate ester (PBE) on the properties of liposomes. PBE was encapsulated within liposomes (approximately 60 nm) prepared using soybean phosphatidylcholine using the thin-film hydration method. There was no significant change in the average particle diameter and zeta potential of these liposomal vesicles corresponding to the increasing amounts of encapsulated PBE. The incorporation of PBE increased the polydispersity index (PDI) independent of concentration. Additionally, we observed that the storage stability of PBE liposomes with uniform particle size and approximately spherical shape vesicle was better at low concentration. The results of Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy showed that PBE was positioned at the water interface, which increased the order of hydrophobic alkyl chains in the lipid membranes. The incorporation of PBE led to an increase in the trans conformation of hydrophobic alkyl chain and consequently, the thermal stability of liposomes, which was confirmed by differential scanning calorimetry (DSC). The results of powder X-ray diffraction (XRD) analysis confirmed that PBE was present in an amorphous form in the liposomes. Additionally, the incorporation of PBE reduced the micropolarity of the lipid membrane. Thus, when preparing liposomes using thin-film hydration, the presence of PBE affected the characteristics of liposomes.

Nanoliposomal thyme (Thymus vulgaris) essential oil: Effects of formulation parameters

Essential oils with antimicrobial or antioxidant activities have received extensive attention among customers, manufacturers, and food scientists, especially with rising worries about the safety of synthetic food preservatives. However, like other functional lipid compounds their incorporation into aqueous systems is challenging, due to their less water solubility. Furthermore, their susceptibility to light, moisture, heat, and oxygen origins their less chemical and structural stabilities. Consequently, the present research was aimed to encapsulate the thyme essential oil into nanoliposomes, using a thin layer hydration-sonication technique, which can be a proficient solution for revealed problems. The effects of phospholipid and stabilizing agents' concentrations, namely, lecithin, cholesterol, and glycerol, as main formulation parameters were investigated on characteristics of gained nanoliposomes, using a response surface method. Various empirical models were also developed to predict product characteristics by changing the formulation parameters. According to the numerical multiple optimizations, the best thyme oil nanoliposomes can be gained using equal concentrations of all three components as 1% with a mean particle size of 189.6 nm, PDI of 0.3487, the net zeta-potential of 42.48 mV, and DPPH radical scavenging of 12.72%. The prepared nanoliposomes had acceptable physical but limited chemical stabilities. The antibacterial action of manufactured essential oil nanoliposomes against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus has made them efficient candidates as natural food preservatives.

A review on chemical and physical modifications of phytosterols and their influence on bioavailability and safety

Phytosterols have been shown to lower cholesterol levels and to have antioxidant, anti-inflammatory and other biological activities. However, the high melting point and poor solubility limit their bioavailability and practical application. It is advantageous to modify phytosterols chemically and physically. This article reviews and discusses the chemical and physical modifications of phytosterols, as well as their effects on the bioavailability and possible toxicity in vivo. The current research on chemical modifications is mainly focused on esterification to increase the oil solubility and water solubility. For physical modifications (mainly microencapsulation), there are biopolymer-based, surfactant-based and lipid-based nanocarriers. Both chemical and physical modifications of phytosterols can effectively increase the absorption and bioavailability. The safety of modified phytosterols is also an important issue. Phytosterol esters are generally considered to be safe. However, phytosterol oxides, which may be produced during the synthesis of phytosterol esters, have shown toxicity in animal models. The toxicity of nanocarriers also needs further studies.

Effects of nano-chitosan coatings incorporating with free /nano-encapsulated cumin (Cuminum cyminum L.) essential oil on quality characteristics of sardine fillet

Nowadays, adding biological compounds to food packaging is one of the types of active packaging. The aim of this study was to prepare a new degradable coating with free and nano-encapsulated Cumino cyminum L. essential oil (CCEO) with nanochitosan (Nch) base to evaluate the microbial, chemical and sensory properties of sardine fillet samples for 16 days at 4 °C. Nanoliposome using different soy lecithin ratios and cholesterol concentrations (60:0, 50:10, 40:20, and 30:30) and technique of thin-film hydration-sonication, were prepared with a range of 140-164 nm size. Encapsulation efficiency (EE) and distribution of nanoliposomes size were calculated 0.80-0.90 and 49.85-73.01% respectively. To coat sardine fillet samples, nanoliposomes with the lower size of droplet and higher EE percent were selected. The outcomes indicated that coating treatments can effectively inhibit microbial growth and chemical spoilage reflected at lower pH, peroxide value (PV) and thiobarbituric acid reactive substances (TBARs) (P < 0.05). In fact, the results of chemical and microbiological characteristics showed that the samples treated with nanocitosan/nano essential oil (NEO) showed the lowest value among other treatments during the experimental period, in the following, Nch-EO, Nch and control. pH, PV, TBARs, total viable counts (TVC), total pseudomonads count (TPC), and lactic acid bacteria (LAB) were 6.85, 0.03 (mg MDA/kg), 5.23 (mEq/kg), 3.67 (CFU/g), 3.47 (CFU/g), and 4.7 (CFU/g), respectively for Nch-NEO at the end of storage time. In addition, during the experimental period, the highest sensory properties were obtained for the Nch-NEO group. Encapsulation of CCEO reduces the rate of diffusion, thus increasing antimicrobial and antioxidant activity, as well as improving sensory properties. According to the results of this study, CCEO-encapsulated nanochitosan coatings can be used as a potent coating to increase sardine shelf life.

Development of nanochitosan-based active packaging films containing free and nanoliposome caraway (Carum carvi. L) seed extract

The biocompatible active films were prepared based on nanochitosan (NCh) containing free and nanoliposome caraway seed extract (NLCE). The produced films were characterized by physico-mechanical, barrier, structural, color, antimicrobial, and antioxidant properties. The average particle size of NLCE was 78-122 nm, and the encapsulation efficiency (EE%) was obtained 49.87%-73.07%. Nanoliposomes with the lowest size and the highest encapsulation efficiency were merged with the film samples. NCh/CE3% and NCh/NLCE3% films had higher stability compared to other films and showed the highest antimicrobial activity (3.68 mm inhibition) and radical quenching capacity (51%), respectively. Likewise, biodegradable active films containing nanoliposomes had lower antimicrobial potential and higher antioxidant capacity than films containing free extract with similar concentration. The Fourier-transform infrared spectroscopy (FTIR) results revealed new interactions between NCh and nanoliposomes. Scanning electron microscopy (SEM) investigation also exhibited a homogenous structure and nearly smooth surface morphology with a good dispersion for NCh/NLCE films. Despite an increase in yellowness (b value) and a decrease in whiteness (L value) index, the incorporation of nanoliposomes within the NCh films improved the mechanical flexibility (from 10.2% to 15.05%) and reduced water vapor permeability (WVP) (from 14.2 × 10-12 g/m·s·Pa to 11.9 × 10-12 g/m·s·Pa). Today, due to the growing trend toward natural ingredients, the use of nanoparticles derived from plant derivatives has expanded in the food industry owing to their antimicrobial and antioxidant properties.

Impact of Quercetin Encapsulation with Added Phytosterols on Bilayer Membrane and Photothermal-Alteration of Novel Mixed Soy Lecithin-Based Liposome

This study used highly lipophilic agents with an aim to increase the oxidant inhibitory activity and enhance photothermal stability of a novel mixed soy lecithin (ML)-based liposome by changing the composition of formulation within the membrane. Specifically, the development and optimization of the liposome intended for improving Trolox equivalent antioxidant capacity (TEAC) value and %TEAC loss was carried out by incorporating a natural antioxidant, quercetin (QU). In this context, a focus was set on QU encapsulation in ML-based liposomes and the concentration-dependent solubility of QU was investigated and calculated as encapsulation efficiency (EE). To explore the combined effects of the incorporation of plant sterols on the integrity and entrapment capacity of mixed phospholipid vesicles, conjugation of two types of phytosterols (PSs), namely β-sitosterol (βS) and stigmasterol (ST), to mixed membranes at different ratios was also performed. The EE measurement revealed that QU could be efficiently encapsulated in the stable ML-based liposome using 0.15 and 0.1 g/100 mL of βS and ST, respectively. The aforementioned liposome complex exhibited a considerable TEAC (197.23%) and enhanced TEAC loss (30.81%) when exposed to ultraviolet (UV) light (280-320 nm) over a 6 h duration. It appeared that the presence and type of PSs affect the membrane-integration characteristics as well as photodamage transformation of the ML-based liposome. The association of QU with either βS or ST in the formulation was justified by their synergistic effects on the enhancement of the EE of liposomes. Parallel to this, it was demonstrated that synergistic PS effects could be in effect in the maintenance of membrane order of the ML-based liposome. The findings presented in this study provided useful information for the development and production of stable QU-loaded ML-based liposomes for food and nutraceutical applications and could serve as a potential mixed lipids-based delivery system in the disease management using antioxidant therapy.

Microencapsulation as a Tool for the Formulation of Functional Foods: The Phytosterols' Case Study

Hypercholesterolemia, which is an increase in total and low-density lipoprotein (LDL) serum cholesterol, is an important risk factor for the development of cardiovascular diseases. Lifestyle modifications underpin any action plan for reducing serum cholesterol. Phytosterols are natural compounds belonging to the triterpenes family. Thanks to their structural analogy with cholesterol, phytosterols have the ability to reduce serum LDL-cholesterol levels. Phytosterols are used to enrich or fortify a broad spectrum of food products. Like unsaturated fatty acids and cholesterol, phytosterols are easily oxidized. Microencapsulation could be a useful tool to overcome this and other drawbacks linked to the use of phytosterols in food fortification. In this review, in addition to explaining the phytosterols’ mechanisms of action, a focus on the use of free and encapsulated phytosterols for the formulation of functional foods, taking also into account both technological and legislative issues, is given.

Mild and Efficient Preparation of Phytosteryl Amino Acid Ester Hydrochlorides and Their Emulsifying Properties

The aim of this work was to produce a series of phytosteryl amino acid ester hydrochlorides by a two-step method, which involved esterification of phytosterols with N- tert-butoxycarbonyl (BOC) amino acid and deprotection of the BOC group. The highest yield of over 95.0% was obtained when the catalysts were the mixtures of 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochlide, 4-dimethylaminopyridine, and triethylamine. It was found that batch charging of the reactants and catalysts was conducive to improving the yield. In addition, over 99.0% of the BOC group deprotection degree was achieved using the HCl/ethyl acetate deprotection method. All of the compounds were characterized by fourier transform infrared spectroscopy, mass spectroscopy, and nuclear magnetic resonance spectroscopy. The emulsifying properties of phytosterols and phytosteryl amino acid ester hydrochlorides were also investigated. The results showed higher emulsifying properties of phytosteryl amino acid ester hydrochlorides, which could favor its wide application in food systems.

New formulation of vitamin C encapsulation by nanoliposomes: production and evaluation of particle size, stability and control release

In the present study, the effects of different ratios of milk phospholipids, cholesterol and phytosterols (Campesterol) powder (50-100%, 0-50%, and 0-50%, respectively) and sonication time (20, 25, 30, 35 and 40 min) were investigated to produce a new formulation of nanoliposomes for encapsulation of vitamin C. The results showed that increasing the time of sonication and decreasing the ratio of phospholipid to phytosterol significantly decreased nanoliposomes' particle size (p < 0.05). The maximum encapsulation efficiency was obtained at 35 and 40 min of sonication time and 75-25 ratio of phospholipid: phytosterol. Also, reducing the sonication time in the same ratio of phospholipid/phytosterol caused to increase the controlled release. The highest stability of vitamin C during 20 days was obtained in the ratio of 75-25 (phospholipids: campesterol). The results showed a positive effect of cholesterol replacement with campesterol on encapsulation efficiency, control release and stability of vitamin C in nanoliposomes.

Preparation of alginate oligosaccharide nanoliposomes and an analysis of their inhibitory effects on Caco-2 cells

The conditions were optimised for preparing Alginate oligosaccharide (AOS) nanoliposomes, and Caco-2 cell experiments were carried out to examine their antitumour effects. The optimal formulation of AOS nanoliposomes was as follows: a phosphatidylcholine-to-cholesterol ratio of 5.12, AOS concentration of 8.44 mg/mL, Tween 80 concentration of 1.11%, and organic phase to aqueous phase ratio of 5.25. Under the above conditions, the experimental encapsulation efficiency was 65.84%, and the AOS nanoliposomes exhibited a small particle size of 323 nm. After Caco-2 cells were treated with AOS liposomes and AOS for 24 h, AOS nanoliposomes inhibited the growth of Caco-2 cells to a greater extent than AOS at concentrations of 0.0625, 0.125, 0.25, 0.5 and 1 mg/mL (P < 0.01). LDH leakage exhibited a concentration-dependent increase following treatment with 0.5-1 mg/mL AOS nanoliposomes, and the inhibitory effect of AOS nanoliposomes exhibited a more significant difference than AOS (P < 0.01). Cells treated with 0.5 mg/mL and 1 mg/mL AOS nanoliposomes displayed a substantial and significant increase in activity compared with AOS (P < 0.01). Based on these results, AOS nanoliposomes exerted a more significant effect on inhibiting Caco-2 cell proliferation than AOS.

The effect of sterol derivatives on properties of soybean and egg yolk lecithin liposomes: Stability, structure and membrane characteristics

The effects of three kinds of sterols (cholesterol, β-sitosterol and ergosterol) on the stability, microstructure and membrane properties of soybean and egg yolk lecithin liposomes were investigated by light scattering, transmission electron microscope (TEM), atomic force microscope (AFM), fluorescence and Fourier transform infrared spectroscopy (FTIR). The vesicle size of cholesterol or β-sitosterol incorporated liposomes was higher than that of the control and ergosterol incorporated ones, while the zeta-potential was similar when the same lecithin was used. Due to the excellent emulsifying capacity, Tween-80 was introduced into the system and which could obviously maintain the liposomal vesicle size in fetal bovine serum. According to TEM and AFM, the phenomena of membrane fusion and deformation were observed respectively in ergosterol-incorporated liposomes. Results of fluorescence probe spectra revealed the most compact membrane structure was found in cholesterol-incorporated liposomes, which was in accordance with the strongest intermolecular interaction in bilayers obtained by FTIR results. Conversely, the membrane of ergosterol-incorporated liposomes was the most fragile and fluid, which was also identified with the lowest physical stability obtained by Turbiscan. These results systematically illustrated the relationship between the structure of sterols and the liposomal membrane stability, and provided some meaningful information on the choice of sterols and lecithin in preparation of liposomes for different purposes.

Preparation and characterization of an electrospun colon-specific delivery system for salmon calcitonin

A novel electrospun colon-specific delivery system for salmon calcitonin (SCT) was developed to improve its stability and bioavailability. Firstly, the pectin-coated SCT liposomes were prepared by film dispersion method and then a liposomes/sodium alginate/polyvinyl alcohol fiber mat was fabricated by electrospining. Scanning electron microscopy analysis indicated that the obtained nanofibers were uniform and smooth with an average diameter of about 350 nm. The release of SCT in different simulated digestive fluids was studied and corresponding release kinetics models were built. It was found that the fiber mat containing pectin-coated SCT liposomes had better stability and colon-specific properties compared with that containing uncoated SCT liposomes and the release of SCT in the colon followed the case II transport mechanism. In addition, there is no significant change in the bioactivity of released SCT measured by ELISA. This study shows that the electrospun colon-specific fiber mat is a potential delivery system for bioactive peptides.

The electrospun colon-specific fiber mat is a promising delivery system for SCT.

Encapsulation of phytosterols and phytosterol esters in liposomes made with soy phospholipids by high pressure homogenization

Phytosterols and phytosterol esters were encapsulated within large unilamellar liposomes prepared with soy phospholipids using a microfluidizer. The average particle diameter of these liposomal vesicles increased with increasing amounts of encapsulated phytosterols, especially with increasing free sterol content. The phytosterol content, liposomal particle size, and phytosterol encapsulation efficiency started to plateau when liposomes were prepared with MOPS buffer dispersions that contained 50 mg ml-1 soy phospholipid and more than 4% phytosterol blend, suggesting the saturation of phytosterol encapsulation. We proposed an encapsulation mechanism of free sterols and phytosterol esters in liposomes, where free sterols were mainly encapsulated within the lumen of these liposomes as crystals, and sterol esters and some free sterols were incorporated within the phospholipid bilayer of the liposomal membrane. The results from this work could provide the pharmaceutical and nutraceutical industries a practical method to produce loaded liposomes using inexpensive phospholipid mixtures for the delivery of bioactive ingredients.

Manufacture and Incorporation of Liposome-Entrapped Ethylenediaminetetraacetic Acid into Model Miniature Gouda-Type Cheese and Subsequent Effect on Starter Viability, pH, and Moisture Content

Liposome-encapsulated ethylenediaminetetraacetic acid (EDTA) was incorporated into a model miniature Gouda-type cheese (20 g) in order to assess its effect on rennet gelation, starter viability, pH, and moisture content. EDTA was encapsulated within 2 different food-grade proliposome preparations, Pro-Lipo Duo and Pro-Lipo C (50% and 40% unsaturated soybean phospholipids and 50% and 60% aqueous medium, respectively), using the following high-shear technologies: Ultra-Turrax (5000 rpm), 2-stage homogenization (345 bar), or microfluidization (690 bar). Liposome size distribution was affected by the high-shear technology employed with the proportion of large vesicles (>100 nm) decreasing in the order microfluidization < 2-stage homogenization < Ultra-Turrax. All EDTA-containing liposomes were stable during 28 d refrigerated storage, with no significant (P ≤ 0.05) change in size distribution or EDTA entrapment efficiency (%EE). Liposome composition affected the entrapment of EDTA, with Pro-Lipo C having a significantly greater %EE than Pro-Lipo Duo, 63% and 54%, respectively. For this reason, Pro-Lipo C EDTA liposomes, with and without EDTA, were incorporated into model miniature Gouda-type cheese. Addition of liposome-encapsulated EDTA to milk during cheese making did not impact pH or rennet gel formation. No differences in composition or pH were evident in liposome-treated cheeses. The results of this study show that the incorporation of liposome-encapsulated EDTA into milk during cheese manufacture did not affect milk fermentation, moisture content, or pH, suggesting that this approach may be suitable for studying the effects of calcium equilibrium on the texture of brine-salted cheeses.

Effect of Phytosterols on the Crystallization Behavior of Oil-in-Water Milk Fat Emulsions

Milk has been used commercially as a carrier for phytosterols, but there is limited knowledge on the effect of added plant sterols on the properties of the system. In this study, phytosterols dispersed in milk fat at a level of 0.3 or 0.6% were homogenized with an aqueous dispersion of whey protein isolate (WPI). The particle size, morphology, ζ-potential, and stability of the emulsions were investigated. Emulsion crystallization properties were examined through the use of differential scanning calorimetry (DSC) and Synchrotron X-ray scattering at both small and wide angles. Phytosterol enrichment influenced the particle size and physical appearance of the emulsion droplets, but did not affect the stability or charge of the dispersed particles. DSC data demonstrated that, at the higher level of phytosterol addition, crystallization of milk fat was delayed, whereas, at the lower level, phytosterol enrichment induced nucleation and emulsion crystallization. These differences were attributed to the formation of separate phytosterol crystals within the emulsions at the high phytosterol concentration, as characterized by Synchrotron X-ray measurements. X-ray scattering patterns demonstrated the ability of the phytosterol to integrate within the milk fat triacylglycerol matrix, with a concomitant increase in longitudinal packing and system disorder. Understanding the consequences of adding phytosterols, on the physical and crystalline behavior of emulsions may enable the functional food industry to design more physically and chemically stable products.

Optimization of Preparation Conditions for Lysozyme Nanoliposomes Using Response Surface Methodology and Evaluation of Their Stability

The main purpose of this study was to optimize the preparation of lysozyme nanoliposomes using response surface methodology and measure their stability. The stabilities of lysozyme nanoliposomes in simulated gastrointestinal fluid (SGF), simulated intestinal fluid (SIF), as well as pH, temperature and sonication treatment time were evaluated. Reverse-phase evaporation method is an easy, speedy, and beneficial approach for nanoliposomes’ preparation and optimization. The optimal preparative conditions were as follows: phosphatidylcholine-to-cholesterol ratio of 3.86, lysozyme concentration of 1.96 mg/mL, magnetic stirring time of 40.61 min, and ultrasound time of 14.15 min. At the optimal point, encapsulation efficiency and particle size were found to be 75.36% ± 3.20% and 245.6 nm ± 5.2 nm, respectively. The lysozyme nanoliposomes demonstrated certain stability in SGF and SIF at a temperature of 37 °C for 4 h, and short sonication handling times were required to attain nano-scaled liposomes. Under conditions of high temperature, acidity and alkalinity, lysozyme nanoliposomes are unstable.

Ion-pair amphiphile: a neoteric substitute that modulates the physicochemical properties of biomimetic membranes

Ion-pair amphiphiles (IPAs) are neoteric pseudo-double-tailed compounds with potential as a novel substitute of phospholipid. IPA, synthesized by stoichiometric/equimolar mixing of aqueous solution of hexadecyltrimethylammonium bromide (HTMAB) and sodium dodecyl sulfate (SDS), was used as a potential substituent of naturally occurring phospholipid, soylecithin (SLC). Vesicles were prepared using SLC and IPA in different ratios along with cholesterol. The impact of IPA on SLC was examined by way of surface pressure (π)-area (A) measurements. Associated thermodynamic parameters were evaluated; interfacial miscibility between the components was found to depend on SLC/IPA ratio. Solution behavior of the bilayers, in the form of vesicles, was investigated by monitoring the hydrodynamic diameter, zeta potential, and polydispersity index over a period of 100 days. Size and morphology of the vesicles were also investigated by electron microscopic studies. Systems comprising 20 and 40 mol % IPA exhibited anomalous behavior. Thermal behavior of the vesicles, as scrutinized by differential scanning calorimetry, was correlated with the hydrocarbon chain as well as the headgroup packing. Entrapment efficiency (EE) of the vesicles toward the cationic dye methylene blue (MB) was also evaluated. Vesicles were smart enough to entrap the dye, and the efficiency was found to vary with IPA concentration. EE was found to be well above 80% for some stable dispersions. Such formulations thus could be considered to have potential as novel drug delivery systems.