Characteristics of liposomes derived from egg yolk
Open Chemistry
Abstract and Figures
Liposomes are nanocapsules successfully applied in pharmacy and medicine. Their usage in the food industry could be increased by the development of alternative, cost-efficient lecithin materials. This work is a continuation of the previous two papers describing five different extractions of egg yolk lecithins and the pre-assessment of their usefulness for liposome formation. Physicochemical properties of extracts differed due to distinct composition. The aim of this research was to further characterise the extracts-based liposomes, especially in terms of nanomechanical properties and structural diversity. Five previously described extracts were used for liposomes preparation employing Bangham technique. Vesicles were analysed with the use of dynamic light scattering, flow cytometry, and atomic force microscopy. The results were tested for correlation with the composition of the extracts. It was proved that the chemical composition of the shell-forming material determined the size, structure, stability, and mechanical properties of the vesicles. The observed effects were found to result not only from differences in the content of major components, i.e. phospholipids, acylglycerols, and cholesterol, but also in the relative proportions. Minor constituents, i.e. tocopherols and carotenoids, were also found to be of significance. Strong correlations between size and Zeta potential of the vesicles with the content of carotenoids were determined.
![Dynamic light scattering and Zeta potential of liposomes measured directly after preparation: (a) Z-average size [nm]; (b) Zeta potential [mV]; (c) PDI. Bars bearing different superscripts are statistically, significantly different (α<0.05).](https://www.researchgate.net/profile/Grazyna-Lewandowicz/publication/336070024/figure/fig1/AS:11431281123064450@1677607641468/Dynamic-light-scattering-and-Zeta-potential-of-liposomes-measured-directly-after_Q320.jpg)
![Size distribution of MLV (a) and SUV (b) populations. Intensity [%] stands for intensity distribution - the 1st order result derived from dynamic light scattering measurement and represents the intensity distribution of particles sizes. The parameter is naturally weighted corresponding to the scattering intensity of each particle subpopulation/fraction.](https://www.researchgate.net/profile/Grazyna-Lewandowicz/publication/336070024/figure/fig2/AS:11431281123056139@1677607641557/Size-distribution-of-MLV-a-and-SUV-b-populations-Intensity-stands-for-intensity_Q320.jpg)
![Quantitative analysis of nanomechanical properties of SUV by FS: (a,b) illustrative scheme of the force spectroscopy experiment – force curve and indentation (I. – physical contact between AFM tip and surface of a vesicle, II. – indentation of a vesicle, III. – indentation of the mica substrate; symbols: z – scanner position, d – cantilever deflection, VD – cantilever deflection signal, h – height of vesicle, S – sensitivity, F – force); (c,d) typical approach (blue) – retraction (green) force curve recorded on a CE vesicle with calculated force [nN]; (d,e) the Johnson-Kendall-Roberts (JKR, red curve) model fitted to typical CE data region II. – force curve (d) and corresponding force-indentation profile (e); (f) scanning electron micrograph of Bruker DNP B tip after the experiment (cantilever no. 1, inset: radius R of the tip); (g,h) calculated Young’s modulus and adhesion force histograms for CE specimen (green striated curve – fitted Gauss distribution profile); (i) typical approach (blue) – retraction (green) force curve recorded on a H sample depicts indented lipid bilayer patch (region II.).](https://www.researchgate.net/profile/Grazyna-Lewandowicz/publication/336070024/figure/fig5/AS:11431281123035651@1677607642110/Quantitative-analysis-of-nanomechanical-properties-of-SUV-by-FS-a-b-illustrative_Q320.jpg)
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... Many articles in the literature reported the use of phospholipids from egg yolks to formulate liposomes [40][41][42]. The various composition and origin of egg yolk extract allows us to obtain liposomes with different characteristics and properties in terms of stability, permeability, and morphology [42,67,68]. ...
... Overall liposomes from compounds derived from Novel Foods originate from the hydration of thin lipid films or lipid cakes, causing them to expand. During agitation, the hydrated lipid sheets detach and naturally reseal themselves, leading to the creation of large liposomes that necessitate the input of energy, typically in the form of sonic energy (sonication) or mechanical energy (extrusion) for reducing size [39][40][41][42]67,68]. ...
Novel Food is a new category of food, regulated by the European Union Directive No. 2015/2283. This latter norm defines a food as “Novel” if it was not used “for human consumption to a significant degree within the Union before the date of entry into force of that regulation, namely 15 May 1997”. Recently, Novel Foods have received increased interest from researchers worldwide. In this sense, the key areas of interest are the discovery of new benefits for human health and the exploitation of these novel sources of materials in new fields of application. An emerging area in the pharmaceutical and medicinal fields is nanotechnology, which deals with the development of new delivery systems at a nanometric scale. In this context, this review aims to summarize the recent advances on the design and characterization of nanodelivery systems based on materials belonging to the Novel Food list, as well as on nanoceutical products formulated for delivering compounds derived from Novel Foods. Additionally, the safety hazard of using nanoparticles in food products, i.e., food supplements, has been discussed in view of the current European regulation, which considers nanomaterials as Novel Foods.
... In addition, BHT modulated BDNF expression in the hippocampus by altering the levels of Bifidobacterium, Rhodobacter sphaeroides, Corynebacterium glutamicum, and Lactobacillus . Both lily and egg yolk were rich in beneficial components, so they can be consumed as medicines as well as daily diet (Kondratowicz et al. 2019;Yuan et al. 2019). Therefore, BHT can be considered as a potential dietary strategy for the prevention of depression. ...
Traditional Chinese medicine has a history of thousands of years with a profound understanding and treatment of nervous system diseases. Natural products with neuroprotective activity have become potential neuroprotective agents. This review summarized the natural products and Chinese medicine prescriptions frequently used for treating neurological disorders, discussed the relationship between their regulatory effect and gut-brain axis, in order to provide scientific basis for clinical application. 81 compounds and 10 Chinese medicine prescriptions were analyzed for their significant neuroprotective activities, which are mediated through the regulation of the gut-brain axis. These compounds were meticulously classified based on their chemical structures, encompassing flavonoids, terpenoids, phenylpropanoids, phenolics, alkaloids, and carbohydrates. Notably, terpenoids constituted the largest share of these compounds. The pharmacological potential of these compounds was predominantly characterized by their anti-depressive (38.4%), anti-Alzheimer’s disease (20.0%), anti-cognitive impairment (13.6%), and anti-Parkinson's disease activity (7.2%). The underlying mechanisms to treat neurological disorders by mediating the gut-brain axis are mainly through inhibiting nervous system inflammation, Aβ aggregation, neuronal damage and synaptic dysfunction, improving neurotransmitter system dysfunction, repairing intestinal mucosa and blood–brain barrier, regulating metabolism, immunity, and intestinal flora homeostasis. The Chinese natural medicines and prescriptions show promise in treating a range of neurological disorders, particularly in the treatment of depression, Alzheimer's disease, cognitive impairment, and Parkinson's disease by balancing the gut microbiome, which not only provide new insights into the complex mechanisms of action of these medicines but also hold the potential for developing innovative therapeutic strategies.
... Liposomes are generally obtained from phospholipids, both natural, such as egg or soy phosphatidylcholines, and synthetic, such as dialkyl or trialkyl lipids [64,65]. For this study, a natural phospholipid (egg yolk phospholipids) was used because natural phospholipids, compared to synthetic ones, are available on a wider scale and can be purchased at a lower cost [66]. ...
Liposomes are intensively used as nanocarriers for biology, biochemistry, medicine, and in the cosmetics industry and their non-toxic and biocompatible nature makes these vesicles attractive systems for biomedical applications. Moreover, the conjugation of specific ligands to liposomes increases their cellular uptake and therapeutic efficiency. Considering these aspects, the aim of the present study was to obtain new formulations of cationic liposomes coated with dual-peptide functionalized carboxymethyl chitosan (CMCS) for the treatment of inner ear diseases. In order to achieve efficient active targeting and ensuring a high efficacy of the treatment, CMCS was functionalized with Tet1 peptide, to target specific ear cells, and TAT peptide, to ensure cellular penetration. Furthermore, dexamethasone phosphate was loaded as a model drug for the treatment of ear inflammation. The infrared spectroscopy confirmed the functionalization of CMCS with the two specific peptides. The mean diameter of the uncovered liposomes varied between 167 and 198 nm whereas the CMCS-coated liposomes ranged from 179 to 202 nm. TEM analysis showed the spherical shape and unilamellar structure of liposomes. The release efficiency of dexamethasone phosphate after 24 h from the uncoated liposomes was between 37 and 40% and it appeared that the coated liposomes modulated this release. The obtained results demonstrated that the liposomes are hemocompatible since, for a tested concentration of 100 µg/mL, the liposome suspension had a lysis of erythrocytes lower than 2.5% after 180 min of incubation. In addition, the peptide-functionalized CMCS-coated liposomes induced a non-significant effect on the viability of normal V79-4 cells after 48 h, at the highest doses. Values of 71.31% were recorded (CLCP-1), 77.28% (CLCP-2) and 74.36% (CLCP-3), correlated with cytotoxic effects of 28.69%, 22.72%, and 25.64%.
... Phospholipases are water-soluble, and their activity is significantly enhanced at the water-lipid interface within an aqueous emulsion, where the lipids commonly form an aggregation state (micelle, bilayer vesicle, and hexagonal array) (Kondratowicz, Weiss, Juzwa, Majchrzycki, & Lewandowicz, 2019). As the reaction proceeds, the accumulation of the reaction products, LPL, and fatty acids generates compositional heterogeneities and phase separation when a critical mole fraction of the reaction product accumulates (Asturias, Pascolini, & Blasie, 1990;Burack, Dibble, & Biltonen, 1997;Burack, Yuan, & Biltonen, 1993;L. ...
Enzymatic hydrolysis of phospholipids is an important biological event in organisms that is also widely applied in the food industry. In situ nuclear magnetic resonance (NMR) is a powerful non-invasive technique for studying the mechanism of enzymatic reactions. However, their application in phospholipid hydrolysis is limited. In this study, we demonstrated that in a phospholipase A1 (PLA1)-catalysed 1,2-diacyl-sn-glycero-3-phosphocholine (POPC) hydrolysis system in an aqueous emulsion, the accumulation of POPC hydrolysates caused severe het-erogeneity, which significantly reduced the 1 H NMR spectral intensity and resolution. To overcome the sample heterogeneity, we used the intermolecular dipolar-interaction enhanced all lines-II (IDEAL-II) sequence to obtain one-dimensional (1D) high-resolution 1 H intermolecular double quantum coherence (iDQCs) NMR spectra through two-dimensional (2D) acquisition. These spectra enabled us to assign and trace the characteristic peaks of POPC and its hydrolysates in real time. In particular, we performed quantitative estimation of the reaction kinetics based on the g2 and g3 protons and provided direct evidence of the enzymatic hydrolysis process. This study not only fills the gap in 1D 1 H spectrum data of phospholipids and their mixtures with hydrolysates, but also provides an effective method for a comprehensive and rapid analysis of fatty acids and even more complex heterogeneous systems.
... Худалдаанд буй бор болон цагаан өндөгний Gladkowski [7][8][9][10] нарын арга зүйг мөрдлөг болгон шар хэсгээс фосфолипид ялган авав. Тосон болон хуурай хэлбэртэй зөөвөрлөгдөх бодисын липосомд холбогдох идэвхийг судлахдаа GE healthcare [10] арга зүйн дагуу хийж гүйцэтгэлээ. ...
Research on the use of liposomes as a carrier of bio-active compounds has been carried out extensively due to that liposome-carried drugs have more than 80% activity in reaching target cells. In this study, we conducted research on the possibility of using phospholipids to convert oil and water-insoluble compounds with biological activities into water-based compounds. This will allow to introduce the advancements in liposomal delivery of medicinal products practice of human medicine to the veterinary medicine as a promising approach. We prepared liposome extract from egg yolk, then 0.5 ml of 5% potassium-iodine and 0.3 g of cur cumin were transported to the liposome by ultra-sonication method. The measurements of an electron microscope at 500 nm indicate that a spherical phospholipids were formed successfully. As a result of FT-IR spectrophotometry, functional groups of fatty acids were detected at 3400 cm-1, C-H at 2973 cm-1, C=O at 1730 cm-1, and C-O at 1220 cm-1. The ratio of saturated and unsaturated fatty acids by gas chromatography (GC/MS) was 60.44% and 37.91% in white eggs, while 39.41% and 62.02% in brown eggs, respectively. Биологийн идэвхтэй нэгдлийг липосом ашиглан зөөвөрлөх боломж Хураангуй Липосомыг био-идэвхит нэгдлийн зөөвөрлөгч болгон ашиглах судалгаа өргөнөөр хийгдэж, шахмал эмийн үйлчлэх идэвх 20%, тарилга 70%-ийн идэвхтэй байдаг бол липосомоор зөөвөрлөгдсөн тэдгээр нэгдлийн бай эсэд хүрч очин 80-аас дээш хувийн идэвх үзүүлдэг байна. Бид энэхүү судалгаагаар липосом ашиглан тосон суурьт болон усанд уусдаггүй биологийн идэвхтэй нэгдлүүдийг зөөвөрлөх боломжийг судаллаа. Ингэснээр хүн эмнэлгийн анагаах ухаанд нэвтрээд буй липосом ашиглах аргыг мал эмнэлгийн хэрэглээнд нэвтрүүлэх боломж нээгдэх юм. Туршилтанд 0.5 мл 5%-ын кали-иодын тос ашиглан липосомоор зөөвөрлөх туршилтыг явуулахад уусмал нэгэн жигд хөөсөрсөн бол 0.3 г куркумин хуурай бодисны хувьд тунадас бага үүсгэж байсан нь липосомоор зөөвөрлөгдөх боломжтойг харуулж байна. Бүтцийн анализ хийсэн FT-IR спектрофотометрийн үр дүнд 3400 см-1 утганд –ОН групп, 2973 см-1 утганд С-Н, 1730 см-1 утганд С=О, 1220 см-1 утганд С-О тосны хүчлийн функциональ бүлгүүд илэрсэн. Электрон микроскопын 500 нм хэмжилтэд фосфолипид бөмбөлөг үүссэн нь липосом мөн болохыг илтгэж байна. Масс спектрийн хийн хроматографийн (GC/MS) аргаар ханасан болон ханаагүй тосны хүчлийн харьцааг тодорхойлоход цагаан өндгөнд 60.44% ба 37.91%, бор өндгөнд 39.41% ба 62.02% тус тус байв. Таньцын туршилтаар биологийн идэвхит нэгдлийг тээвэрлэх боломжтой нь тогтоогдлоо. Түлхүүр үг: Өндөгний шар, фосфолипид, липосом, тосон суурьт нэгдэл, куркумин
... The lipid components of the liposomes determine the rigidity, fluidity, and surface charge and, consequently, their ability to be loaded with bioactive compounds and release them [62]. For instance, the use of unsaturated lipids, such as phosphatidylcholines from natural sources (egg or soy lecithin), results in relatively permeable liposomes [63]. On the other hand, cholesterol molecules are also known to modulate membrane rigidity properties. ...
A recently synthesized new eugenol derivative, ethyl 4-(2-methoxy-4-(oxiran-2-ylmethyl)phenoxy)butanoate, with a high insecticidal activity against Sf9 (Spodoptera frugiperda) insect cells, was encapsulated in the liposomal formulations of egg-phosphatidylcholine/cholesterol (Egg-PC:Ch) 70:30 and 100% dioleoylphosphatidylglycerol (DOPG), aiming at the future application as insecticides. Compound-loaded DOPG liposomes have sizes of 274 ± 12 nm, while Egg-PC:Ch liposomes exhibit smaller hydrodynamic diameters (69.5 ± 7 nm), high encapsulation efficiency (88.8 ± 2.7%), higher stability, and a more efficient compound release, thus, they were chosen for assays in Sf9 insect cells. The compound elicited a loss of cell viability up to 80% after 72 h of incubation. Relevantly, nanoencapsulation maintained the toxicity of the compound toward insect cells while lowering the toxicity toward human cells, thus showing the selectivity of the system. Structure-based inverted virtual screening was used to predict the most likely targets and molecular dynamics simulations and free energy calculations were used to demonstrate that this molecule can form a stable complex with insect odorant binding proteins and/or acetylcholinesterase. The results are promising for the future application of compound-loaded nanoliposome formulations as crop insecticides.
Lipid nanoparticles (LNPs) have emerged as promising carriers for delivering therapeutic agents, including mRNA-based immunotherapies, in various biomedical applications. The use of LNPs allows for efficient delivery of drugs, resulting in enhanced targeted delivery to specific tissues or cells. These LNPs can be categorized into several types, including liposomes, solid lipid nanoparticles, nanostructured lipid carriers, and lipid-polymer hybrid nanoparticles. The preparation of LNPs involves the manipulation of their structural, dimensional, compositional, and physical characteristics via the use of different methods in the industry. Lipids used to construct LNPs can also be derived from various biological sources, such as natural lipids extracted from plants, animals, or microorganisms. This review dives into the different types of LNPs and their preparation methods. More importantly, it discusses all possible biological sources that are known to supply lipids for the creation of LNPs. Natural lipid reservoirs have surfaced as promising sources for generating LNPs. The use of LNPs in drug delivery is expected to increase significantly in the coming years. Herein, we suggest some environmentally friendly and biocompatible sources that can produce lipids for future LNPs production.
Compared with small-molecule synthetic drugs, bioactive peptides have desirable advantages in efficiency, selectivity, safety, tolerance, and side effects, which are accepted by attracting extensive attention from researchers in food, medicine, and other fields. However, unacceptable barriers, including mucus barrier, digestive enzyme barrier, and epithelial barrier, cause the weakening or the loss of bioavailability and biostability of bioactive peptides. The nanocarrier system for bioactive peptide delivery needs to be further probed. We provide a comprehensive update on the application of versatile delivery systems for embedding bioactive peptides, including liposomes, polymer nanoparticles, polysaccharides, hydrogels, and self-emulsifying delivery systems, and further clarify their structural characterization, advantages, and disadvantages as delivery systems. It aims to provide a reference for the maximum utilization of bioactive peptides. It is expected to be an effective strategy for improving the bioavailability and biostability of bioactive peptides.
About 9.6 million people died of cancer in 2018 according to the World Health Organization. Classical therapy involves the administration of natural molecules such as alkaloids, terpenes, purines, lactones, peptides, proteins, and macrocyclic polyethers isolated from plants and animals. However, classical treatments are limited by drug toxicity to healthy cells and chemo-resistance of cancer cells. This can be solved by site-specific delivery using polymeric nanoparticles as novel nanocargos of anticancer molecules. Advantages include better pharmacokinetics, less toxicity, and more permeation and retention of drugs at the tumor site. This chapter reviews the synthesis and applications of polymeric nanoparticles containing drugs and polymers of natural origin. Recent patents, regulatory compliance and marketed products are also discussed.
A full membrane fusion model which attains both complete lipid mixing and content mixing liposomal membranes mediated by coiled-coil forming lipopeptides LPK [L-PEG 12 -(KIAALKE) 3 ] and LPE [L-PEG 12 -(EIAALEK) 3 ] is presented. The electrostatic effects of lipid anchored peptides on fusion efficiency was investigated. For this, the original amino acid sequence of the membrane bound LPK was varied at its ‘f’-position of the helical structure, i.e. via mutating the anionic glutamate residues by either neutral serines or cationic lysines. Both CD and fluorescence measurements showed that replacing the negatively charged glutamate did not significantly alter the peptide ability to form a coiled coil, but lipid mixing and content mixing assays showed more efficient liposome-liposome fusion resulting in almost quantitative content mixing for the lysine mutated analogue ( LPK K ) in conjunction with LPE . A mechanism is proposed for a fusion model triggered by membrane destabilizing effects mediated by the membrane destabilizing activety of LPK in cooperation with the electrostatic activity of LPE . This new insight may enlightens the further development of a promising nano carrier tool for biomedical applications.
Egg yolk, due to its emulsifying properties has a long – term tradition in food technology applications. Additionally, egg yolk extracts obtained through simple procedures were proved to be an attractive alternative to highly purified phospholipids. The aim of this work was to analyse the interfacial behaviour of previously described extracts in relation to liposomes preparation. The extracts underwent analysis of surface properties: the π-A isotherm, dilatational and stress rheology experiments as well as surface potential analysis with the use of Langmuir trough. It was proved that EA, MA and HE films were characterized by the highest collapse pressure during compression, but revealed relatively large hysteresis, suggesting irreversibility. CE extract showed minor hysteresis and high reversibility of orientation changes. The most important factor determining the elastic response on area deformation is the content of phospholipids. The lysophosphatidylcholine/phospholipids ratio is also the important factor. The balance between polar and non-polar fraction of lipids and high content of phopsholipds fraction in the film are conducive for solid-like response on shear stress whereas the presence of lysophosphatidylethanolamine induce fluid-like behaviour of this complex film. Minor film constituents significantly affect properties of the film too. MA and EA extracts revealed the highest similarity. CE and HE extracts also showed significant similarity to each other, whereas H extract differed from each.
Atomic force microscopy (AFM) is one of the most commonly used scanning probe microscopy techniques for nanoscale imaging and characterization of lipid-based particles. However, obtaining images of such particles using AFM is still a challenge. The present study extends the capabilities of AFM to the characterization of proteoliposomes, a special class of liposomes composed of lipids and proteins, mimicking matrix vesicles (MVs) involved in the biomineralization process. To this end, proteoliposomes were synthesized, composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phospho-L-serine (DPPS), with inserted tissue-nonspecific alkaline phosphatase (TNAP) and/or annexin V (AnxA5), both characteristic proteins of osteoblast-derived MVs. We then aimed to study how TNAP and AnxA5 insertion affects the proteoliposomes' membrane properties and, in turn, interactions with type II collagen, thus mimicking early MV activity during biomineralization. AFM images of these proteoliposomes, acquired in dynamic mode, revealed the presence of surface protrusions with distinct viscoelasticity, thus suggesting that the presence of the proteins induced local changes in membrane fluidity. Surface protrusions were measurable in TNAP-proteoliposomes but barely detectable in AnxA5-proteoliposomes. More complex surface structures were observed for proteoliposomes harboring both TNAP and AnxA5 concomitantly, resulting in a lower affinity for type II collagen fibers compared to proteoliposomes harboring AnxA5 alone. The present study achieved the topographic analysis of lipid vesicles by direct visualization of structural changes, resulting from protein incorporation, without the need for fluorescent probes.
The aim of this study was the assessment of the physicochemical stability of D-α-tocopherol formulated in medium chain triglyceride nanoemulsions, stabilized with Tween®80 and Lipoid®S75 as surfactant and co-surfactant, respectively. D-α-Tocopherol was selected as active ingredient because of its well-recognised interesting anti-oxidant properties (as radical scavenger) for food and pharmaceutical industries. A series of nanoemulsions of mean droplet size below 90 nm (polydispersity index < 0.15) have been produced by high-pressure homogenization, and their surface electrical charge (zeta potential), pH, surface tension, osmolarity, and rheological behavior, were characterized as a function of the D-α-tocopherol loading. In vitro studies in Caco-2 cell lines confirmed the safety profile of the developed nanoemulsions with percentage of cell viability above 90% for all formulations.
The physicochemical properties of large unilamellar vesicles (LUVs) were assessed with respect to lipid composition, pH, time, and temperature by monitoring their size, zeta potential, drug payload, and thermal behavior. A conventional thin film hydration technique was employed to prepare liposomes from soy phosphatidylcholine (SPC), dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG), and a 7:3 (M/M) mixture of DPPC+DPPG along with 30 mole% cholesterol in each combination. While the size of liposomes depended on lipid composition, pH and temperature, the zeta potential was found to be independent of the pH of the medium, although it varied with liposome type. Spherical morphology and bilayer were observed by electron microscopy. The phase transition temperature increased with decreasing pH. Membrane micro-viscosity showed the highest value for SPC, and membrane rigidity increased with increasing pH. The entrapment efficiency of liposomes with reference to curcumin was as follows: DPPC＞DPPC+DPPG＞DPPG＞SPC. Sustained release of curcumin was observed for all liposomes. Curcumin-loaded liposomes exhibited substantial antibacterial activity against the gram-positive bacteria Bacillus amyloliquefaciens. Additional studies are needed to improve the understanding of the effect of formulation variables on the physicochemical stability of liposomes.
Liposomes are attractive encapsulation systems that provide enhanced stability of encapsulated materials against a range of environmental, enzymatic, and chemical stresses, including the presence of enzymes or reactive chemicals, and exposure to extreme pH, temperature, and ionic strength changes. Liposomes have been widely used in the pharmaceutical and food industries because of their biocompatibility, biodegradability, absence of toxicity, small size, and ability to carry a wide variety of bioactive compounds due to the amphiphilicity of the phospholipid encapsulating material. In the food industry, liposomes have recently been used to deliver different functional compounds in food systems. In this paper, the food application of liposomes and nanoliposomes as emerging carrier vehicles of vitamins, enzymes, food antimicrobials, essential oils, and polyphenols is discussed in detail.
This work presents unprecedented AFM images of Na,K-ATPase (NKA) pump after reconstituted into DPPC and DPPC:DPPE liposomes. The mechanical properties observed in phase images were associated with protrusions correlated to NKA microdomains, areas seen darker in the AFM phase images. Protrusions in DPPC-NKA-proteoliposomes ranged from 38 to 115 nm, with 74 ± 21 nm in diameter and 2.1 ± 1.4 nm in height. DPPC:DPPE-NKA-proteoliposomes showed protrusions from 21 to 78 nm, with 38 ± 16 nm in diameter and 0.7 ± 0.5 nm in height. We have estimated the presence of anullar lipids in the microdomains considering that the areas of the protrusions should contain αβ oligomers and annular phospholipids. For DPPC-NKA-proteoliposomes, the hypothesis consists in 40 phospholipids surrounding an (αβ)2 dimer, and, 46 phospholipids for DPPC:DPPE-NKA-proteoliposomes in an αβ monomer. Catalytic activity measurements of both lipid compositions of proteoliposomes harboring NKA provide strong evidences regarding the protein orientation into the biomembrane. AFM data suggests that DPPC-NKA-proteoliposomes are also rightside-out protein orientated , with the protrusions average height of 2.1 nm, whilst for DPPC:DPPE-NKA-proteoliposomes, the majority of the protein reconstituted should be inside-out orientated, with the protrusions average height of 0.5 nm, corroborating with the enzymatic analysis, where 61% and 91% of the enzymatic activity was recovered, respectively. Thus, a new application of AFM as a tool for determination of topological features of protrusions in proteoliposomes has been brought to the scientific community, relating also to the determination of distinct catalytic orientation of enzymes present in the biomembranes model.
Our aim was to propose simple extraction process to obtain phospholipids along with yolk‐derived vitamins and fats. Five extracts marked as ethanol/acetone, methanol‐chloroform/acetone, hot ethanol, hexane, and cold ethanol were developed and compared. Extracts' compositions were analyzed in terms of phospholipid, polar and nonpolar fraction, cholesterol, carotenoids, and tocopherols content. Further, liposomes prepared from extracts were characterized. The highest extraction efficiency was achieved by a one‐step hexane procedure. However, that sample, in contrast to the other four extracts, revealed distinctively lower permeability when used for liposomes membrane formation. Principal component analysis proved that major components contents were decisive for liposomes membranes permeability, whereas minor constituents’ content controlled zeta potential and Z‐average size.
Practical Application
Liposomes are nanocarriers widely used in pharmaceutical industry. Due to intravenous route of administration, they have to be produced from phospholipids of very fine purity. On the other hand, there is increasing interest in nanoencapsulation of labile, bioactive substances for manufacturing of health promoting food. Unfortunately, high‐price pure phospholipids are prohibitive for food applications. The use of raw material obtained by simple extraction procedure instead of highly purified phospholipids could be an attractive alternative for food industry.
Solid lipid nanoparticle (SLN), nanostructured lipid carriers (NLC) and hybrid nanoparticles, have gained increasing interest as drug delivery systems because of their potential to load and release drugs from the Biopharmaceutical classification system (BCS) of class II (low solubility and high permeability) and of class IV (low solubility and low permeability). Lipid properties (e.g. high solubilizing potential, biocompatibility, biotolerability, biodegradability and distinct route of absorption) contribute for the improvement of the bioavailability of these drugs for a set of administration routes. Their interest continues to grow, as translated by the number of patents being field worldwide. This paper discusses the recent advances on the use of SLN, NLC and lipid-polymer hybrid nanoparticles for the loading of lipophilic, poorly water-soluble and poorly permeable drugs, being developed for oral, topical, parenteral and ocular administration, also discussing the industrial applications of these systems. A review of the patents filled between 2014 and 2017, concerning the original inventions of lipid nanocarriers, is also provided.
Background:
Liposomes are promising carriers for drugs and bioactive compounds. Size and structure are their crucial parameters. Thus, it is essential to assess individual vesicles as prepared. Currently available techniques fail to measure liposome's size and structure simultaneously, with a high throughput. To solve this problem, we have developed a novel, flow cytometric method quantifying liposomes.
Methods:
Firstly, the following fluorescent staining combinations were tested: DiD/TO, Rh123/DiD, Syto9/DiD. Further, chosen fluorochromes were used to compare three populations of vesicles: raw (R), obtained by thin film hydration and extruded ones (populations E10 and E21). Dynamic light scattering (DLS) was used for determination of average diameter and size distribution of nanocarriers. Structural differences between the raw and the extruded liposomes, as well as additional information concerning vesicles size were acquired employing atomic force microscopy (AFM).
Results:
DLS analysis indicated that, three distinct populations of vesicles were obtained. Liposomes were characterized by mean diameter of 323nm, 220nm and 170nm for population R, E10 and E21 respectively. All the populations were stable and revealed zeta potential of - 29mV. AFM confirmed that raw and extruded liposomes were differed in structure.
Conclusions and general significance:
DiD/TO was the optimal fluorochrome combination that enabled to resolve distinctly the sub-populations of liposomes. Results obtained by flow cytometry were in a good agreement with those from DLS and AFM. It was proved that, flow cytometry, when proper fluorescent dyes are used, is an adequate method for liposomes assessment. The proposed method enables fast and reliable analysis of liposomes in their native environment.