Artificial Models of Biological Membranes

A special issue of Membranes (ISSN 2077-0375). This special issue belongs to the section "Biological Membrane Dynamics and Computation".

Deadline for manuscript submissions: closed (10 July 2023) | Viewed by 53481

Special Issue Editor

Laboratory for biophysics and medical physics, Department of medical physics and biophysics, University of Split School of Medicine, Split, Croatia
Interests: artificial biological membranes; fiber cell plasma membranes; cholesterol; cholesterol bilayer domain; discrimination of lipid domains; biophysical methods
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Artificial membranes are used extensively as models that mimic cell membranes. In this research area a great deal of evidence suggests positive functions of high membrane cholesterol levels in some membranes (eye lens) while as proposed by others, serve as a sign of pathology in other membranes (e.g. atherosclerosis). Improvement of methodology for formation of model membrane bilayers, especially of these with high cholesterol content is desirable and significant.

This Special Issue aims to provide improved protocols for preparations of artificial membranes that can be used as better models for studying structure, dynamics and properties of biological membranes using different fluorescent and microscopy methods, electron paramagnetic or nuclear magnetic resonance, calorimetry, x-ray diffraction etc.

In this Special Issue we invite you to submit your research articles and reviews. Research areas may include (but are not limited to) the following topics related to artificial membranes:

  • Development and testing methods for preparation of artificial membranes with a different cholesterol contents (e.g. giant unilamellar vesicles or supported single membrane bilayers)
  • Investigating the lateral organization and dynamics of lipids in artificial and biological membranes with special attention to domain formation
  • Interactions and assemblies of molecules in the membrane, such as cholesterol, phospholipids, sphingolipids, and proteins

We look forward to receiving and publishing your contributions.

Sincerely,

Prof. Dr. Marija Raguž
Guest Editor

Manuscript Submission Information

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Keywords

  • phospholipids
  • sphingolipids
  • cholesterol
  • lipid composition
  • rafts
  • cholesterol bilayer domain
  • artificial membranes
  • membrane domains
  • biophysical methods

Published Papers (26 papers)

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17 pages, 5044 KiB  
Article
Optical Properties and Interference Effects of the Lens Mitochondrion
by Felix Margadant, Zakaria Almsherqi, Xiaochun Xu and Yuru Deng
Membranes 2023, 13(6), 610; https://doi.org/10.3390/membranes13060610 - 20 Jun 2023
Viewed by 1321
Abstract
The lens mitochondrion of the tree shrew, located along the optical pathway between the lens and photoreceptors, has been investigated. The results suggest that the lens mitochondrion acts as a quasi-bandgap or imperfect photonic crystal. Interference effects cause a shift in the focus [...] Read more.
The lens mitochondrion of the tree shrew, located along the optical pathway between the lens and photoreceptors, has been investigated. The results suggest that the lens mitochondrion acts as a quasi-bandgap or imperfect photonic crystal. Interference effects cause a shift in the focus and introduce wavelength-dependent behavior similar to dispersion. Optical channels within the mitochondrion form a mild waveguide, preferentially propagating light within certain compartments. The lens mitochondrion also functions as an imperfect UV-shielding interference filter. Overall, this study provides insights into the dual role of the lens mitochondrion and the complex behavior of light within biological systems. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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23 pages, 5631 KiB  
Article
Structural Impact of Selected Retinoids on Model Photoreceptor Membranes
by Szymon Radzin, Anna Wiśniewska-Becker, Michał Markiewicz, Sebastian Bętkowski, Justyna Furso, Joanna Waresiak, Jarosław Grolik, Tadeusz Sarna and Anna M. Pawlak
Membranes 2023, 13(6), 575; https://doi.org/10.3390/membranes13060575 - 01 Jun 2023
Cited by 2 | Viewed by 1209
Abstract
Photoreceptor membranes have a unique lipid composition. They contain a high level of polyunsaturated fatty acids including the most unsaturated fatty acid in nature, docosahexaenoic acid (22:6), and are enriched in phosphatidylethanolamines. The phospholipid composition and cholesterol content of the subcellular components of [...] Read more.
Photoreceptor membranes have a unique lipid composition. They contain a high level of polyunsaturated fatty acids including the most unsaturated fatty acid in nature, docosahexaenoic acid (22:6), and are enriched in phosphatidylethanolamines. The phospholipid composition and cholesterol content of the subcellular components of photoreceptor outer segments enables to divide photoreceptor membranes into three types: plasma membranes, young disc membranes, and old disc membranes. A high degree of lipid unsaturation, extended exposure to intensive irradiation, and high respiratory demands make these membranes sensitive to oxidative stress and lipid peroxidation. Moreover, all-trans retinal (AtRAL), which is a photoreactive product of visual pigment bleaching, accumulates transiently inside these membranes, where its concentration may reach a phototoxic level. An elevated concentration of AtRAL leads to accelerated formation and accumulation of bisretinoid condensation products such as A2E or AtRAL dimers. However, a possible structural impact of these retinoids on the photoreceptor-membrane properties has not yet been studied. In this work we focused just on this aspect. The changes induced by retinoids, although noticeable, seem not to be significant enough to be physiologically relevant. This is, however, an positive conclusion because it can be assumed that accumulation of AtRAL in photoreceptor membranes will not affect the transduction of visual signals and will not disturb the interaction of proteins engaged in this process. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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6 pages, 1071 KiB  
Communication
Binding Behavior between Transforming-Growth-Factor-Beta1 and Its Receptor Reconstituted in Biomimetic Membranes
by Gounhanul Shin, Kunn Hadinoto, Sungmun Lee and Jin-Won Park
Membranes 2023, 13(4), 446; https://doi.org/10.3390/membranes13040446 - 19 Apr 2023
Cited by 1 | Viewed by 667
Abstract
Transforming growth factor β1 (TGF-β1) is critical to cell differentiation, proliferation, and apoptosis. It is important to understand the binding affinity between TGF-β1 and its receptors. In this study, their binding force was measured using an atomic force microscope. Significant adhesion was induced [...] Read more.
Transforming growth factor β1 (TGF-β1) is critical to cell differentiation, proliferation, and apoptosis. It is important to understand the binding affinity between TGF-β1 and its receptors. In this study, their binding force was measured using an atomic force microscope. Significant adhesion was induced by the interaction between the TGF-β1 immobilized on the tip and its receptor reconstituted in the bilayer. Rupture and adhesive failure occurred at a specific force around 0.4~0.5 nN. The relationship of the force to loading rate was used to estimate the displacement where the rupture occurred. The binding was also monitored in real time with surface plasmon resonance (SPR) and interpreted with kinetics to acquire the rate constant. Using the Langmuir adsorption, the SPR data were analyzed to estimate equilibrium and association constants to be approximately 107 M−1 and 106 M−1 s−1. These results indicated that the natural release of the binding seldom occurred. Furthermore, the degree of binding dissociation, confirmed by the rupture interpretation, supported that the reverse of the binding hardly happened. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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12 pages, 4069 KiB  
Article
Electroformation of Giant Unilamellar Vesicles from Damp Lipid Films Formed by Vesicle Fusion
by Zvonimir Boban, Ivan Mardešić, Sanja Perinović Jozić, Josipa Šumanovac, Witold Karol Subczynski and Marija Raguz
Membranes 2023, 13(3), 352; https://doi.org/10.3390/membranes13030352 - 18 Mar 2023
Cited by 1 | Viewed by 2114
Abstract
Giant unilamellar vesicles (GUVs) are artificial membrane models which are of special interest to researchers because of their similarity in size to eukaryotic cells. The most commonly used method for GUVs production is electroformation. However, the traditional electroformation protocol involves a step in [...] Read more.
Giant unilamellar vesicles (GUVs) are artificial membrane models which are of special interest to researchers because of their similarity in size to eukaryotic cells. The most commonly used method for GUVs production is electroformation. However, the traditional electroformation protocol involves a step in which the organic solvent is completely evaporated, leaving behind a dry lipid film. This leads to artifactual demixing of cholesterol (Chol) in the form of anhydrous crystals. These crystals do not participate in the formation of the lipid bilayer, resulting in a decrease of Chol concentration in the bilayer compared to the initial lipid solution. We propose a novel electroformation protocol which addresses this issue by combining the rapid solvent exchange, plasma cleaning and spin-coating techniques to produce GUVs from damp lipid films in a fast and reproducible manner. We have tested the protocol efficiency using 1/1 phosphatidylcholine/Chol and 1/1/1 phosphatidylcholine/sphingomyelin/Chol lipid mixtures and managed to produce a GUV population of an average diameter around 40 µm, with many GUVs being larger than 100 µm. Additionally, compared to protocols that include the dry film step, the sizes and quality of vesicles determined from fluorescence microscopy images were similar or better, confirming the benefits of our protocol in that regard as well. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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17 pages, 2761 KiB  
Article
Quantification of Age-Related Changes in the Lateral Organization of the Lipid Portion of the Intact Membranes Isolated from the Left and Right Eye Lenses of the Same Human Donor
by Laxman Mainali, Marija Raguz and Witold Karol Subczynski
Membranes 2023, 13(2), 189; https://doi.org/10.3390/membranes13020189 - 03 Feb 2023
Viewed by 1266
Abstract
The continuous wave EPR spin-labeling method was used to evaluate age-related changes in the amounts of phospholipids (PLs) and cholesterol (Chol) in domains present in intact, cortical, and nuclear fiber cell plasma membranes isolated separately from the left and right eye lenses of [...] Read more.
The continuous wave EPR spin-labeling method was used to evaluate age-related changes in the amounts of phospholipids (PLs) and cholesterol (Chol) in domains present in intact, cortical, and nuclear fiber cell plasma membranes isolated separately from the left and right eye lenses of the same human donor. The relative amounts of boundary plus trapped PLs were evaluated with the PL analog 12-doxylstearic acid spin label (12-SASL) and the relative amounts of trapped Chol with the Chol analog androstane spin label (ASL). The donors ranged in age from 15 to 70 years. Both the left and right eye lenses from donors aged 60, 65, and 70 years had nuclear cataracts; additionally, the right eye lens only of the 60-year-old donor had a cortical cataract. In transparent lenses, the relative amounts of boundary plus trapped PLs increase monotonously with donor age, and, at all ages, this amount was greater in nuclear compared with cortical membranes. Moreover, in transparent lenses, the relative amount of trapped Chol increases with age in nuclear membranes. However, the EPR spectrum of ASL from cortical membranes of 15- to 60-year-old donors shows only the weakly immobilized component assigned to ASL in the bulk plus Chol bilayer domain. Only the cortical membranes of 61- to 70-year-old donors contain both weakly and strongly immobilized components. The strongly immobilized component is assigned to ASL in trapped lipids. We speculate that the age of 60 years may be considered as a “threshold” for appearance of trapped lipids in cortical membranes. The relative amounts of boundary plus trapped PLs in lenses with nuclear cataracts is lower than that predicted from the tendency of the age-dependent increase observed for transparent lenses. The differences in amounts of lipids in the indicated left and right eye domains of each donor are smaller than the differences in single donors of a similar age. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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16 pages, 2423 KiB  
Article
Biomimetic Stratum Corneum Liposome Models: Lamellar Organization and Permeability Studies
by Susmita Roy, James C. S. Ho, Douglas L. C. Teo, Shikhar Gupta and Madhavan Nallani
Membranes 2023, 13(2), 135; https://doi.org/10.3390/membranes13020135 - 20 Jan 2023
Cited by 2 | Viewed by 2435
Abstract
The stratum corneum (SC), the outer layer of the skin, plays a crucial role as a barrier protecting the underlying cells from external stress. The SC comprises three key components: ceramide (CER), free fatty acid (FFA), and cholesterol, along with small fractions of [...] Read more.
The stratum corneum (SC), the outer layer of the skin, plays a crucial role as a barrier protecting the underlying cells from external stress. The SC comprises three key components: ceramide (CER), free fatty acid (FFA), and cholesterol, along with small fractions of cholesterol sulfate and cholesterol ester. In order to gain a deeper understanding about the interdependence of the two major components, CER and FFA, on the organizational, structural, and functional properties of the SC layer, a library of SC lipid liposome (SCLL) models was developed by mixing CER (phytosphingosine or sphingosine), FFA (oleic acid, palmitic acid, or stearic acid), cholesterol, and cholesterol sulfate. Self-assembly of the SC lipids into lamellar phases was first confirmed by small-angle X-ray scattering. Short periodicity and long periodicity phases were identified for SCLLs containing phytosphingosines and sphingosine CERs, respectively. Furthermore, unsaturation in the CER acyl and FFA chains reduced the lipid conformational ordering and packing density of the liposomal bilayer, which were measured by differential scanning calorimetry and Fourier transform infrared spectroscopy. The introduction of unsaturation in the CER and/or FFA chains also impacted the lamellar integrity and permeability. This extensive library of SCLL models exhibiting physiologically relevant lamellar phases with defined structural and functional properties may potentially be used as a model system for screening pharmaceuticals or cosmetic agents. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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22 pages, 1978 KiB  
Article
Lamellarity-Driven Differences in Surface Structural Features of DPPS Lipids: Spectroscopic, Calorimetric and Computational Study
by Lea Pašalić, Barbara Pem and Danijela Bakarić
Membranes 2023, 13(1), 83; https://doi.org/10.3390/membranes13010083 - 09 Jan 2023
Cited by 7 | Viewed by 1803
Abstract
Although single-lipid bilayers are usually considered models of eukaryotic plasma membranes, their research drops drastically when it comes to exclusively anionic lipid membranes. Being a major anionic phospholipid in the inner leaflet of eukaryote membranes, phosphatidylserine-constituted lipid membranes were occasionally explored in the [...] Read more.
Although single-lipid bilayers are usually considered models of eukaryotic plasma membranes, their research drops drastically when it comes to exclusively anionic lipid membranes. Being a major anionic phospholipid in the inner leaflet of eukaryote membranes, phosphatidylserine-constituted lipid membranes were occasionally explored in the form of multilamellar liposomes (MLV), but their inherent instability caused a serious lack of efforts undertaken on large unilamellar liposomes (LUVs) as more realistic model membrane systems. In order to compensate the existing shortcomings, we performed a comprehensive calorimetric, spectroscopic and MD simulation study of time-varying structural features of LUV made from 1,2-dipalmitoyl-sn-glycero-3-phospho-L-serine (DPPS), whereas the corresponding MLV were examined as a reference. A substantial uncertainty of UV/Vis data of LUV from which only Tm was unambiguously determined (53.9 ± 0.8 °C), along with rather high uncertainty on the high-temperature range of DPPS melting profile obtained from DSC (≈50–59 °C), presumably reflect distinguished surface structural features in LUV. The FTIR signatures of glycerol moiety and those originated from carboxyl group serve as a strong support that in LUV, unlike in MLV, highly curved surfaces occur continuously, whereas the details on the attenuation of surface features in MLV were unraveled by molecular dynamics. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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14 pages, 1711 KiB  
Article
On the Permeation of Polychlorinated Dibenzodioxins and Dibenzofurans through Lipid Membranes: Classical MD and Hybrid QM/MM-EDA Analysis
by Raúl Alvarado, Gustavo Cárdenas, Juan J. Nogueira, Nicolás Ramos-Berdullas and Marcos Mandado
Membranes 2023, 13(1), 28; https://doi.org/10.3390/membranes13010028 - 25 Dec 2022
Cited by 1 | Viewed by 1776
Abstract
The permeation of dioxin-like pollutants, namely, chlorinated dibenzodioxins and dibenzofurans, through lipid membranes has been simulated using classic molecular dynamics (CMD) combined with the umbrella sampling approach. The most toxic forms of chlorinated dibenzodioxin and dibenzofuran, 2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD) and 2,3,7,8-tetrachlorodibenzofuran (TCDF), and a [...] Read more.
The permeation of dioxin-like pollutants, namely, chlorinated dibenzodioxins and dibenzofurans, through lipid membranes has been simulated using classic molecular dynamics (CMD) combined with the umbrella sampling approach. The most toxic forms of chlorinated dibenzodioxin and dibenzofuran, 2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD) and 2,3,7,8-tetrachlorodibenzofuran (TCDF), and a dioleyl-phosphatidylcholine (DOPC) lipid membrane of 50 Å wide have been chosen for our study. The free energy profile shows the penetration process is largely favoured thermodynamically (ΔG ≈ −12 kcal/mol), with a progressively decrease of the free energy until reaching the energy minima at distances of 8 Å and 9.5 Å from the centre of the membrane for, respectively, TCDD and TCDF. At the centre of the membrane, both molecules display subtle local maxima with free energy differences of 0.5 and 1 kcal/mol with respect to the energy minima for TCDD and TCDF, respectively. Furthermore, the intermolecular interactions between the molecules and the lipid membrane have been characterized at the minima and the local maxima using hybrid quantum mechanics/molecular mechanics energy decomposition analysis (QM/MM-EDA). Total interaction energies of −17.5 and −16.5 kcal/mol have been found at the energy minima for TCDD and TCDF, respectively. In both cases, the dispersion forces govern the molecule-membrane interactions, no significant changes have been found at the local maxima, in agreement with the classical free energy profile. The small differences found in the results obtained for TCDD and TCDF point out that the adsorption and diffusion processes through the cell membrane are not related to the different toxicity shown by these pollutants. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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17 pages, 2185 KiB  
Article
Phase Imaging of Phosphatidylcholine Bilayer Membranes by Prodan Fluorescence
by Nobutake Tamai, Hitoshi Matsuki and Masaki Goto
Membranes 2022, 12(12), 1219; https://doi.org/10.3390/membranes12121219 - 02 Dec 2022
Viewed by 1219
Abstract
Prodan (6-propiponyl-2-(N,N-dimethylamino)naphthalene) is well known as a polarity-sensitive fluorescent probe and has a high capability of detecting structural changes occurring within phospholipid bilayer membranes. In this study, we carried out the fluorescence spectroscopic observation of bilayer phase behavior for [...] Read more.
Prodan (6-propiponyl-2-(N,N-dimethylamino)naphthalene) is well known as a polarity-sensitive fluorescent probe and has a high capability of detecting structural changes occurring within phospholipid bilayer membranes. In this study, we carried out the fluorescence spectroscopic observation of bilayer phase behavior for a series of symmetric saturated diacylphosphatidylcholines (CnPCs) with different acyl-chain length n (n = 12–15 and 19–22) using Prodan as a membrane probe to confirm the availability of Prodan along with the previous results for the CnPC bilayer membranes (n = 16–18). The results were discussed by constructing spectral three-dimensional (3D) imaging plots for visualizing the change in bilayer phase states with temperature or pressure to verify the functionality of this 3D imaging plot. It was found that the Prodan fluorescence technique is applicable to the detection of the changes in the bilayer phase states of all CnPCs with a few exceptions. One of the most crucial exceptions was that Prodan cannot be used for the detection of the bilayer-gel state of the C21PC bilayer membrane. It was also found that it is only to the CnPC bilayer membranes with n = 15–18 that the 3D imaging plot is adequately and accurately applicable as a useful graphical tool for visually detecting the bilayer phase states. This is a disadvantageous feature of this technique brought about by the high sensitivity of Prodan as a membrane probe. Further detailed studies on the molecular behavior of Prodan will enable us to find a more useful way of utilizing this membrane probe. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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19 pages, 7822 KiB  
Article
A Versatile Suspended Lipid Membrane System for Probing Membrane Remodeling and Disruption
by Achinta Sannigrahi, Vishwesh Haricharan Rai, Muhsin Vannan Chalil, Debayani Chakraborty, Subrat Kumar Meher and Rahul Roy
Membranes 2022, 12(12), 1190; https://doi.org/10.3390/membranes12121190 - 25 Nov 2022
Cited by 1 | Viewed by 1849
Abstract
Artificial membrane systems can serve as models to investigate molecular mechanisms of different cellular processes, including transport, pore formation, and viral fusion. However, the current, such as SUVs, GUVs, and the supported lipid bilayers suffer from issues, namely high curvature, heterogeneity, and surface [...] Read more.
Artificial membrane systems can serve as models to investigate molecular mechanisms of different cellular processes, including transport, pore formation, and viral fusion. However, the current, such as SUVs, GUVs, and the supported lipid bilayers suffer from issues, namely high curvature, heterogeneity, and surface artefacts, respectively. Freestanding membranes provide a facile solution to these issues, but current systems developed by various groups use silicon or aluminum oxide wafers for fabrication that involves access to a dedicated nanolithography facility and high cost while conferring poor membrane stability. Here, we report the development, characterization and applications of an easy-to-fabricate suspended lipid bilayer (SULB) membrane platform leveraging commercial track-etched porous filters (PCTE) with defined microwell size. Our SULB system offers a platform to study the lipid composition-dependent structural and functional properties of membranes with exceptional stability. With dye entrapped in PCTE microwells by SULB, we show that sphingomyelin significantly augments the activity of pore-forming toxin, Cytolysin A (ClyA) and the pore formation induces lipid exchange between the bilayer leaflets. Further, we demonstrate high efficiency and rapid kinetics of membrane fusion by dengue virus in our SULB platform. Our suspended bilayer membrane mimetic offers a novel platform to investigate a large class of biomembrane interactions and processes. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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18 pages, 2729 KiB  
Article
The Structural Changes in the Membranes of Staphylococcus aureus Caused by Hydrolysable Tannins Witness Their Antibacterial Activity
by Ewa Olchowik-Grabarek, Szymon Sękowski, Agnieszka Kwiatek, Jagoda Płaczkiewicz, Nodira Abdulladjanova, Vadim Shlyonsky, Izabela Swiecicka and Maria Zamaraeva
Membranes 2022, 12(11), 1124; https://doi.org/10.3390/membranes12111124 - 10 Nov 2022
Cited by 9 | Viewed by 1714
Abstract
Polyphenols, including tannins, are phytochemicals with pronounced antimicrobial properties. We studied the activity of two hydrolysable tannins, (i) gallotannin—1,2,3,4,5-penta-O-galloyl-β-D-glucose (PGG) and (ii) ellagitannin—1,2-di-O-galloyl-4,6-valoneoyl-β-D-glucose (dGVG), applied alone and in combination with antibiotics against Staphylococcus aureus strain 8324-4. We also evaluated the effect of these [...] Read more.
Polyphenols, including tannins, are phytochemicals with pronounced antimicrobial properties. We studied the activity of two hydrolysable tannins, (i) gallotannin—1,2,3,4,5-penta-O-galloyl-β-D-glucose (PGG) and (ii) ellagitannin—1,2-di-O-galloyl-4,6-valoneoyl-β-D-glucose (dGVG), applied alone and in combination with antibiotics against Staphylococcus aureus strain 8324-4. We also evaluated the effect of these tannins on bacterial membrane integrity and fluidity and studied their interaction with membrane proteins and lipids. A correlation between the antimicrobial activity of the tannins and their membranotropic action depending on the tannin molecular structure has been demonstrated. We found that the antibacterial activity of PGG was stronger than dGVG, which can be associated with its larger flexibility, dipole moment, and hydrophobicity. In addition, we also noted the membrane effects of the tannins observed as an increase in the size of released bacterial membrane vesicles. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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19 pages, 6665 KiB  
Article
Simulation Study of the Effect of Antimicrobial Peptide Associations on the Mechanism of Action with Bacterial and Eukaryotic Membranes
by Matko Maleš and Larisa Zoranić
Membranes 2022, 12(9), 891; https://doi.org/10.3390/membranes12090891 - 16 Sep 2022
Cited by 3 | Viewed by 2897
Abstract
Antimicrobial peptides (AMPs) can be directed to specific membranes based on differences in lipid composition. In this study, we performed atomistic and coarse-grained simulations of different numbers of the designed AMP adepantin-1 with a eukaryotic membrane, cytoplasmic Gram-positive and Gram-negative membranes, and an [...] Read more.
Antimicrobial peptides (AMPs) can be directed to specific membranes based on differences in lipid composition. In this study, we performed atomistic and coarse-grained simulations of different numbers of the designed AMP adepantin-1 with a eukaryotic membrane, cytoplasmic Gram-positive and Gram-negative membranes, and an outer Gram-negative membrane. At the core of adepantin-1’s behavior is its amphipathic α-helical structure, which was implemented in its design. The amphipathic structure promotes rapid self-association of peptide in water or upon binding to bacterial membranes. Aggregates initially make contact with the membrane via positively charged residues, but with insertion, the hydrophobic residues are exposed to the membrane’s hydrophobic core. This adaptation alters the aggregate’s stability, causing the peptides to diffuse in the polar region of the membrane, mostly remaining as a single peptide or pairing up to form an antiparallel dimer. Thus, the aggregate’s proposed role is to aid in positioning the peptide into a favorable conformation for insertion. Simulations revealed the molecular basics of adepantin-1 binding to various membranes, and highlighted peptide aggregation as an important factor. These findings contribute to the development of novel anti-infective agents to combat the rapidly growing problem of bacterial resistance to antibiotics. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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11 pages, 1556 KiB  
Article
PB1F2 from Influenza A Virus Regulates the Interaction between Cytochrome C and Cardiolipin
by Yujuan Wang and Junfeng Wang
Membranes 2022, 12(8), 795; https://doi.org/10.3390/membranes12080795 - 18 Aug 2022
Cited by 2 | Viewed by 1469
Abstract
PB1F2 is a membrane associated protein encoded by the influenza virus gene in the host. Similar to endogenous pro-apoptotic proteins, it acts on the mitochondria of the host immune cells, inducing apoptosis of the cells. The PB1F2 protein has been demonstrated to facilitate [...] Read more.
PB1F2 is a membrane associated protein encoded by the influenza virus gene in the host. Similar to endogenous pro-apoptotic proteins, it acts on the mitochondria of the host immune cells, inducing apoptosis of the cells. The PB1F2 protein has been demonstrated to facilitate the release of cytochrome c in addition to impairing the integrity of the inner mitochondrial membrane. This investigation focused on how the protein PB1F2 interacted with cardiolipin and cytochrome c. The regulation of PB1F2 on the binding of cytochrome c to cardiolipin in two kinds of in vitro membrane mimics was investigated by biophysical techniques. PB1F2 aids in the dissociation of cytochrome c-cardiolipin complexes in liposomes and nanodiscs. The results provide novel explanations and evidence for how PB1F2 functions as a viral virulence factor by inducing immune cell death. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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17 pages, 4762 KiB  
Article
Interaction of Oxicam Derivatives with the Artificial Models of Biological Membranes—Calorimetric and Fluorescence Spectroscopic Study
by Jadwiga Maniewska, Żaneta Czyżnikowska, Berenika M. Szczęśniak-Sięga and Krystyna Michalak
Membranes 2022, 12(8), 791; https://doi.org/10.3390/membranes12080791 - 17 Aug 2022
Cited by 1 | Viewed by 1799
Abstract
The modified 1,2-benzothiazine analogues designed as new drug candidates and discussed in this paper are oxicam derivatives. Oxicams are a class of non-steroidal anti-inflammatory drugs (NSAIDs). Their biological target is cyclooxygenase (COX), a membrane protein associated with the phospholipid bilayer. In recent decades, [...] Read more.
The modified 1,2-benzothiazine analogues designed as new drug candidates and discussed in this paper are oxicam derivatives. Oxicams are a class of non-steroidal anti-inflammatory drugs (NSAIDs). Their biological target is cyclooxygenase (COX), a membrane protein associated with the phospholipid bilayer. In recent decades, it has been proven that the biological effect of NSAIDs may be closely related to their interaction at the level of the biological membrane. These processes are often complicated and the biological membranes themselves are very complex. Therefore, to study these mechanisms, simplified models of biological membranes are used. To characterize the interaction of six oxicam derivatives with DPPC, DMPC and EYPC, artificial models of biological membranes (multi-bilayers or liposomes), differential scanning calorimetry (DSC) and fluorescence spectroscopy techniques were applied. In spectroscopic measurements, two fluorescent probes (Laurdan and Prodan) localized in different membrane segments were used. All tested oxicam derivatives interacted with the lipid bilayers and may penetrate the artificial models of biological membranes. They intercalated into the lipid bilayers and were located in the vicinity of the polar/apolar membrane interface. Moreover, a good drug candidate should not only have high efficiency against a molecular target but also exhibit strictly defined ADMET parameters, therefore these activities of the studied compounds were also estimated. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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20 pages, 2513 KiB  
Article
Liposomes Bearing Non-Bilayer Phospholipid Arrangements Induce Specific IgG Anti-Lipid Antibodies by Activating NK1.1+, CD4+ T Cells in Mice
by Carla Landa-Saldívar, Albany Reséndiz-Mora, Sandra Sánchez-Barbosa, Anahi Sotelo-Rodríguez, Giovanna Barrera-Aveleida, Irene Nevárez-Lechuga, Iván Galarce-Sosa, Keiko Taniguchi-Ponciano, Oriana del Rocío Cruz-Guzmán, Isabel Wong-Baeza, Alejandro Escobar-Gutiérrez, Isabel Baeza and Carlos Wong-Baeza
Membranes 2022, 12(7), 643; https://doi.org/10.3390/membranes12070643 - 23 Jun 2022
Cited by 1 | Viewed by 1816
Abstract
Liposomes are artificial models of cellular membranes that are used as delivery systems for genes, drugs and protein antigens. We have previously used them to study the antigenic properties of their phospholipids. Here, we used them to induce the production of IgG anti-non-bilayer [...] Read more.
Liposomes are artificial models of cellular membranes that are used as delivery systems for genes, drugs and protein antigens. We have previously used them to study the antigenic properties of their phospholipids. Here, we used them to induce the production of IgG anti-non-bilayer phospholipid arrangements (NPAs) antibodies in mice; these antibodies cause cell lysis and trigger a lupus-like disease in mice. We studied the mechanisms that lead to the production of these antibodies, and provide evidence that NK1.1+, CD4+ T cells respond to NPA-bearing liposomes and deliver the help required for specific B cell activation and antibody class-switching to IgG. We found increased numbers of IL-4-producing NK1.1+, CD4+ T cells in the secondary lymphoid organs of mice administered with NPAs, and these cells also expressed CD40L, which is required for B cell activation. Additionally, we isolated and purified NK1.1+, CD4+ T cells from spleens and determined that they over-expressed 40 genes, which are key players in inflammatory processes and B cell stimulation and have TRAF6 and UNC39B1 as key nodes in their network. These results show that liposomes are membrane models that can be used to analyze the immunogenicity of lipids. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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22 pages, 26377 KiB  
Article
Multiscale Dynamics of Lipid Vesicles in Polymeric Microenvironment
by Selcan Karaz, Mertcan Han, Gizem Akay, Asim Onal, Sedat Nizamoglu, Seda Kizilel and Erkan Senses
Membranes 2022, 12(7), 640; https://doi.org/10.3390/membranes12070640 - 21 Jun 2022
Cited by 3 | Viewed by 3120
Abstract
Understanding dynamic and complex interaction of biological membranes with extracellular matrices plays a crucial role in controlling a variety of cell behavior and functions, from cell adhesion and growth to signaling and differentiation. Tremendous interest in tissue engineering has made it possible to [...] Read more.
Understanding dynamic and complex interaction of biological membranes with extracellular matrices plays a crucial role in controlling a variety of cell behavior and functions, from cell adhesion and growth to signaling and differentiation. Tremendous interest in tissue engineering has made it possible to design polymeric scaffolds mimicking the topology and mechanical properties of the native extracellular microenvironment; however, a fundamental question remains unanswered: that is, how the viscoelastic extracellular environment modifies the hierarchical dynamics of lipid membranes. In this work, we used aqueous solutions of poly(ethylene glycol) (PEG) with different molecular weights to mimic the viscous medium of cells and nearly monodisperse unilamellar DMPC/DMPG liposomes as a membrane model. Using small-angle X-ray scattering (SAXS), dynamic light scattering, temperature-modulated differential scanning calorimetry, bulk rheology, and fluorescence lifetime spectroscopy, we investigated the structural phase map and multiscale dynamics of the liposome–polymer mixtures. The results suggest an unprecedented dynamic coupling between polymer chains and phospholipid bilayers at different length/time scales. The microviscosity of the lipid bilayers is directly influenced by the relaxation of the whole chain, resulting in accelerated dynamics of lipids within the bilayers in the case of short chains compared to the polymer-free liposome case. At the macroscopic level, the gel-to-fluid transition of the bilayers results in a remarkable thermal-stiffening behavior of polymer–liposome solutions that can be modified by the concentration of the liposomes and the polymer chain length. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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15 pages, 7543 KiB  
Article
Investigating the Permeation Mechanism of Typical Phthalic Acid Esters (PAEs) and Membrane Response Using Molecular Dynamics Simulations
by Yiqiong Bao, Mengrong Li, Yanjie Xie and Jingjing Guo
Membranes 2022, 12(6), 596; https://doi.org/10.3390/membranes12060596 - 06 Jun 2022
Cited by 1 | Viewed by 2093
Abstract
Phthalic acid esters (PAEs) are typical environmental endocrine disrupters, interfering with the endocrine system of organisms at very low concentrations. The plasma membrane is the first barrier for organic pollutants to enter the organism, so membrane permeability is a key factor affecting their [...] Read more.
Phthalic acid esters (PAEs) are typical environmental endocrine disrupters, interfering with the endocrine system of organisms at very low concentrations. The plasma membrane is the first barrier for organic pollutants to enter the organism, so membrane permeability is a key factor affecting their biological toxicity. In this study, based on computational approaches, we investigated the permeation and intramembrane aggregation of typical PAEs (dimethyl phthalate, DMP; dibutyl phthalate, DBP; di-2-ethyl hexyl phthalate, DEHP), as well as their effects on membrane properties, and related molecular mechanisms were uncovered. Our results suggested that PAEs could enter the membrane spontaneously, preferring the headgroup-acyl chain interface of the bilayer, and the longer the side chain (DEHP > DBP > DMP), the deeper the insertion. Compared with the shortest DMP, DEHP apparently increased membrane thickness, order, and rigidity, which might be due to its stronger hydrophobicity. Potential of means force (PMF) analysis revealed the presence of an energy barrier located at the water-membrane interface, with a maximum value of 2.14 kcal mol−1 obtained in the DEHP-system. Therefore, the difficulty of membrane insertion is also positively correlated with the side-chain length or hydrophobicity of PAE molecules. These findings will inspire our understanding of structure-activity relationship between PAEs and their effects on membrane properties, and provide a scientific basis for the formulation of environmental pollution standards and the prevention and control of small molecule pollutants. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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11 pages, 4518 KiB  
Article
Optimization of Giant Unilamellar Vesicle Electroformation for Phosphatidylcholine/Sphingomyelin/Cholesterol Ternary Mixtures
by Zvonimir Boban, Ivan Mardešić, Witold Karol Subczynski, Dražan Jozić and Marija Raguz
Membranes 2022, 12(5), 525; https://doi.org/10.3390/membranes12050525 - 16 May 2022
Cited by 5 | Viewed by 2164
Abstract
Artificial vesicles are important tools in membrane research because they enable studying membrane properties in controlled conditions. Giant unilamellar vesicles (GUVs) are specially interesting due to their similarity in size to eukaryotic cells. We focus on optimization of GUV production from phosphatidylcholine/sphingomyelin/cholesterol mixtures [...] Read more.
Artificial vesicles are important tools in membrane research because they enable studying membrane properties in controlled conditions. Giant unilamellar vesicles (GUVs) are specially interesting due to their similarity in size to eukaryotic cells. We focus on optimization of GUV production from phosphatidylcholine/sphingomyelin/cholesterol mixtures using the electroformation method. This mixture has been extensively researched lately due to its relevance for the formation of lipid rafts. We measured the effect of voltage, frequency, lipid film thickness, and cholesterol (Chol) concentration on electroformation successfulness using spin-coating for reproducible lipid film deposition. Special attention is given to the effect of Chol concentrations above the phospholipid bilayer saturation threshold. Such high concentrations are of interest to groups studying the role of Chol in the fiber cell plasma membranes of the eye lens or development of atherosclerosis. Utilizing atomic force and fluorescence microscopy, we found the optimal lipid film thickness to be around 30 nm, and the best frequency–voltage combinations in the range of 2–6 V and 10–100 Hz. Increasing the Chol content, we observed a decrease in GUV yield and size. However, the effect was much less pronounced when the optimal lipid film thickness was used. The results underline the need for simultaneous optimization of both electrical parameters and thickness in order to produce high-quality GUVs for experimental research. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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20 pages, 2042 KiB  
Article
Alpha-Crystallin-Membrane Association Modulated by Phospholipid Acyl Chain Length and Degree of Unsaturation
by Geraline Trossi-Torres, Raju Timsina and Laxman Mainali
Membranes 2022, 12(5), 455; https://doi.org/10.3390/membranes12050455 - 23 Apr 2022
Cited by 6 | Viewed by 2195
Abstract
α-crystallin-membrane association increases with age and cataracts, with the primary association site of α-crystallin being phospholipids. However, it is unclear if phospholipids’ acyl chain length and degree of unsaturation influence α-crystallin association. We used the electron paramagnetic resonance approach to investigate the association [...] Read more.
α-crystallin-membrane association increases with age and cataracts, with the primary association site of α-crystallin being phospholipids. However, it is unclear if phospholipids’ acyl chain length and degree of unsaturation influence α-crystallin association. We used the electron paramagnetic resonance approach to investigate the association of α-crystallin with phosphatidylcholine (PC) membranes of different acyl chain lengths and degrees of unsaturation and with and without cholesterol (Chol). The association constant (Ka) of α-crystallin follows the trends, i.e., Ka (14:0–14:0 PC) > Ka (18:0–18:1 PC) > Ka (18:1–18:1 PC) ≈ Ka (16:0–20:4 PC) where the presence of Chol decreases Ka for all membranes. With an increase in α-crystallin concentration, the saturated and monounsaturated membranes rapidly become more immobilized near the headgroup regions than the polyunsaturated membranes. Our results directly correlate the mobility and order near the headgroup regions of the membrane with the Ka, with the less mobile and more ordered membrane having substantially higher Ka. Furthermore, our results show that the hydrophobicity near the headgroup regions of the membrane increases with the α-crystallin association, indicating that the α-crystallin-membrane association forms the hydrophobic barrier to the transport of polar and ionic molecules, supporting the barrier hypothesis in cataract development. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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Review

Jump to: Research

11 pages, 2041 KiB  
Review
A Review of Continuum Mechanics for Mechanical Deformation of Lipid Membranes
by Jichul Kim
Membranes 2023, 13(5), 493; https://doi.org/10.3390/membranes13050493 - 03 May 2023
Viewed by 1329
Abstract
Mechanical deformation of lipid membranes plays important roles in various cellular tasks. Curvature deformation and lateral stretching are two major energy contributions to the mechanical deformation of lipid membranes. In this paper, continuum theories for these two major membrane deformation events were reviewed. [...] Read more.
Mechanical deformation of lipid membranes plays important roles in various cellular tasks. Curvature deformation and lateral stretching are two major energy contributions to the mechanical deformation of lipid membranes. In this paper, continuum theories for these two major membrane deformation events were reviewed. Theories based on curvature elasticity and lateral surface tension were introduced. Numerical methods as well as biological applications of the theories were discussed. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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23 pages, 3758 KiB  
Review
Modulation of the Dipole Potential of Model Lipid Membranes with Phytochemicals: Molecular Mechanisms, Structure–Activity Relationships, and Implications in Reconstituted Ion Channels
by Svetlana S. Efimova and Olga S. Ostroumova
Membranes 2023, 13(4), 453; https://doi.org/10.3390/membranes13040453 - 21 Apr 2023
Cited by 2 | Viewed by 1543
Abstract
Phytochemicals, such as flavonoids, stilbenoids, alkaloids, terpenoids, and related compounds, have a wide range of useful pharmacological properties which cannot be ascribed to binding to a single peptide or protein target alone. Due to the relatively high lipophilicity of phytochemicals, the lipid membrane [...] Read more.
Phytochemicals, such as flavonoids, stilbenoids, alkaloids, terpenoids, and related compounds, have a wide range of useful pharmacological properties which cannot be ascribed to binding to a single peptide or protein target alone. Due to the relatively high lipophilicity of phytochemicals, the lipid membrane is thought to mediate their effects via changes in the properties of the lipid matrix, in particular, by modulating the transmembrane distribution of the electrical potential and, consequently, the formation and functioning of the ion channels reconstituted in the lipid bilayers. Therefore, biophysical studies on the interactions between plant metabolites and model lipid membranes are still of interest. This review represents an attempt to provide a critical analysis of a variety of studies on altering membranes and ion channels with phytochemicals via disturbing the potential drop at the membrane–aqueous solution interface. Critical structural motifs and functioning groups in the molecules of plant polyphenols (alkaloids and saponins are identified) and the possible mechanisms of dipole potential modulation with phytochemicals are discussed. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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21 pages, 3841 KiB  
Review
Membrane Models and Experiments Suitable for Studies of the Cholesterol Bilayer Domains
by Ivan Mardešić, Zvonimir Boban, Witold Karol Subczynski and Marija Raguz
Membranes 2023, 13(3), 320; https://doi.org/10.3390/membranes13030320 - 10 Mar 2023
Cited by 3 | Viewed by 2281
Abstract
Cholesterol (Chol) is an essential component of animal cell membranes and is most abundant in plasma membranes (PMs) where its concentration typically ranges from 10 to 30 mol%. However, in red blood cells and Schwann cells, PMs Chol content is as high as [...] Read more.
Cholesterol (Chol) is an essential component of animal cell membranes and is most abundant in plasma membranes (PMs) where its concentration typically ranges from 10 to 30 mol%. However, in red blood cells and Schwann cells, PMs Chol content is as high as 50 mol%, and in the PMs of the eye lens fiber cells, it can reach up to 66 mol%. Being amphiphilic, Chol molecules are easily incorporated into the lipid bilayer where they affect the membrane lateral organization and transmembrane physical properties. In the aqueous phase, Chol cannot form free bilayers by itself. However, pure Chol bilayer domains (CBDs) can form in lipid bilayer membranes with the Chol content exceeding 50 mol%. The range of Chol concentrations surpassing 50 mol% is less frequent in biological membranes and is consequently less investigated. Nevertheless, it is significant for the normal functioning of the eye lens and understanding how Chol plaques form in atherosclerosis. The most commonly used membrane models are unilamellar and multilamellar vesicles (MLVs) and supported lipid bilayers (SLBs). CBDs have been observed directly using confocal microscopy, X-ray reflectometry and saturation recovery electron paramagnetic resonance (SR EPR). Indirect evidence of CBDs has also been reported by using atomic force microscopy (AFM) and fluorescence recovery after photobleaching (FRAP) experiments. The overall goal of this review is to demonstrate the advantages and limitations of the various membrane models and experimental techniques suitable for the detection and investigation of the lateral organization, function and physical properties of CBDs. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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49 pages, 19580 KiB  
Review
Remodeling of Biomembranes and Vesicles by Adhesion of Condensate Droplets
by Reinhard Lipowsky
Membranes 2023, 13(2), 223; https://doi.org/10.3390/membranes13020223 - 10 Feb 2023
Cited by 3 | Viewed by 2105
Abstract
Condensate droplets are formed in aqueous solutions of macromolecules that undergo phase separation into two liquid phases. A well-studied example are solutions of the two polymers PEG and dextran which have been used for a long time in biochemical analysis and biotechnology. More [...] Read more.
Condensate droplets are formed in aqueous solutions of macromolecules that undergo phase separation into two liquid phases. A well-studied example are solutions of the two polymers PEG and dextran which have been used for a long time in biochemical analysis and biotechnology. More recently, phase separation has also been observed in living cells where it leads to membrane-less or droplet-like organelles. In the latter case, the condensate droplets are enriched in certain types of proteins. Generic features of condensate droplets can be studied in simple binary mixtures, using molecular dynamics simulations. In this review, I address the interactions of condensate droplets with biomimetic and biological membranes. When a condensate droplet adheres to such a membrane, the membrane forms a contact line with the droplet and acquires a very high curvature close to this line. The contact angles along the contact line can be observed via light microscopy, lead to a classification of the possible adhesion morphologies, and determine the affinity contrast between the two coexisting liquid phases and the membrane. The remodeling processes generated by condensate droplets include wetting transitions, formation of membrane nanotubes as well as complete engulfment and endocytosis of the droplets by the membranes. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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14 pages, 2351 KiB  
Review
Multilamellar Liposomes as a Model for Biological Membranes: Saturation Recovery EPR Spin-Labeling Studies
by Witold Karol Subczynski, Marija Raguz and Justyna Widomska
Membranes 2022, 12(7), 657; https://doi.org/10.3390/membranes12070657 - 26 Jun 2022
Cited by 2 | Viewed by 2624
Abstract
EPR spin labeling has been used extensively to study lipids in model membranes to understand their structures and dynamics in biological membranes. The lipid multilamellar liposomes, which are the most commonly used biological membrane model, were prepared using film deposition methods and investigated [...] Read more.
EPR spin labeling has been used extensively to study lipids in model membranes to understand their structures and dynamics in biological membranes. The lipid multilamellar liposomes, which are the most commonly used biological membrane model, were prepared using film deposition methods and investigated with the continuous wave EPR technique (T2-sensitive spin-labeling methods). These investigations provided knowledge about the orientation of lipids, their rotational and lateral diffusion, and their rate of flip-flop between bilayer leaflets, as well as profiles of membrane hydrophobicity, and are reviewed in many papers and book chapters. In the early 1980s, the saturation recovery EPR technique was introduced to membrane studies. Numerous T1-sensitive spin-label methods were developed to obtain detailed information about the three-dimensional dynamic membrane structure. T1-sensitive methods are advantageous over T2-sensitive methods because the T1 of spin labels (1–10 μs) is 10 to 1000 times longer than the T2, which allows for studies of membrane dynamics in a longer time–space scale. These investigations used multilamellar liposomes also prepared using the rapid solvent exchange method. Here, we review works in which saturation recovery EPR spin-labeling methods were applied to investigate the properties of multilamellar lipid liposomes, and we discuss their relationships to the properties of lipids in biological membranes. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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11 pages, 2214 KiB  
Review
Progress on Crowding Effect in Cell-like Structures
by Chao Li, Xiangxiang Zhang, Mingdong Dong and Xiaojun Han
Membranes 2022, 12(6), 593; https://doi.org/10.3390/membranes12060593 - 03 Jun 2022
Cited by 4 | Viewed by 2980
Abstract
Several biological macromolecules, such as proteins, nucleic acids, and polysaccharides, occupy about 30% of the space in cells, resulting in a crowded macromolecule environment. The crowding effect within cells exerts an impact on the functions of biological components, the assembly behavior of biomacromolecules, [...] Read more.
Several biological macromolecules, such as proteins, nucleic acids, and polysaccharides, occupy about 30% of the space in cells, resulting in a crowded macromolecule environment. The crowding effect within cells exerts an impact on the functions of biological components, the assembly behavior of biomacromolecules, and the thermodynamics and kinetics of metabolic reactions. Cell-like structures provide confined and independent compartments for studying the working mechanisms of cells, which can be used to study the physiological functions arising from the crowding effect of macromolecules in cells. This article mainly summarizes the progress of research on the macromolecular crowding effects in cell-like structures. It includes the effects of this crowding on actin assembly behavior, tubulin aggregation behavior, and gene expression. The challenges and future trends in this field are presented at the end of the paper. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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16 pages, 1385 KiB  
Review
Extracellular Vesicles as Novel Drug-Delivery Systems through Intracellular Communications
by Yasunari Matsuzaka and Ryu Yashiro
Membranes 2022, 12(6), 550; https://doi.org/10.3390/membranes12060550 - 25 May 2022
Cited by 10 | Viewed by 3285
Abstract
Since it has been reported that extracellular vesicles (EVs) carry cargo using cell-to-cell comminication according to various in vivo situations, they are exprected to be applied as new drug-delivery systems (DDSs). In addition, non-coding RNAs, such as microRNAs (miRNAs), have attracted much attention [...] Read more.
Since it has been reported that extracellular vesicles (EVs) carry cargo using cell-to-cell comminication according to various in vivo situations, they are exprected to be applied as new drug-delivery systems (DDSs). In addition, non-coding RNAs, such as microRNAs (miRNAs), have attracted much attention as potential biomarkers in the encapsulated extracellular-vesicle (EV) form. EVs are bilayer-based lipids with heterogeneous populations of varying sizes and compositions. The EV-mediated transport of contents, which includes proteins, lipids, and nucleic acids, has attracted attention as a DDS through intracellular communication. Many reports have been made on the development of methods for introducing molecules into EVs and efficient methods for introducing them into target vesicles. In this review, we outline the possible molecular mechanisms by which miRNAs in exosomes participate in the post-transcriptional regulation of signaling pathways via cell–cell communication as novel DDSs, especially small EVs. Full article
(This article belongs to the Special Issue Artificial Models of Biological Membranes)
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