Bilayer Phase Research Articles

Smart Photothermal-Triggered Bilayer Phase Transition in AuNPs–Liposomes to Release Drug

Novel thermosensitive liposomes with embedded Au nanoparticles (AuNPs) in the liposome bilayer were prepared by a combination method of film build and supercritical CO(2) incubation. These AuNPs-liposomes possess AuNPs that are embedded in the bilayer and a drug that is encapsulated in the central aqueous compartment. The AuNPs in the liposomes can strongly absorb light energy and efficiently convert the absorbed energy to heat. The localized heat induces a phase transition in the liposome bilayer and releases the drug. The drug release from the AuNPs-liposomes can be controlled by the irradiation time and AuNPs concentration in the AuNPs-liposomes at room temperature, where the AuNPs function as a nanoswitch for triggering drug release both spatially and temporally. The results suggest that drug release from the AuNPs-liposomes is due to a photothermic effect that induces phase transition of the liposomes rather than destruction of the liposome bilayer.

Bubble nucleation in lipid bilayers: A mechanism for low frequency ultrasound disruption

Recent experiments have shown that low frequency ultrasound (LFUS) induces leakage from lipid vesicles. However, the mechanism by which LFUS disrupts the lipid bilayer structure is not clear. In this paper we develop a theoretical model to test the possibility that gas molecule partitioning from the aqueous media into the lipid bilayer core can lead to the nucleation of microscale gas bubbles. If those can, indeed, form, then their presence in the lipid bilayer and interactions with an ultrasound field can cause bilayer disruption and leakage. The model derived here for the nucleation of stable bubbles accounts for the ‘surface tension’ that the lipid bilayer exerts on the bubble, a result of the associated disruption of the lipid packing. The model predicts that the probability of bubble nucleation is highly sensitive to the bilayer thickness, and largely insensitive to the bilayer phase. The probability of stable bubble formation is shown to correlate with experimentally measured sensitivity of lipid bilayers to LFUS, suggesting that membrane disruption may be due to embedded bubbles that nucleated in the bilayer.

Lipid Bilayer Properties Control Membrane Partitioning, Binding, and Transport of P-Glycoprotein Substrates

The ABC protein P-glycoprotein (Pgp or ABCB1) is a multidrug efflux pump capable of transporting many structurally diverse substrates from within the lipid bilayer. Previous studies have demonstrated the importance of the membrane in modulating Pgp function, but few have quantified these effects. We employed purified Pgp reconstituted into phospholipid bilayers with defined gel to liquid-crystalline melting transitions to investigate the effect of membrane environment on the transporter and three of its substrates. Equilibrium dialysis measurements indicated that Hoechst 33342, LDS-751, and MK-571 partitioned much more readily into liquid-crystalline phase bilayers than into gel phase bilayers. However, drug binding affinities revealed that Pgp bound the three substrates more tightly when the lipid bilayer was in the gel phase. The binding affinity of the transporter for substrates within the bilayer was low, in the millimolar range, suggesting that it interacts with them weakly. Thermodynamic analysis revealed that both drug-Pgp and drug-lipid interactions contribute to binding affinity. The kinetics of LDS-751 and Hoechst 33342 transport by reconstituted Pgp was monitored using a real-time fluorescence-based assay to obtain apparent turnover frequencies. Transport rates were found to be sensitive to both drug structure and lipid environment. Arrhenius and transition state analysis of transport rates suggested that the rate of drug transport depends on both the affinity of Pgp for substrate and protein conformational changes. Transport rates did not appear to be limited exclusively by the rate of ATP hydrolysis and may be partially controlled by the rate of drug dissociation.

Charged membranes under confinement induced by polymer-, salt-, or ionic liquid solutions

Osmotic pressure confines and decreases the lamellar distance between membranes in a stack and may also change the phase or structure of lipid bilayers. Using solution X-ray scattering, we determined the structure and interactions of saturated (DLPS) and unsaturated (DOPS) charged lipids under osmotic stress, generated by osmolyte solutions consisting of polyethylene glycol (PEG), NaCl, or the ionic liquid EMIES. The measured pressure–distance curves were fit to the theoretical free energy of charged liquid membranes that included numerical solutions of the Poisson–Boltzmann theory, modified to account for nonelectrostatic interactions between counterions and the surface and between lipid molecules on the surface. Charged membranes exhibit a non-ideal swelling behaviour that is consistent with partial melting of the lamellar phase into a coexisting, disordered phase. The disordered phase applies an osmotic stress to the lamellar phase and decreases the spacing between bilayers in the lamellar phase. We showed that in pure water, the pressure of the disordered phase increased with the lipid volume fraction or temperature. Addition of osmolytes reduced the lamellar spacing. The numerical solutions that fit the data showed that at the critical osmolyte concentration, a small, sharp drop in the water spacing between bilayers is expected owing to massive adsorption of the counterions onto the membrane. The adsorption increases with the osmolyte concentration, and is accompanied by a lateral phase separation into domains of neutral (counterion adsorbing) and charged (non-adsorbing) lipid molecules. In the case of the ionic liquid, this transition was followed by a liquid-to-crystal phase transition of the bilayers. With NaCl the transition to the crystal phase required a significantly higher osmolyte concentration. In the crystal phase that was induced by the ionic liquid, the lipid molecules were more tilted than in the crystal phase formed by NaCl. A further increase of the ionic liquid concentration melted the lipid crystal phase into the gel phase.

Interactions of a Monofluorinated Phospholipid with Saturated Phosphatidylcholines of Different Chain Lengths

This study uses differential scanning calorimetry (DSC) and fluorescence spectroscopy to study the thermodynamic and kinetic effects of the monofluorinated phospholipid 1-palmitoyl-2-[16-fluoropalmitoyl]-phosphatidylcholine (F-DPPC) on bilayers composed of the fully saturated phosphatidylcholines 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). In both bilayer systems, DSC thermograms indicate a disappearance of pretransition peaks (Tp) along with a rise in main transition (Tm) hysteresis at elevated F-DPPC mol%. Fluorescence intensity measurements reveal an inverse relationship between F-DPPC mol% and the emission intensity of the environment-sensitive probe 1,6-diphenyl-1,3,5-hexatriene (DPH) below the main transitions of the respective lipids. These trends suggest a growth in interdigitated domains with the incorporation of additional F-DPPC into the bilayer. Significant drops in intensity values were observed at lower F-DPPC mole percentages in the DSPC system than the DMPC system, indicating that the latter lipid has a higher threshold for F-DPPC-induced interdigitation. Our results support that F-DPPC encourages the interdigitated phase (LβI) in saturated bilayers and highlight the stabilizing effect that long acyl chains have on this phase.

Suppression of Cooperative Motions in Phospholipid Membranes by Osmotic Stress: Deuterium NMR Relaxation Study

Understanding membrane dynamics is crucial to explaining the function of membrane proteins. Phospholipids are commonly employed as model systems to investigate biological membranes. The complex dynamic organization of phospholipid membranes spans several frequency decades, starting from sub-picosecond local motions to millisecond collective dynamics [1]. Such motional frequencies can be accessed using various NMR relaxation methods. To address membrane dynamics mediated by osmotic stress, we measured 2H longitudinal (R1Z) and transverse quadrupolar echo (R2QE) relaxation rates for the liquid-crystalline phase of DMPC-d54 membrane bilayers. Osmotic stress was applied by both dehydration and osmolyte concentration [2]. The R1Z values of individual acyl segments were independent of osmotic stress while the segmental order parameters (SCD) and R1Z profiles followed a theoretical square-law functional dependence [3]. The R2QE rates were found to be sensitive to osmotic pressure as well as the acyl position, thus yielding two important observations: enhanced transverse relaxation rates with increased amount of water per lipid, and limiting lower R2QE values as we dehydrate the membrane. The R2QE rates of the acyl segments and respective SCD values tend to follow a square-law behavior [3] with increasing lipid dehydration. At higher hydration the square-law behavior is limited to those acyl segments deeper in the hydrophobic region, with a break as the head group is approached. These results clearly indicate that water enhances slow cooperative motions whereas they are suppressed by dehydration. Additional complementary Carr-Purcell-Meiboom-Gill (CPMG) dispersion measurements map the frequency dependence of relaxation rates. Such studies in presence of membrane proteins give insight into optimized lipid hydration for their biological functions.[1] A. Leftin et al. (2011) BBA 1808, 818-839.[2] K.J. Mallikarjunaiah et al. (2011) BJ100, 98-107.[3] M.F. Brown (1982) JCP77, 1576-1599.

Long-Range Smectic Coupling of Phase Separated Domains in Ternary Mixture Lipid Multilayers

Lipid multilayers serve as suitable and convenient bio-mimetic systems and are broadly used for studies of lipid membrane structure and function. It is known that many mixed lipid systems undergo phase separation as a function of temperature. Here we report that, in multilayers, the lateral phase separation in the bilayers is accompanied by long-range columnar order of the two phases along the normal to the bilayers arising from the coupling of two-dimensional intra-layer phase separation and inter-layer smectic ordering. Quantitative analysis of real-time dynamical experiments of confocal florescence microscopy reveal an interplay between intra-layer domain growth and inter-layer coupling, while X-ray reflectivity studies establish that the phase-separated domains are correlated normal to the lamellae over hundreds of bilayers. Through reconstruction of relative electron density profiles, XRR data also offer insight into differences in the domain structure on nm length scales. The microscopic understanding of two coexisting and domain-aligned multilamellar phases advanced by our experiments shed new light on the role of water in organizing membrane phases in stacked bilayers - a phenomenon of possible relevance to the mechanism of inter-layer lipid-lipid interactions in biological membranes.View Large Image | View Hi-Res Image | Download PowerPoint Slide

A New Biomimetic Phase of Surfactant Bilayers Maintains Membrane Protein Activity

For several years lipidic cubic (Q) mesophases have been used to crystallize membrane proteins. Because they have the rheology of a thick paste, working with Q-phases remain a challenge. We will present a new fluid L3 phase in which transmembrane proteins such as Bacteriodopsin, SERCA1a, and Cytochrome oxidase maintain their activity. Macroscopically a L3 phase can be viewed as a sponge made of a surfactant whereas the holes in the sponge are filled with solvent. Topologically it consists of a single bilayer surrounded on either side by a solvent forming a continuous network of channels. It is comparable to a molten cubic phase, but it possesses water-like viscosity. Locally, it is similar to a lamellar phase but it is isotropic and optically transparent and thus suitable for spectroscopic studies. The L3 phases presented here were characterized by polarized light microscopy, diffusion of a fluorescent probe by fluorescence recovery after pattern photobleaching (FRAPP) and freeze fracture electron microscopy (FFEM).Tuning the distance between adjacent bilayers from 3 to 40 nm is an asset for the study of interactions between proteins. This is obtained by varying the water content of the phase. Characteristic distances (db) of the phase were obtained from small angle scattering spectra (SAXS/SANS) as well as from FFEM, which yielded similar db values: the L3 phase preserves its structure when a transmembrane protein is incorporated into the bilayers, when the non-ionic co-surfactant is replaced by another one and when the temperature varies from 6°C to 30°C. These findings illustrate that a biomimetic surfactant sponge phase can be obtained in the presence of detergents widely used to solubilize membrane proteins and thus make it a versatile medium for membrane protein studies.

Polyoxometalate macroion induced phase and morphology instability of lipid membrane

The interaction of multivalent macroions with cell membrane can have a profound and significant impact on the functionality and viability of the cell membrane, and this is also critically related to drug and gene delivery as well as nanomaterial cytotoxicity. Using AFM, calorimetry, and light scattering techniques, we have investigated the effect of an anionic polyoxometalate (POM) nanocluster as a model macroion on the phase and structural stability of a lipid bilayer. A POM is distinct from commonly used nanoparticles, in this case comprising a stoichiometric and ordered crystalline nanocluster of typically <5 nm in dimension with uniformly distributed high surface charge density. We have found that the anionic POM nanocluster can strongly adsorb onto a zwitterionic lipid bilayer, which is usually considered as neutral and uncharged, due to the strong electrostatic attraction in a similar fashion to the interaction of a POM with a cationic lipid bilayer. More interestingly, the adsorption of POM also results in the gelation of the lipid bilayer that is otherwise in the fluid phase in the absence of the POM macroion. By examining lipid bilayers with varied lipid headgroup chemistry and phase state, we have revealed that the energy released upon the POM adsorption on the lipid bilayer is contributed not only from the enthalpy associated with gelation, but also from the entropy associated with local surface reconstruction of the lipid bilayer. A POM-induced entropic penalty on the lipid bilayer is confirmed by both liposome shrinkage and bilayer morphological disruption, including the formation of pores, buds, and multilayer stacks on a POM-adsorbed lipid membrane. Hence, the accompanied phase and morphological instability induced by the POM is unique and surprising, in contrast to the fact that only one, but not both, of the phenomena has been reported previously with hydrophilic or hydrophobic nanoparticles. Our results offer an unprecedented new insight into nanomaterial design and selection for controlled molecular transport through cell membranes.

高圧蛍光法によるホスファチジルコリン二重膜のイメージング

High-pressure fluorescence study using a polarity-sensitive probe Prodan on phosphatidylcholine (PC) bilayers is reviewed. The author has constructed a three-dimensional image plot based on the second-derivative of the Prodan fluorescence spectra that change depending on the phase state of the PC bilayers, which enables us to examine the packing state of the bilayer. The effects of (1) acyl chain length, (2) vesicle size, and (3) chain asymmetry on the PC bilayers are discussed by using the technique of bilayer imaging. Further the formation of the lamellar crystal phase of the PC bilayer is also revealed by the technique.

Compositional sorting dynamics in coexisting lipid bilayer phases with variations in underlying e-beam formed curvature pattern.

Nanometer-scale curvature patterns of an underlying substrate are imposed on lipid multibilayers with each pattern imparting distinctly different sorting dynamics to a metastable pixelation pattern of coexisting liquid ordered (Lo)-liquid disordered (Ld) lipid phases. Therefore, this work provides pathways toward mechanical energy-based separations for analysis of biomembrane-associate species. The central design concept of the patterned sections of the silica substrate is a square lattice pattern of 100 nm projected radius poly(methyl methacrylate) (PMMA) hemispherical features formed by electron beam lithography which pixelates the coexisting phases in order to balance membrane bending and line energy. In one variation, we surround this pattern with three PMMA walls/fences 100 nm in height which substantially slows the loss of the high line energy pixelated Lo phase by altering the balance of two competing mechanism (Ostwald ripening vs. vesiculation). In another walled variation, we form a gradient of the spacing of the 100 nm features which forces partitioning of the Lo phase toward the end of the gradient with the most open (400 nm spacing) lattice pattern where a single vesicle could grow from the Lo phase. We show that two other variations distinctly impact the dynamics, demonstrating locally slowed loss of the high line energy pixelated Lo phase and spontaneous switching of the pixel location on the unit cell, respectively. Moreover, we show that the pixelation patterns can be regenerated and sharpened by a heating and cooling cycle. We argue that localized variations in the underlying curvature pattern have rather complex consequences because of the coupling and/or competition of dynamic processes to optimize mechanical energy such as lipid diffusion, vesiculation and growth, and phase/compositional partitioning.

Cholesteryl Phosphocholine forms Fluid Bilayer Membranes with Saturated or Monounsaturated Ceramides

Some ceramides have been shown to displace cholesterol from liquid ordered domains rich in sphingomyelin or saturated phosphatidylcholine in model membranes. The addition of ceramide will stabilize the formed ceramide/sphingomyelin domains and the subsequent partitioning of cholesterol to the disordered phase will also increase order and stabilization in this phase. The displacement of cholesterol may be due to more favorable interactions of ceramide with the ordered phase lipids, mainly sphingomyelin, compared to cholesterol. The ceramide could also interact less favorably with the disordered phase lipids compared to cholesterol, driving it into the ordered domains. It would also be of interest to better understand how cholesterol and ceramide can interact with each other in bilayer membranes. To study these questions, we have prepared a cholesterol analog with a phosphocholine head group on the 3-oxygen. We have studied the distribution and behavior of chol-PC and ceramides in bilayer systems on their own, and together with saturated and monounsaturated phospholipids. Chol-PC together with ceramide was able to form stable bilayer phases (extruded LUVs, electroformed GUVs). Phosphatidylcholine acyl chain order measurements showed that chol-PC was less efficient in inducing acyl chain order compared to cholesterol. Fluorescence quenching measurements in POPC/ceramide/sterol mixtures further showed a decrease in ordered domain stability of saturated ceramide in the presence of cholesterol or chol-PC. We have also examined the possibility to use chol-PC:ceramide mixtures to load ceramide into cultured cells. Proliferation experiments on HeLa and FRTL-5 cells indicates that chol-PC:ceramide bilayer mixtures are more efficient in inducing apoptosis than DMSO:ceramide mixtures. Our results suggest that chol-PC and ceramide interact with each other under specific conditions, and that the binary bilayers could constitute an interesting formulation for providing cells and tissues with solvent-free ceramides.

Metastability in pixelation patterns of coexisting fluid lipid bilayer phases imposed by e-beam patterned substrates.

We study the dynamic evolution of pixilation patterns of the liquid-ordered (Lo) phase in coexistence with the liquid-disordered phase in lipid multibilayers. The pixilation patterns were formed by imposing lattice patterns of localized high curvature on phase-separating multibilayers using curvature-patterned regions of an underlying support. The projected radius of underlying hemisphere-like features, that provided the local curvature, was varied from 60 nm to 100 nm and the square lattice spacing between the features was varied between 200 nm and 400 nm using standard electron (e) -beam lithography. Over time, the area fraction of the Lo phase on the patterned regions of the substrate decreased toward zero at room temperature. This apparent metastability of the pattern derives from the high line energy of a pixelation pattern where a Boltzmann distribution shows near zero equilibrium partitioning of the Lo phase in the patterned regions. Kinetic rate analysis identifies two pattern-dependent mechanisms that dominate the transition to zero Lo area fraction; diffusion limited dissolution of the Lo phase driven by an Ostwald ripening-type process or the cooperative formation of vesicles containing Lo phase lipids. Interestingly, we observed the spontaneous formation of tubules in the corners of the array due to the high local curvature applied to the membrane. Furthermore we show that it is possible to regenerate pixilation patterns on the curvature-patterned regions by cooling below room temperature. Regenerated area fractions are in agreement with a room-temperature composition of primarily Ld phase and the high degree of overlap with the original patterns is suggestive of fixed nucleation sites.

Surface Electrostatics of Lipid Bilayers by EPR of a pH-Sensitive Spin-Labeled Lipid

Many biophysical processes such as insertion of proteins into membranes and membrane fusion are governed by bilayer electrostatic potential. At the time of this writing, the arsenal of biophysical methods for such measurements is limited to a few techniques. Here we describe a, to our knowledge, new spin-probe electron paramagnetic resonance (EPR) approach for assessing the electrostatic surface potential of lipid bilayers that is based on a recently synthesized EPR probe (IMTSL-PTE) containing a reversibly ionizable nitroxide tag attached to the lipids’ polar headgroup. EPR spectra of the probe directly report on its ionization state and, therefore, on electrostatic potential through changes in nitroxide magnetic parameters and the degree of rotational averaging. Further, the lipid nature of the probe provides its full integration into lipid bilayers. Tethering the nitroxide moiety directly to the lipid polar headgroup defines the location of the measured potential with respect to the lipid bilayer interface. Electrostatic surface potentials measured by EPR of IMTSL-PTE show a remarkable (within ±2%) agreement with the Gouy-Chapman theory for anionic DMPG bilayers in fluid (48°C) phase at low electrolyte concentration (50 mM) and in gel (17°C) phase at 150-mM electrolyte concentration. This agreement begins to diminish for DMPG vesicles in gel phase (17°C) upon varying electrolyte concentration and fluid phase bilayers formed from DMPG/DMPC and POPG/POPC mixtures. Possible reasons for such deviations, as well as the proper choice of an electrostatically neutral reference interface, have been discussed. Described EPR method is expected to be fully applicable to more-complex models of cellular membranes.

Mechansim of the Early Stages of the Lamellar/Bicontinuous Cubic Phase Transition

The transition between lamellar and bicontinuous inverted cubic (QII) phases is mediated by catenoidal bilayer channels, which are also the structures that are produced by membrane fusion. The QII phase forms by production of these channels in an array of initially flat bilayers. As the number of channels increase with increasing temperature, they initially form a disordered, metastable array in the lamellar phase, which has been referred to as the “isotropic phase.” The isotropic phase accomplishes the topological change between the lamellar and QII phases. The disordered lattice subsequently transforms into the QII phase by local bending of the bilayers. There are discordant observations concerning the rate of formation and temperature interval of existence for the “isotopic phase.” Here, the expected dimensions of channels are predicted as a function of temperature, as well as the extent of “isotropic phase” formation as a function of temperature and sample water content. The predictions are made using the fourth order curvature energy model previously used to rationalize the stability of the QII phase in phospholipids (Langmuir, 2010, 26:8673). The extent of channel and “isotropic phase” formation is sensitive to the interaction energy of the flat bilayers in the lamellar phase, the lateral dimensions of the lamellar phase bilayers and the sample water volume fraction, as well as the temperature and curvature elastic parameters of the lipid. The theory, as well as the hysteretic nature of the transition process, accounts for the apparent conflict between early observations, made mostly by phosphorus NMR.

Coarse-grained simulation of transmembrane peptides in the gel phase

We use dissipative particle dynamics simulations, combined with parallel tempering and umbrella sampling, to investigate the potential of mean force between model transmembrane peptides in the various phases of a lipid bilayer, including the low-temperature gel phase. The observed oscillations in the effective interaction between peptides are consistent with the different structures of the surrounding lipid phases.

Ethanol effects on the gelation behavior of α-tocopherol acetate-encapsulated ethosomes with water-soluble polymers

This work aims at understanding the ethanol effects on the gelation behavior of ethosomes with the consideration of encapsulating a hydrophobic material. Gelation of the empty ethosomes by positively charged water-soluble polymers with and without hydrophobic modification, respectively, was systematically studied first for the effects of solution dielectric constant and gelator concentration on the phase map and rheological property of the mixtures. A comparison of the gelation behavior of empty and α-tocopherol acetate (α-TA)-encapsulated ethosomes sheds light on the possible influence of encapsulated hydrophobic material itself on the interaction between ethosomal lipid bilayers and gelator molecules. The experimental results revealed that ethosomes with an optimized amount of ethanol could result in a reasonable lifetime and encapsulation efficiency of more than 90 %. This is due to the effects of the solution dielectric constant on the formability of liposome and the partition of the hydrophobic material (α-TA) between ethosomal lipid bilayer and bulk phase. Moreover, the phase map and rheological property of the ethosome/polymer mixtures were found to be affected by the configuration of the polymer chain in aqueous ethanol solution. That is, the driving interactions between ethosomal lipid bilayers and gelator molecules were dominated by the hydrophobic material more than the electrostatic association. Finally, inclusion of a hydrophobic material, such as α-TA, in the ethosomes had less influence on the gelation behavior of the ethosomes with water-soluble polymers.

Dielectric relaxation change of water upon phase transition of a lipid bilayer probed by terahertz time domain spectroscopy

We investigate the influence of the 1, 2-ditetradecanoyl-sn-glycero-3-phosphocholine lipid bilayer phases on the water reorientation dynamics with terahertz time domain spectroscopy. The phase of the lipids was controlled by the temperature in the range of 14-35 °C. During the gel-to-fluid phase transition, the hydration water ratio drastically changed from 0.3 to 0.6. The absorption coefficient of the hydration water increased with the temperature in the gel phase and then decreased in the fluid phase. The dielectric relaxation time of the lipid solution decreased initially but then increased after the phase transition. This indicates that the hydration water reorientation dynamics are restricted by lipids and that this phenomenon is pronounced in a biologically relevant fluid phase.

Norovirus GII.4 virus-like particles recognize galactosylceramides in domains of planar supported lipid bilayers.

A sticky situation: Domain-dependent recognition of the glycosphingolipid galactosylceramide by norovirus-like particles (see picture; red/yellow) is shown using supported lipid bilayers (purple) as model membranes. Optimal ligand presentation is found to promote strong binding to GalCer. This presentation can be found at the edges of the glycosphingolipid-enriched domains (green) and binding is repressed in the absence of these domains.

Long-range interlayer alignment of intralayer domains in stacked lipid bilayers

Liquid-crystalline phases of stacked lipid bilayers represent a pervasive motif in biomolecular assemblies. Here we report that, in addition to the usual smectic order, multicomponent multilayer membranes can exhibit columnar order arising from the coupling of two-dimensional intralayer phase separation and interlayer smectic ordering. This coupling propagates across hundreds of membrane lamellae, producing long-range alignment of phase-separated domains. Quantitative analysis of real-time dynamical experiments reveals that there is an interplay between intralayer domain growth and interlayer coupling, suggesting the existence of cooperative multilayer epitaxy. We postulate that such long-range epitaxy is solvent-assisted, and that it originates from the surface tension associated with differences in the network of hydrogen-bonded water molecules at the hydrated interfaces between the domains and the surrounding phase. Our findings might inspire the development of self-assembly-based strategies for the long-range alignment of functional lipid domains.