Model membrane platforms for biomedicine: case study on antiviral drug development

Unraveling How Antimicrobial Lipid Mixtures Disrupt Virus-Mimicking Lipid Vesicles: A QCM-D Study

Single-chain lipid amphiphiles such as fatty acids and monoglycerides are promising antimicrobial alternatives to replace industrial surfactants for membrane-enveloped pathogen inhibition. Biomimetic lipid membrane platforms in combination with label-free biosensing techniques offer a promising route to compare the membrane-disruptive properties of different fatty acids and monoglycerides individually and within mixtures. Until recently, most related studies have utilized planar model membrane platforms, and there is an outstanding need to investigate how antimicrobial lipid mixtures disrupt curved model membrane platforms such as intact vesicle adlayers that are within the size range of membrane-enveloped virus particles. This need is especially evident because certain surfactants that completely disrupt planar/low-curvature membranes are appreciably less active against high-curvature membranes. Herein, we conducted quartz crystal microbalance-dissipation (QCM-D) measurements to investigate the membrane-disruptive properties of glycerol monolaurate (GML) monoglyceride and lauric acid (LA) fatty acid mixtures to rupture high-curvature, ~75 nm diameter lipid vesicle adlayers. We identified that the vesicle rupture activity of GML/LA mixtures mainly occurred above the respective critical micelle concentration (CMC) of each mixture, and that 25/75 mol% GML/LA micelles exhibited the greatest degree of vesicle rupture activity with ~100% efficiency that exceeded the rupture activity of other tested mixtures, individual compounds, and past reported values with industrial surfactants. Importantly, 25/75 GML/LA micelles outperformed 50/50 GML/LA micelles, which were previously reported to have the greatest membrane-disruptive activity towards planar model membranes. We discuss the mechanistic principles behind how antimicrobial lipid engineering can influence membrane-disruptive activity in terms of optimizing the balance between competitive membrane remodeling processes and inducing anisotropic vs. isotropic spontaneous curvature in lipid membrane systems.

Probing the Ion Transport Properties of Ultrashort Carbon Nanotubes Integrated with Supported Lipid Bilayers via Electrochemical Analysis

Supported lipid bilayers (SLBs) are commonly used to investigate interactions between cell membranes and their environment. These model platforms can be formed on electrode surfaces and analyzed using electrochemical methods for bioapplications. Carbon nanotube porins (CNTPs) integrated with SLBs have emerged as promising artificial ion channel platforms. In this study, we present the integration and ion transport characterization of CNTPs in in vivo environments. We combine experimental and simulation data obtained from electrochemical analysis to analyze the membrane resistance of the equivalent circuits. Our results show that carrying CNTPs on a gold electrode results in high conductance for monovalent cations (K⁺ and Na⁺) and low conductance for divalent cations (Ca²⁺).

Lipid Membrane Interface Viewpoint: From Viral Entry to Antiviral and Vaccine Development

Membrane-enveloped viruses are responsible for most viral pandemics in history, and more effort is needed to advance broadly applicable countermeasures to mitigate the impact of future outbreaks. In this Perspective, we discuss how biosensing techniques associated with lipid model membrane platforms are contributing to improving our mechanistic knowledge of membrane fusion and destabilization that is closely linked to viral entry as well as vaccine and antiviral drug development. A key benefit of these platforms is the simplicity of interpreting the results which can be complemented by other techniques to decipher more complicated biological observations and evaluate the biophysical functionalities that can be correlated to biological activities. Then, we introduce exciting application examples of membrane-targeting antivirals that have been refined over time and will continue to improve based on biophysical insights. Two ways to abrogate the function of viral membranes are introduced here: (1) selective disruption of the viral membrane structure and (2) alteration of the membrane component. While both methods are suitable for broadly useful antivirals, the latter also has the potential to produce an inactivated vaccine. Collectively, we emphasize how biosensing tools based on membrane interfacial science can provide valuable information that could be translated into biomedicines and improve their selectivity and performance.

Biophysical Characterization of LTX-315 Anticancer Peptide Interactions with Model Membrane Platforms: Effect of Membrane Surface Charge

LTX-315 is a clinical-stage, anticancer peptide therapeutic that disrupts cancer cell membranes. Existing mechanistic knowledge about LTX-315 has been obtained from cell-based biological assays, and there is an outstanding need to directly characterize the corresponding membrane-peptide interactions from a biophysical perspective. Herein, we investigated the membrane-disruptive properties of the LTX-315 peptide using three cell-membrane-mimicking membrane platforms on solid supports, namely the supported lipid bilayer, intact vesicle adlayer, and tethered lipid bilayer, in combination with quartz crystal microbalance-dissipation (QCM-D) and electrochemical impedance spectroscopy (EIS) measurements. The results showed that the cationic LTX-315 peptide selectively disrupted negatively charged phospholipid membranes to a greater extent than zwitterionic or positively charged phospholipid membranes, whereby electrostatic interactions were the main factor to influence peptide attachment and membrane curvature was a secondary factor. Of note, the EIS measurements showed that the LTX-315 peptide extensively and irreversibly permeabilized negatively charged, tethered lipid bilayers that contained high phosphatidylserine lipid levels representative of the outer leaflet of cancer cell membranes, while circular dichroism (CD) spectroscopy experiments indicated that the LTX-315 peptide was structureless and the corresponding membrane-disruptive interactions did not involve peptide conformational changes. Dynamic light scattering (DLS) measurements further verified that the LTX-315 peptide selectively caused irreversible disruption of negatively charged lipid vesicles. Together, our findings demonstrate that the LTX-315 peptide preferentially disrupts negatively charged phospholipid membranes in an irreversible manner, which reinforces its potential as an emerging cancer immunotherapy and offers a biophysical framework to guide future peptide engineering efforts.

Nanoarchitectured air-stable supported lipid bilayer incorporating sucrose-bicelle complex system

Cell-membrane-mimicking supported lipid bilayers (SLBs) provide an ultrathin, self-assembled layer that forms on solid supports and can exhibit antifouling, signaling, and transport properties among various possible functions. While recent material innovations have increased the number of practically useful SLB fabrication methods, typical SLB platforms only work in aqueous environments and are prone to fluidity loss and lipid-bilayer collapse upon air exposure, which limits industrial applicability. To address this issue, herein, we developed sucrose-bicelle complex system to fabricate air-stable SLBs that were laterally mobile upon rehydration. SLBs were fabricated from bicelles in the presence of up to 40 wt% sucrose, which was verified by quartz crystal microbalance-dissipation (QCM-D) and fluorescence recovery after photobleaching (FRAP) experiments. The sucrose fraction in the system was an important factor; while 40 wt% sucrose induced lipid aggregation and defects on SLBs after the dehydration-rehydration process, 20 wt% sucrose yielded SLBs that exhibited fully recovered lateral mobility after these processes. Taken together, these findings demonstrate that sucrose-bicelle complex system can facilitate one-step fabrication of air-stable SLBs that can be useful for a wide range of biointerfacial science applications.

Role of Membrane Stretch in Adsorption of Antiviral Peptides onto Lipid Membranes and Membrane Pore Formation

Many medically important viruses are enveloped viruses, which are surrounded by a structurally conserved, host-derived lipid membrane coating. Agents that target and disrupt this membrane coating could potentially function as broad-spectrum antiviral drugs. The amphipathic α-helical (AH) peptide derived from the N-terminus of the hepatitis C virus NS5A protein is one such candidate and has been demonstrated to be able to selectively rupture lipid vesicles in the size range of viruses (<160 nm diameter). However, the mechanism underlying this membrane curvature selectivity remains elusive. In this study, we have performed molecular dynamics simulations to study the binding of the AH peptide to model membranes that are stretched to resemble the looser lipid headgroup packing present on highly curved outer membranes of nanoscale vesicles. We found that the AH peptide binds more favorably to membranes that are stretched. In addition, a tetrameric placement of peptides across the membrane induced stable pore formation in the stretched membrane. Thus, our results suggest that the AH peptide senses the high curvature of nanoscale vesicles via the enhanced exposure of lipid packing defects induced by membrane area strain.

BALM: Watching the Formation of Tethered Bilayer Lipid Membranes with Submicron Lateral Resolution

Tethered bilayer lipid membranes (tBLMs) are artificial membranes largely used for the in situ study of biological membranes and membrane-associated proteins. To date, the formation of these membranes was essentially monitored by surface averaging techniques like surface plasmon resonance (SPR) and quartz crystal microbalance with dissipation monitoring (QCM-D), which cannot provide both local and real-time information in a single approach. Here, we report an original application of backside absorbing layer microscopy (BALM), a novel white-light wide-field optical microscopy, to study tBLMs. Thanks to the combination of sensitivity and resolution, BALM not only allowed the real-time quantitative monitoring of tBLM formation but also enabled the high-resolution visualization of local fluxes and matter exchanges taking place at each step of the process. Quantitative BALM measurements of the final layer thickness, reproduced in parallel with SPR, were consistent with the achievement of a continuous lipid bilayer. This finding was confirmed by BALM imaging, which additionally revealed the heterogeneity of the bilayer during its formation. While established real-time techniques, like SPR or QCM-D, view the surface as homogeneous, BALM showed the presence of surface patterns appearing in the first step of the tBLM formation process and governing subsequent matter adsorption or desorption steps. Finally, matter fluxes persisting even after rinsing at the end of the tBLM formation demonstrated the lasting presence of dispersed vesicular pockets with laterally fluctuating positions over the final single and continuous lipid bilayer. These new mechanistic insights into the tBLM formation process demonstrate the great potential of BALM in the study of complex biological systems.

Mechanistic Aspects of the Evolution of 3D Cholesterol Crystallites in a Supported Lipid Membrane via a Quartz Crystal Microbalance with Dissipation Monitoring

The irreversible formation of cholesterol monohydrate crystals within biological membranes is the leading cause of various diseases, including atherosclerosis. Understanding the process of cholesterol crystallization is fundamentally important and could also lead to the development of improved therapeutic strategies. This has driven several studies investigating the effect of the environmental parameters on the induction of cholesterol crystallite growth and the structure of the cholesterol crystallites, while the kinetics and mechanistic aspects of the crystallite formation process within lipid membranes remain poorly understood. Herein, we fabricated cholesterol crystallites within a supported lipid bilayer (SLB) by adsorbing a cholesterol-rich bicellar mixture onto a glass and silica surface and investigated the real-time kinetics of cholesterol crystallite nucleation and growth using epifluorescence microscopy and quartz crystal microbalance with dissipation (QCM-D) monitoring. Microscopic imaging showed the evolution of the morphology of cholesterol crystallites from nanorod- and plate-shaped habits during the initial stage to mostly large, micron-sized three-dimensional (3D) plate-shaped crystallites in the end, which was likened to Ostwald ripening. QCM-D kinetics revealed unique signal responses during the later stage of the growth process, characterized by simultaneous positive frequency shifts, nonmonotonous energy dissipation shifts, and significant overtone dependence. Based on the optically observed changes in crystallite morphology, we discussed the physical background of these unique QCM-D signal responses and the mechanistic aspects of Ostwald ripening in this system. Together, our findings revealed mechanistic details of the cholesterol crystallite growth kinetics, which may be useful in biointerfacial sensing and bioanalytical applications.

Biologically interfaced nanoplasmonic sensors

Understanding biointerfacial processes is crucial in various fields across fundamental and applied biology, but performing quantitative studies via conventional characterization techniques remains challenging due to instrumentation as well as analytical complexities and limitations. In order to accelerate translational research and address current challenges in healthcare and medicine, there is an outstanding need to develop surface-sensitive technologies with advanced measurement capabilities. Along this line, nanoplasmonic sensing has emerged as a powerful tool to quantitatively study biointerfacial processes owing to its high spatial resolution at the nanoscale. Consequently, the development of robust biological interfacing strategies becomes imperative to maximize its characterization potential. This review will highlight and discuss the critical role of biological interfacing within the context of constructing nanoplasmonic sensing platforms for biointerfacial science applications. Apart from paving the way for the development of highly surface-sensitive characterization tools that will spur fundamental biological interaction studies and improve the overall understanding of biological processes, the basic principles behind biointerfacing strategies presented in this review are also applicable to other fields that involve an interface between an inorganic material and a biological system.

Supported Lipid Bilayer Formation: Beyond Vesicle Fusion

Supported lipid bilayers (SLBs) are cell-membrane-mimicking platforms that can be formed on solid surfaces and integrated with a wide range of surface-sensitive measurement techniques. SLBs are useful for unravelling details of fundamental membrane biology and biophysics as well as for various medical, biotechnology, and environmental science applications. Thus, there is high interest in developing simple and robust methods to fabricate SLBs. Currently, vesicle fusion is a popular method to form SLBs and involves the adsorption and spontaneous rupture of lipid vesicles on a solid surface. However, successful vesicle fusion depends on high-quality vesicle preparation, and it typically works with a narrow range of material supports and lipid compositions. In this Feature Article, we summarize current progress in developing two new SLB fabrication techniques termed the solvent-assisted lipid bilayer (SALB) and bicelle methods, which have compelling advantages such as simple sample preparation and compatibility with a wide range of material supports and lipid compositions. The molecular self-assembly principles underpinning the two strategies and important experimental parameters are critically discussed, and recent application examples are presented. Looking forward, we envision that these emerging SLB fabrication strategies can be widely adopted by specialists and nonspecialists alike, paving the way to enriching our understanding of lipid membrane properties and realizing new application possibilities.

Comparing the Membrane-Interaction Profiles of Two Antiviral Peptides: Insights into Structure-Function Relationship

In recent years, certain amphipathic, α-helical peptides have been discovered that inhibit medically important enveloped viruses by disrupting the lipid membrane surrounding individual virus particles. Interestingly, only a small subset of amphipathic, α-helical peptides demonstrate inhibitory activity, and there is broad interest in understanding how the structures of these peptides contribute to functional activity against lipid membranes. To address this question, herein, we employed multiple surface-sensitive measurement techniques along with computational simulations in order to investigate how AH and C5A peptides, two of the most biologically active peptides in this class, interact with model lipid membranes while gaining insight into membrane-induced peptide conformational changes. Circular dichroism spectroscopy experiments revealed that both AH and C5A peptides undergo pronounced coil-to-helix transitions in the presence of lipid membrane environments, and the C5A conformational change was the largest. Time-lapsed fluorescence microscopy measurements were conducted to monitor the interaction of peptides with arrays of tethered, individual lipid vesicles and showed that C5A potently lyses lipid vesicles indiscriminate of vesicle size at peptide concentrations as low as 10 nM whereas AH peptide preferentially lyses lipid vesicles with high membrane curvature and is less potent than C5A. These findings were complemented by electrochemical impedance spectroscopy measurements on a tethered lipid bilayer membrane platform, which indicated that C5A solubilizes lipid membranes in a manner that is distinct from how AH disrupts lipid membranes via pore formation. Computational simulations supported that the distinct membrane-interaction profiles arise from different helical folding patterns, whereby AH monomers predominantly exist as two shorter helices with a hinge in-between and C5A monomers form a single helix. Taken together, our findings demonstrate that membrane-active antiviral peptides can exhibit distinct membrane-interaction profiles that confer different degrees of targeting selectivity, and the corresponding structural insights will be useful for peptide engineering applications.

Amyloid-β Peptide Triggers Membrane Remodeling in Supported Lipid Bilayers Depending on Their Hydrophobic Thickness

Amyloid-β (Aβ) peptide has been implicated in Alzheimer's disease, which is a leading cause of death worldwide. The interaction of Aβ peptides with the lipid bilayers of neuronal cells is a critical step in disease pathogenesis. Recent evidence indicates that lipid bilayer thickness influences Aβ membrane-associated aggregation, while understanding how Aβ interacts with lipid bilayers remains elusive. To address this question, we employed supported lipid bilayer (SLB) platforms composed of different-length phosphatidylcholine (PC) lipids (C12:0 DLPC, C18:1 DOPC, C18:1-C16:0 POPC), and characterized the resulting interactions with soluble Aβ monomers. Quartz crystal microbalance-dissipation (QCM-D) experiments identified concentration-dependent Aβ peptide adsorption onto all tested SLBs, which was corroborated by fluorescence recovery after photobleaching (FRAP) experiments indicating that higher Aβ concentrations led to decreased membrane fluidity. These commonalities pointed to strong Aβ peptide-membrane interactions in all cases. Notably, time-lapsed fluorescence microscopy revealed major differences in Aβ-induced membrane morphological responses depending on SLB hydrophobic thickness. For thicker DOPC and POPC SLBs, membrane remodeling involved the formation of elongated tubule and globular structures as a passive means to regulate membrane stress depending on Aβ concentration. In marked contrast, thin DLPC SLBs were not able to accommodate extensive membrane remodeling. Taken together, our findings reveal that membrane thickness influences the membrane morphological response triggered upon Aβ adsorption.

Detection of Amphipathic Viral Peptide on Screen-Printed Electrodes by Liposome Rupture Impact Voltammetry

Detection of infectious viruses and disease biomarkers is of utmost importance in clinical screening for effective identification and treatment of diseases. We demonstrate here the use of liposome rupture impact voltammetry for the qualitative detection of model amphipathic viral peptide on a screen-printed electrode. This novel, proof-of-concept method was proposed for the quick and reliable detection of viruses by nonfaradaic liposome rupture impact voltammetry with the aid of 1,2-dioleoyl-sn-glycero-3-phosphocholine liposomes. This provides an avenue for the development of future on-site, point-of-care detection devices for medical and biological applications.

Plasmonic Nanohole Sensor for Capturing Single Virus-Like Particles toward Virucidal Drug Evaluation

A plasmonic nanohole sensor for virus-like particle capture and virucidal drug evaluation is reported. Using a materials-selective surface functionalization scheme, passive immobilization of virus-like particles only within the nanoholes is achieved. The findings demonstrate that a low surface coverage of particles only inside the functionalized nanoholes significantly improves nanoplasmonic sensing performance over conventional nanohole arrays.

Relationship between vesicle size and steric hindrance influences vesicle rupture on solid supports

Although it is thermodynamically favorable for adsorbed vesicles to rupture with increasing vesicle size, this study demonstrates that steric hindrance acts as a kinetic barrier to impede large vesicles from rupturing.

Correlation between Membrane Partitioning and Functional Activity in a Single Lipid Vesicle Assay Establishes Design Guidelines for Antiviral Peptides

The nanometer-scale discrimination of virus-rupturing peptides is tested using lipid membrane platforms. In combination with single-vesicle analysis of peptide-induced vesicle rupture, a correlation between membrane partitioning and biologically relevant activities is established. Taken together, the findings support that the degree of rupture activity should be balanced by membrane curvature-selectivity for optimal therapeutic properties of antiviral peptides.

Membrainy: a 'smart', unified membrane analysis tool

BACKGROUND

The study of biological membranes using Molecular Dynamics has become an increasingly popular means by which to investigate the interactions of proteins, peptides and potentials with lipid bilayers. These interactions often result in changes to the properties of the lipids which can modify the behaviour of the membrane. Membrainy is a unified membrane analysis tool that contains a broad spectrum of analytical techniques to enable: measurement of acyl chain order parameters; presentation of 2D surface and thickness maps; determination of lateral and axial headgroup orientations; measurement of bilayer and leaflet thickness; analysis of the annular shell surrounding membrane-embedded objects; quantification of gel percentage; time evolution of the transmembrane voltage; area per lipid calculations; and quantification of lipid mixing/demixing entropy.

RESULTS

Each analytical component within Membrainy has been tested on a variety of lipid bilayer systems and was found to be either comparable to or an improvement upon existing software. For the analytical techniques that have no direct comparable software, our results were confirmed with experimental data.

CONCLUSIONS

Membrainy is a user-friendly, intelligent membrane analysis tool that automatically interprets a variety of input formats and force fields, is compatible with both single and double bilayers, and capable of handling asymmetric bilayers and lipid flip-flopping. Membrainy has been designed for ease of use, requiring no installation or configuration and minimal user-input to operate.

Lamellar sheet exfoliation of single lipid vesicles by a membrane-active peptide

Using total internal fluorescence microscopy, highly parallel measurements of single lipid vesicles unexpectedly reveal that a small fraction of vesicles rupture in multiple discrete steps when destabilized by a membrane-active peptide which is in contrast to classical solubilization models.

Model cell membranes: Techniques to form complex biomimetic supported lipid bilayers via vesicle fusion

Vesicle fusion has long provided an easy and reliable method to form supported lipid bilayers (SLBs) from simple, zwitterionic vesicles on siliceous substrates. However, for complex compositions, such as vesicles with high cholesterol content and multiple lipid types, the energy barrier for the vesicle-to-bilayer transition is increased or the required vesicle-vesicle and vesicle-substrate interactions are insufficient for vesicle fusion. Thus, for vesicle compositions that more accurately mimic native membranes, vesicle fusion often fails to form SLBs. In this paper, we review three approaches to overcome these barriers to form complex, biomimetic SLBs via vesicle fusion: (i) optimization of experimental conditions (e.g., temperature, buffer ionic strength, osmotic stress, cation valency, and buffer pH), (ii) α-helical (AH) peptide-induced vesicle fusion, and (iii) bilayer edge-induced vesicle fusion. AH peptide-induced vesicle fusion can form complex SLBs on multiple substrate types without the use of additional equipment. Bilayer edge-induced vesicle fusion uses microfluidics to form SLBs from vesicles with complex composition, including vesicles derived from native cell membranes. Collectively, this review introduces vesicle fusion techniques that can be generalized for many biomimetic vesicle compositions and many substrate types, and thus will aid efforts to reliably create complex SLB platforms on a range of substrates.

Comparison of Extruded and Sonicated Vesicles for Planar Bilayer Self-Assembly

Lipid vesicles are an important class of biomaterials that have a wide range of applications, including drug delivery, cosmetic formulations and model membrane platforms on solid supports. Depending on the application, properties of a vesicle population such as size distribution, charge and permeability need to be optimized. Preparation methods such as mechanical extrusion and sonication play a key role in controlling these properties, and yet the effects of vesicle preparation method on vesicular properties and integrity (e.g., shape, size, distribution and tension) remain incompletely understood. In this study, we prepared vesicles composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid by either extrusion or sonication, and investigated the effects on vesicle size distribution over time as well as the concomitant effects on the self-assembly of solid-supported planar lipid bilayers. Dynamic light scattering (DLS), quartz crystal microbalance with dissipation (QCM-D) monitoring, fluorescence recovery after photobleaching (FRAP) and atomic force microscopy (AFM) experiments were performed to characterize vesicles in solution as well as their interactions with silicon oxide substrates. Collectively, the data support that sonicated vesicles offer more robust control over the self-assembly of homogenous planar lipid bilayers, whereas extruded vesicles are vulnerable to aging and must be used soon after preparation.

Microstructured, functional PVA hydrogels through bioconjugation with oligopeptides under physiological conditions

In this work, bioconjugation techniques are developed to achieve peptide functionalization of poly(vinyl alcohol), PVA, as both a polymer in solution and within microstructured physical hydrogels, in both cases under physiological conditions. PVA is unique in that it is one of very few polymers with excellent biocompatibility and safety and has FDA approval for clinical uses in humans. However, decades of development have documented only scant opportunities in bioconjugation with PVA. As such, materials derived thereof fail to answer the call for functional biomaterials for advanced cell culture and tissue engineering applications. To address these limitations, PVA is synthesized with terminal thiol groups and conjugated with thiolated peptides using PVA in solution. Further, microstructured, surface-adhered PVA physical hydrogels are assembled, the available conjugation sites within the hydrogels are quantified, and quantitative kinetic data are collected on peptide conjugation to the hydrogels. The success of bioconjugation in the gel phase is quantified through the use of a cell-adhesive peptide and visualization of cell adhesion on PVA hydrogels as cell culture substrates. Taken together, the presented data establish a novel paradigm in bioconjugation and functionalization of PVA physical hydrogels. Coupled with an excellent safety profile of PVA, these results deliver a superior biomaterial for diverse biomedical applications.

Single vesicle analysis reveals nanoscale membrane curvature selective pore formation in lipid membranes by an antiviral α-helical peptide

Using tethered sub-100 nm lipid vesicles that mimic enveloped viruses with nanoscale membrane curvature, we have in this work designed a total internal reflection fluorescence microscopy-based single vesicle assay to investigate how an antiviral amphipathic α-helical (AH) peptide interacts with lipid membranes to induce membrane curvature-dependent pore formation and membrane destabilization. Based on a combination of statistics from single vesicle imaging, binding kinetics data, and theoretical analysis, we propose a mechanistic model that is consistent with the experimentally observed peptide association and pore formation kinetics at medically relevant peptide concentrations (10 nM to 1 μM) and unusually low peptide-to-lipid (P/L) ratio (~1/1000). Importantly, the preference of the AH peptide to selectively rupture virions with sub-100 nm diameters appears to be related to membrane strain-dependent pore formation rather than to previously observed nanoscale membrane curvature facilitated binding of AH peptides. Compared to other known proteins and peptides, the combination of low effective P/L ratio and high specificity for nm-sized membrane curvature lends this particular AH peptide great potential to serve as a framework for developing a highly specific and potent antiviral agent for prophylactic and therapeutic applications while avoiding toxic side effects against host cell membranes.