Search Results (359)

Cyclotides are exceptionally stable plant peptides whose biological activity is widely attributed to interactions with lipid membranes, yet the molecular mechanisms underlying these interactions remain incompletely resolved. Here, we employ microsecond-scale (1 μs) all-atom molecular dynamics simulations to investigate the membrane association of the cyclotide kalata B1 with phospholipid bilayers of distinct headgroup composition, including POPC, POPE, and POPG. This extended timescale enables full bilayer equilibration and allows observation of slower peptide-induced membrane responses that are not accessible in shorter simulations. Across all systems, kalata B1 rapidly adsorbs to the membrane surface and remains predominantly surface-associated throughout the simulations, while the cyclic cystine knot motif remains structurally intact, confirming the exceptional robustness of the cyclotide fold during membrane engagement. Lipid-dependent differences arise primarily from variations in peptide orientation, conformational flexibility, and interfacial dynamics rather than deep bilayer insertion or pore formation. Zwitterionic POPC membranes favor compact, upright peptide configurations, whereas POPE and POPG bilayers promote enhanced lateral spreading and dynamic reorganization driven by hydrogen bonding and electrostatic interactions, respectively. Leaflet-resolved analyses of lipid contacts, membrane thickness, and area per lipid reveal localized, asymmetric perturbations confined to the peptide-exposed leaflet, with no evidence of sustained bilayer thinning or global destabilization. Together, these results support an interfacial, headgroup-dependent mechanism of cyclotide membrane activity and reconcile previous experimental observations. This work provides molecular-level insight into lipid selectivity and early-stage cyclotide–membrane interactions that may inform future design of cyclotide-based bioactive agents. Full article

Kaurenoic acid (KA) is an ent-kaurane diterpenoid present in several medicinal plant species and has been reported to exhibit anti-inflammatory, cytotoxic, and analgesic activity in experimental models. Despite its pharmacological profile, the development of KA as a therapeutic agent has been hindered by its unfavorable physicochemical and biopharmaceutical properties. KA is highly lipophilic and poorly soluble in water, which limits its dissolution, systemic exposure, and oral bioavailability. These limitations are common among plant-derived bioactive compounds and pose significant challenges for clinical development. Lipid-based nanocarrier systems, particularly liposomal formulations, have therefore been investigated as potential delivery strategies for improving the biopharmaceutical performance of KA. Encapsulating KA within phospholipid bilayers can improve its apparent solubility, protect it from degradation, and modify its biodistribution compared to the free compound. In this review, we discuss the pharmacological mechanisms of KA, its physicochemical properties, and the biopharmaceutical barriers to its therapeutic development. We also critically evaluate published studies on nanocarrier-based formulations, focusing on encapsulation efficiency, particle size, release properties, and pharmacokinetics (PK). Additionally, regulatory and pharmaceutical considerations relevant to lipid-based delivery of KA are addressed. Available evidence supports lipid-based nanocarriers as a promising strategy to improve preclinical development and formulation performance of poorly soluble plant bioactives such as kaurenoic acid. Although KA-loaded nanocarriers demonstrate encouraging activity in preclinical models, comprehensive pharmacokinetic and safety evaluations remain necessary before clinical development can be realistically considered. Full article

Monoenoic fatty acids (MUFAs), defined by the presence of a single carbon–carbon double bond within a long aliphatic chain, constitute a structurally diverse and ecologically significant class of lipids widely distributed in aquatic organisms. In marine and freshwater environments, MUFAs are fundamental components of membrane phospholipids and storage lipids, where mono-unsaturation modulates melting point, lipid packing, and bilayer dynamics, enabling homeoviscous adaptation to fluctuations in temperature, pressure, salinity, and oxygen availability. Positional and geometric isomerism (e.g., cis-Δ5, Δ7, Δ9, Δ11, Δ13, and trans forms) further enhances biochemical diversity, providing sensitive chemotaxonomic markers and indicators of trophic transfer across food webs. In addition to common straight-chain monoenes, rare methyl-branched, cyclopropane-containing, and acetylenic derivatives occur in specialized aquatic taxa, reflecting evolutionary adaptation and ecological niche differentiation. Computational QSAR analyses suggest that monoenoic fatty acids and their unusual analogues occupy bioactivity spaces associated with lipid metabolism regulation, vascular and inflammatory modulation, antimicrobial defense, and membrane stabilization. This review integrates structural chemistry, biosynthesis, ecological distribution, trophic dynamics, and predicted biological activity of monoenoic fatty acids in aquatic systems, highlighting their dual role as adaptive membrane constituents and as biologically active mediators linking molecular lipid architecture to hydrobiological function and environmental change. Full article

Background: Plant-derived nanovesicles (PDNVs), a class of naturally occurring nanoparticles with a phospholipid bilayer structure, have attracted significant attention in biomedicine, particularly in anti-tumor research, due to their broad source availability, low production cost, high biocompatibility, and low immunogenicity. Methods: This review systematically summarizes and analyzes the isolation methods, composition, anti-tumor mechanisms, and clinical translation potential of PDNVs based on literature retrieved from PubMed and Web of Science, with clinical trials identified and categorized using ClinicalTrials.gov. Results: Current research has made impressive progress in the application of PDNVs, both as direct therapeutic agents and as drug delivery systems. Their remarkable stability, ability to cross physiological barriers (e.g., the gastrointestinal tract and blood–brain barrier), and engineerability underpin their versatile potential. Conclusions: This review comprehensively outlines the compositional characteristics of PDNVs and explores their multi-dimensional mechanisms and application prospects as natural therapeutics and drug delivery platforms in cancer therapy. Despite challenges such as standardization in preparation, PDNVs represent a highly promising class of novel nanobiomaterials. Full article

Silica particles are promising multifunctional drug delivery platforms; however, when in contact with blood or other biological fluids, proteins rapidly adsorb to their surface, forming the protein corona that modulates their biological interactions. In this study, silica microparticles were coated with lipid bilayers using two approaches: the lipid film hydration method and the on-particle solvent-assisted lipid coating (OPSALC) technique. We investigated how phospholipids with varying charges (zwitterionic, anionic, and cationic) and membrane phase influence coating formation and protein corona adsorption. The coating coverage and aggregation were characterized by fluorescence microscopy. The lipid film hydration method enabled coating with a broad range of lipids, but was highly dependent on the membrane phase and electrostatic interactions between lipid head group and particle surface. Pure anionic coatings were not achievable with this method; however, when combining the OPSALC method with a pre-silanization step, fully anionic coatings of silica microparticles were successfully obtained. Assessment by SDS-PAGE revealed differences in protein corona profiles modulated by the lipid compositions on the particles’ coatings. Overall, this study highlights the dependence of coating formation and protein corona composition on the phospholipid coatings’ properties. Full article

Catechins are characterized by a basic structure consisting of two benzene rings and a hydropyran heterocyclic ring. In (-)-epicatechin (ECT), the substituents in C2 and C3 of the dihydropyran ring are in cis conformation, whereas in (+)-catechin (CT), they are in trans conformation. Catechins tend to interact with membrane proteins, affecting their activity and/or function and metabolic processes. In this study, the impact of CT and ECT on erythrocyte membrane and cell functions was analyzed. Surprisingly, although the two compounds have a very similar structure that differs only in the orientation of the hydroxyl group in C3, they promote different effects on anion exchange through the phospholipid bilayer and on the release of ATP from cells. Anion transport mediated by Band 3 protein is reduced in the presence of CT compared with ECT which conversely increases it, and this observation aligns with the mechanisms of action we hypothesized in silico for the two compounds. Finally, ECT causes an increase in intracellular ATP levels unlike CT, and both molecules cause a decrease in ATP released from the erythrocyte. These findings could pave the way for further studies aimed at better understanding of the potential properties and structure–activity relationships of these molecules. Full article

Antimicrobial resistance represents not only a biological challenge but also a physicochemical limitation associated with antibiotic transport, membrane interaction, and local availability. In this preliminary study, a liposome-encapsulated doxycycline delivery system was developed using egg yolk-derived phospholipids, and its biophysical properties and release behavior were investigated. Phospholipids were isolated from egg yolk and used to prepare doxycycline-loaded liposomes via a thin-film hydration method combined with freeze–thaw processing. Liposome morphology was characterized by atomic force microscopy (AFM), while encapsulation efficiency was quantified by reversed-phase high-performance liquid chromatography (RP-HPLC). In vitro release kinetics were evaluated using a dialysis diffusion method, and antibacterial activity was assessed as a functional indicator of drug availability using minimum inhibitory concentration (MIC) assays against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). The prepared liposomes exhibited morphology with diameters of approximately 153 nm (PDI = 0.223). The encapsulation efficiency of doxycycline hyclate was 8.41%, and complete drug release was achieved within 48 h. Liposome-encapsulated doxycycline demonstrated a two-fold reduction in MIC values compared with free doxycycline. These findings offer preliminary insight to support further optimization and expanded investigation of liposome-encapsulated antibiotic delivery systems. Full article

Mechanosensitive ion channels (MSCs) are fundamental transducers that convert mechanical forces into electrochemical signals, enabling cells to regulate processes such as Ca²⁺ homeostasis, migration, proliferation, and adhesion. Located in both plasma and organellar membranes, MSCs, including Piezos, TRPs, K2Ps, MscL, and MscS families exhibit diverse ion selectivity, gating mechanisms and physiological roles. Emerging evidence demonstrates that lipids are dynamic regulators of MSC activation, sensitivity, and kinetics. Endogenous membrane lipids such as cholesterol, phospholipids, sphingolipids and fatty acids modulate MSC behavior by altering bilayer tension, curvature, stiffness and protein–lipid interactions. Exogenous lipids, including dietary fatty acids and lipid-derived metabolites, influence MSCs by modifying membrane physical properties or engaging specific lipid-binding sites on channel proteins. These interactions shape fundamental biological processes and contribute to disease mechanisms in cardiovascular dysfunction, neurological disorders, metabolic disease, and cancer. Despite significant progress, the molecular principles by which lipids regulate MSC conformational transitions and force sensing remain incompletely defined. This review synthesizes current knowledge on endogenous and exogenous lipid modulation of MSCs, integrating structural, computational and electrophysiological insights to highlight emerging therapeutic opportunities targeting lipid–mechanotransduction interfaces. Full article

Type 2 diabetes mellitus (T2DM) is a major metabolic disorder characterized by chronic hyperglycemia with far-reaching morbidities. Among these, diabetes-related cerebrovascular complications such as ischemic and hemorrhagic stroke, cerebral blood vessel disease, and vascular dementia are significant contributors to morbidity and mortality. Adipose tissue is a metabolically active endocrine organ that becomes dysfunctional in T2DM and communicates with distant tissues via secreted factors, including extracellular vesicles such as exosomes (EXs), phospholipid bilayer-enclosed nanosized particles. These adipocyte-derived exosomes (Ad-EXs) carry bioactive cargo, including lipids, proteins, and microRNAs that influence the function of distant organs, including the brain. Evidence indicates that Ad-EXs in T2DM are a significant risk factor for cerebrovascular complications via neurovascular impairment either directly through the adipose tissue–brain axis or indirectly by other organs. This review provides an overview of current knowledge on how Ad-EXs from different adipocyte populations contribute to cerebrovascular complications through oxidative stress, blood–brain barrier disruption, neuroinflammation, and mitochondrial dysfunction. Particular emphasis is placed on recent findings and gaps in knowledge linking diabetic Ad-EXs with brain microvascular endothelial cells that mediate neurovascular crosstalk, contributing to stroke susceptibility and cognitive decline. We also discuss the potential of Ad-EXs as biomarkers and therapeutic targets for cerebrovascular complications of T2DM. Full article

The combination of supported lipid bilayers (SLBs) with the Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) has been proven to be a powerful tool to simultaneously monitor mass and viscoelastic changes related to membrane binding-events. In this work, the above methodology is employed for the study of the interaction of the Early Endosomal Antigen 1 (EEA1) to a model lipid bilayer that mimics the early endosome (EE) membrane, focusing on the membrane composition. Starting with the formation of a lipid bilayer through the vesicles fusion technique, we investigated the formation of SLBs that incorporate phosphatidylinositol 3-phosphate (PI(3)P), a key component for EEA1 binding, in combination with other lipids, e.g., (1,2-dioleoyl-sn-glycero-3)-phosphocholine (DOPC), -phosphoserine (DOPS), -phosphoethanolamine (DOPE), and cholesterol (Chol). The interaction of the full-length coiled-coil EEA1 to the formed SLBs was further studied in real time with the QCM-D and characterized with respect to the lipid composition and pH. Our findings confirm that PI(3)P is essential for the EEA1–membrane interaction, while it was shown that Chol and phosphatidylserine greatly influence the binding event. In fact, including 30% Chol in a PI(3)P (3%):PS (6%) SLB resulted in almost double EEA1 binding than in the absence of Chol. Moreover, we employed the QCM-viscoelastic model available to analyze the QCM-D data with emphasis on the study of the protein conformation. Our results showed that, in our in vitro system, EEA1 is not fully extended and/or highly packed, but is mainly in a bent, distorted conformation with an average size close to 100 nm. This study complements previous works employing in vitro assays, also demonstrating the ability to reconstitute more complex biomimetic EE membranes containing inositol phospholipids on a QCM surface for the study of EEA1 binding. Full article

Porcine epidemic diarrhea virus (PEDV) has emerged as a major pathogen responsible for porcine diarrheal diseases, causing outbreaks of severe diarrhea and high mortality in neonatal piglets, thereby inflicting severe economic losses on the global swine industry. Current commercial PED vaccines, comprising conventional inactivated and live attenuated formulations, have exhibited progressively diminished efficacy in the face of emerging PEDV variants. The development of high-efficiency vaccine platforms is therefore critical for PED control. This study engineered a cellular membrane nanovesicle (CMN)-based vaccine, which differs from existing inactivated or subunit vaccines by presenting the PEDV spike (S) protein on the cell membranes to mimic the bilayer phospholipid structure of the viral envelope. The full-length S protein (FS, aa 19-1309) or a truncated S protein fragment (TS, aa 19-726) was expressed in Expi293F cells, followed by extraction of cell membranes to assemble antigen-displaying CMN vaccines. Compared with commercial live attenuated vaccine, administration of the CMN vaccine elicited high-titer neutralizing antibodies and elevated IFN-γ-producing CD8⁺ T cells in murine studies. Safety assessments revealed no adverse effects on body weight, hepatic/renal function indices, or histopathological parameters in vaccinated mice. Furthermore, immunization of piglets elicited notable humoral and CD8⁺ T cell immune responses. Collectively, the strategy of CMN-based vaccine described herein delivers a potential PEDV vaccine platform, thereby offering a novel avenue for next-generation veterinary vaccine development. Full article

Background/Objectives: Neovascularization, defined as the sprouting of new blood vessels from pre-existing vasculature, is a critical pathological feature in ocular diseases such as pathological myopia and represents a leading cause of corneal vision loss. Vascular endothelial growth factor A (VEGFA) plays a pivotal role in endothelial cell proliferation, migration, survival by anti-apoptotic signaling, and vascular permeability. Dysregulation of VEGFA is closely linked to pathological neovascularization. Exosomes, nanosized phospholipid bilayer vesicles ranging from 30 to 150 nm, have emerged as promising gene delivery vehicles due to their intrinsic low immunogenicity, superior cellular uptake, and enhanced in vivo stability. This study aimed to investigate whether highly purified mesenchymal stem cell (MSC)-derived exosomes loaded with VEGFA siRNA labeled with FAM can effectively suppress pathological corneal neovascularization (CNV) via targeeted cellular transduction and VEGFA inhibition. Furthermore, we examined whether the therapeutic effect involves the modulation of the PI3K–Akt–Caspase-3 signaling axis. Methods: Exosomes purified by chromatography were characterized by electronmicroscopy, standard marker immunoblotting, and nanoparticle tracking analysis. In vitro, we assessed exosome uptake and cytoplasmic release, suppression of VEGFA mRNA/protein, cell viability, and apoptosis. In a mouse CNV model, we evaluated tissue reach and stromal retention after repeated intrastromal injections; anterior segment angiogenic indices; CD31/VEGFA immunofluorescence/immunoblotting; phosphorylated PI3K and Akt; cleaved caspase-3; histology (H&E); and systemic safety (liver, kidney, and spleen). Results: Exosomes were of high quality and showed peak efficacy at 48 h, with decreased VEGFA mRNA/protein, reduced viability, and increased apoptosis in vitro. In vivo, efficient delivery and stromal retention were observed, with accelerated inhibition of neovascularization after Day 14 and maximal effect on Days 17–19. Treatment reduced CD31 and VEGFA, decreased p-PI3K and p-Akt, and increased cleaved caspase-3. Histologically, concurrent reductions in neovascularization, inflammatory cell infiltration, and inflammatory epithelial thickening were observed, alongside a favorable systemic safety profile. Conclusions:VEGFA siRNA-loaded exosomes effectively reduce pathological CNV via a causal sequence of intracellular uptake, cytoplasmic release, targeted inhibition, and phenotypic suppression. Supported by consistent PI3K–Akt inhibition and caspase-3–mediated apoptosis induction, these exosomes represent a promising local gene therapy that can complement existing antibody-based treatments. Full article

The permeation of different chemical substances across the membrane is of utmost importance to the life and health of a living cell. Depending on the nature of the permeant, the process is mediated by either the protein (e.g., membrane channels) or lipid phases of the membrane, or both. In the case of small and physiologically important gas molecules, namely O₂ and CO₂, the literature supports the involvement of both pathways in their transport. The extent of involvement of the lipid phase, however, is directly dependent on the nature of the lipid constituents of the membrane that determine its various structural and physicochemical properties. In this study, we use molecular dynamics simulation, as a method with sufficient spatial and temporal resolutions, to analyze these properties in heterogeneous lipid bilayers, composed of phospholipids with varied tails, sphingomyelin, and cholesterol, to different degrees. Together with the calculation of the free energy profiles, diffusion constants, and gas diffusivity, the results shed light on the importance of the lipid phase of membranes in gas transport rate and how they can be modulated by their lipid composition. Full article

Achieving a high nutritional value of food often involves fortifying microorganisms (such as bacteria and yeast) used in baking and dairy industry with essential elements. The aim of this study was to investigate the effect of a pulsed electric field (PEF) on the penetration and accumulation of Ca²⁺ and Mg²⁺ ions into model membranes of the food-grade yeast Saccharomyces cerevisiae. Simplified model membranes (monolayers and liposomes) were constructed using the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC). The Langmuir monolayer technique, dynamic light scattering (DLS) and microelectrophoresis were employed to characterize the physicochemical properties of the model membranes investigated. The results showed significant molecular-level differences in the interactions of the selected cations with lipid monolayers and bilayers in liposome structures. Both cations deeply penetrated the membrane’s hydrophilic region, yet two competing effects were evident: expansion induced by hydrated Mg²⁺ and condensation driven by Ca²⁺ bridging. Furthermore, the application of PEF increased the concentration of ions absorbed by the liposomes. Specifically, optimized PEF parameters resulted in cation accumulation within the model membranes, ranging from 6 to 13%. This finding correlates well with the increased Ca²⁺ and Mg²⁺ uptake observed in real yeast cells, providing a deeper understanding of the cell membrane-environment interface and the underlying processes. Full article

Calcium (Ca²⁺) is a signal messenger for ion flow in and out of microbial, parasitic, and host defense cells. Manipulation of calcium ion signaling with ion blockers and calcineurin inhibitors may improve host defense while decreasing microbial/parasitic resistance to therapy. Ca²⁺ release from intracellular storage sites controls many host defense functions (cell integrity, movement, and growth). The transformation of phospholipids in the erythrocyte membrane is associated with changes in deformability. This type of lipid bilayer defense mechanism helps to prevent attack by Plasmodium. Patients with sickle cell disease (SS hemoglobin) do not have this protection and are extremely vulnerable to massive hemolysis from parasitic infestation. Patients with thalassemia major also lack parasite protection. Alteration of Ca²⁺ ion channels responsive to environmental stimuli (transient receptor potential) results in erythrocyte protection from Plasmodium. Similarly, calcineurin inhibitors (cyclosporine) reduce heart and brain inflammation injury with Trypanosoma and Taenia. Ca²⁺ channel blockers interfere with malarial life cycles. Several species of parasites are known to invade hepatocytes: Plasmodium, Echinococcus, Schistosoma, Taenia, and Toxoplasma. Ligand-specific membrane channel constituents (inositol triphosphate and sphingosine phospholipid) constitute membrane surface signal messengers. Plasmodium requires Ca²⁺ for energy to grow and to occupy red blood cells. A cascade of signals proceeds from Ca²⁺ to two proteins: calmodulin and calcineurin. Inhibitors of calmodulin were found to blunt the population growth of Plasmodium. An inhibitor of calcineurin (cyclosporine) was found to retard population growth of both Plasmodium and Schistosoma. Calcineurin also controls sensitivity and resistance to antibiotics. After exposure to cyclosporine, the liver directs Ca²⁺ ions into storage sites in the endoplasmic reticulum and mitochondria. Storage of large amounts of Ca²⁺ would be useful if pathogens began to occupy both red blood cells and liver cells. We present scientific evidence supporting the benefits of calcium channel blockers and calcineurin inhibitors to potentiate current antiparasitic therapies. Full article