Search Results (98)

Background/Objectives: Oleosomes, plant-derived lipid nanostructures comprising a triacylglycerol core surrounded by a phospholipid monolayer and interfacial proteins, provide sustainable alternatives to synthetic lipid vesicles. This study compares solvent-free aqueous extractions of oleosomes from five nuts (almond, macadamia, walnut, hazelnut, pine) and five seeds (flaxseed, sunflower, hemp, sesame, canola/rapeseed) to understand how botanical origin influences composition and physicochemical behavior. Methods: Oleosomes were isolated using solvent-free aqueous extraction. Extraction yield, lipid content, protein content, particle size, polydispersity, and zeta potential were determined using standard analytical assays and dynamic light scattering techniques. SDS–PAGE was performed to evaluate interfacial protein profiles and oleosin abundance. Results: Extraction yields ranged from 8.4% (flaxseed) to 59.5% (walnut). Oleosome diameters spanned 424 nm to 3.9 µm, and all oleosome dispersions exhibited negative zeta potentials (–26 to –57 mV). SDS–PAGE revealed abundant 15–25 kDa oleosins in seed oleosomes but relatively sparse proteins in nut oleosomes. Seed oleosomes were smaller and exhibited stronger electrostatic stabilization, while nut oleosomes formed larger droplets stabilized primarily through steric interactions due to lower oleosin content. Conclusions: Variation in oleosin abundance and interfacial composition leads to distinct stabilization mechanisms in nut and seed oleosomes. These findings establish a predictive basis for tailoring oleosome size, stability, and functionality, and highlight their potential as natural nanocarriers for food, cosmetic, and pharmaceutical formulations. 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

Lipid droplet (LD) coalescence is a critical cellular process that reshapes lipid storage, drives metabolic disease progression, and dictates the stability of LD-mimetic drug carriers. However, the rate-limiting step—fusion of the phospholipid monolayers surrounding neutral-lipid cores—remains poorly quantified compared to bilayer fusion. Here, we quantitatively determine the activation barrier for LD coalescence by tracking the kinetics in protein-free adiposome models. Using a multi-technique approach combining time-resolved dynamic light scattering and small-angle X-ray scattering, we reveal that monolayer fusion is the kinetic bottleneck. We demonstrate that lipid composition is a powerful regulator of this barrier: cone-shaped lipids (e.g., dioleoylphosphatidylethanolamine) lower the barrier and promote fusion, while phosphatidylcholine-rich monolayers enhance stability. A continuum fusion model, adapted for curved monolayers, explains these results through changes in spontaneous curvature, hydration repulsion, and stalk energetics. Our findings establish composition-dependent design rules for controlling LD dynamics in metabolic health and for engineering stable or triggerable lipid-based delivery vehicles. Full article

Oleosomes are submicron oil bodies of a triacylglycerol core enveloped by a phospholipid monolayer and embedded proteins, forming a naturally assembled nanocarrier with exceptional oxidative resilience, interfacial stability, and biocompatibility. Their unique architecture supports solvent-free extraction, self-emulsification, and near-complete encapsulation of highly lipophilic compounds (log P > 4), including curcumin and cannabidiol, with reported efficiencies exceeding 95%. These plant-derived droplets enhance oral bioavailability through lymphatic uptake and enable targeted delivery strategies such as magnetically guided chemotherapy, which has reduced tumor burden by approximately 70% in vivo. The review critically examines recent advances in oleosome research, spanning botanical sourcing, green extraction technologies, interfacial engineering, xenobiotic encapsulation, pharmacokinetics, and therapeutic applications across oncology, dermatology, metabolic disease, and regenerative medicine. Comparative analyses demonstrate that oleosomes rival or surpass synthetic lipid nanocarriers in encapsulation efficiency, oxidative stability, and cost efficiency while offering a sustainable, clean-label alternative. Remaining challenges, including low loading of hydrophilic drugs, allergenicity, and regulatory standardization, are addressed through emerging strategies such as hybrid oleosome–liposome systems, recombinant oleosin engineering, and stimulus-responsive coatings. These advances position oleosomes as a versatile and scalable platform with significant potential for food, cosmetic, and pharmaceutical applications. Full article

Background/Objectives: This study aimed to enhance the oral delivery and therapeutic synergy of atorvastatin (AT) and docetaxel (DT) through a metronomic schedule using a transporter-targeted nanoemulsion (NE), with the goal of improving antitumor efficacy and immune modulation. Methods: AT and DT were co-encapsulated in a NE system (AT/DT-NE#E) incorporating deoxycholic acid–DOTAP (D-TAP), biotin-conjugated phospholipid (Biotin-PE), and d-α-tocopherol polyethylene glycol succinate (TPGS) to exploit bile acid and multivitamin transport pathways and inhibit P-glycoprotein efflux. The optimized NE was characterized physicochemically and evaluated for permeability in artificial membranes and Caco-2/HT29-MTX-E12 monolayers. Pharmacokinetics, tumor suppression, and immune cell infiltration were assessed in vivo using rat and CT26.CL25 mouse models. Results: AT/DT-NE#E showed enhanced permeability of AT and DT by 45.7- and 43.1-fold, respectively, across intestinal cell models and improved oral bioavailability by 118% and 376% compared to free drugs. In vivo, oral metronomic AT/DT-NE#E reduced tumor volume by 65.2%, outperforming intravenous AT/DT. Combination with anti-PD1 therapy achieved a 942% increase in tumor suppression over the control, accompanied by marked increases in tumor-infiltrating CD45⁺, CD4⁺CD3⁺, and CD8⁺CD3⁺ T cells. Conclusions: Oral metronomic administration of AT/DT via a dual-transporter-targeted NE significantly improves drug absorption, tumor inhibition, and immune response. This strategy presents a safe and effective approach for colon cancer therapy, particularly when combined with immunotherapy. Full article

Natural polysaccharides are biocompatible and biodegradable; therefore, they can be widely used in drug delivery, tissue engineering and wound healing. In this context, the interactions between polysaccharides, drugs and biological membranes are of great interest. In this paper, a 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) monolayer was used as a model membrane to study the interactions with polysaccharides: chitosan (Ch) and/or hyaluronic acid (HA) and a nonsteroidal anti-inflammatory drug (NSAID) naproxen (NAP). The changes in the physicochemical properties of the model membrane were characterized by means of the Langmuir monolayer technique combined with Brewster angle microscopy (BAM). Compression/adsorption isotherms and morphology images were obtained at 20 °C. They allowed us to determine the effect of the subphase type (Ch, HA, Ch–HA) on the behavior of DPPC monolayers in the absence and presence of NAP, their elasticity, morphology and stability as a function of time. A potential mode of interactions between the phospholipid, polysaccharides and drug responsible for the change in membrane properties was proposed. These interactions regulate the efficiency of drug delivery systems, being of importance for living organisms in pain relief and wound healing. Full article

Lipid droplets (LDs) are cytoplasmic organelles responsible primarily for the storage of neutral lipids, such as triacyclglycerols (TAGs). Derived from the endoplasmic reticulum bilayer, LDs are composed of a hydrophobic lipid core encased by a phospholipid monolayer and surface-associated proteins. To date, only a relatively few LD ‘coat’ proteins in plants have been identified and characterized, most of which come from studies of the model plant Arabidopsis thaliana. To expand our knowledge of the plant LD proteome, the LD-associated protein (LDAP) family from the tung tree (Vernicia fordii), whose seeds are rich in a commercially valuable TAG containing the conjugated fatty acid α-eleostearic acid (C18:3Δ^{9cis,11trans,13trans} [α-ESA]), was identified and characterized. Based on the tung tree transcriptome, three LDAP isoforms (VfLDAP1-3) were elucidated and the encoded proteins distinctly clustered into three clades along with their respective isoforms from other angiosperm species. Ectopic expression of the VfLDAPs in Nicotiana benthamiana leaves revealed that they localized specifically to LDs and influenced LD numbers and sizes, as well as increasing TAG content and altering TAG fatty acid composition. Interestingly, in a partially reconstructed TAG-ESA biosynthetic pathway, the co-expression of VfLDAP3 and, to a lesser degree, VfLDAP2, significantly increased the content of α-ESA stored within the LDs. These results suggest that the VfLDAPs can influence the steady-state content and composition of TAG in plant cells and that certain LDAP isoforms may have evolved to more efficiently package TAGs into LDs containing unusual fatty acids, such as α-ESA. Full article

Background: Elevated choline kinase alpha (ChoK) levels are observed in most solid tumors, including glioblastomas (GBM), and ChoK inhibitors have demonstrated limited efficacy in GBM models. Given that hypoxia is associated with resistance to GBM therapy, we hypothesized that tumor hypoxia could be responsible for the limited response. Therefore, we evaluated the effects of hypoxia on the function of JAS239, a potent ChoK inhibitor in four GBM cell lines. Methods: Rodent (F98 and 9L) and human (U-87 MG and U-251 MG) GBM cell lines were subjected to 72 h of hypoxic conditioning and treated with JAS239 for 24 h. NMR metabolomic measurements and analyses were performed to evaluate the signaling pathways involved. In addition, cell proliferation, cell cycle progression, and cell invasion parameters were measured in 2D cell monolayers as well as in 3D cell spheroids, with or without JAS239 treatment, in normoxic or hypoxic cells to assess the effect of hypoxia on JAS239 function. Results: Hypoxia and JAS239 treatment led to significant changes in the cellular metabolic pathways, specifically the phospholipid and glycolytic pathways, associated with a reduction in cell proliferation via induced cell cycle arrest. Interestingly, JAS239 also impaired GBM invasion. However, effects from JAS239 were variable depending on the cell line, reflecting the inherent heterogeneity of GBMs. Conclusions: Our findings indicate that JAS239 and hypoxia can deregulate cellular metabolism, inhibit cell proliferation, and alter cell invasion. These results may be useful for designing new therapeutic strategies based on ChoK inhibition, which can act on multiple pro-tumorigenic features. Full article

In this study, we explore the interactions between melittin, a cationic antimicrobial peptide, and model lipid membranes composed of the negatively charged phospholipids 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) and 1,2-dimyristoyl-sn-glycero-3-phosphoserine (DMPS). Using the Langmuir monolayer technique and atomic force microscopy (AFM), we reveal novel insights into these interactions. Our key finding is the observation of the ripple phase in the DMPS bilayer on mica, a phenomenon not previously reported for negatively charged single bilayers. This discovery is significant given the critical role of phosphatidylserine (PS) in cancer biology and the potential of melittin as an anticancer agent. We also highlight the importance of subphase composition, as melittin interacts preferentially with lipids in the liquid-condensed phase; thus, selecting the appropriate subphase composition is crucial because it affects lipid behavior and consequently melittin interactions. Our results show that melittin incorporates into lipid monolayers in both liquid-expanded and liquid-condensed phases, enhancing membrane fluidity and disorder, but is expelled from DMPS in the solid phase. AFM imaging further reveals that melittin induces substantial structural changes in the DMPG membrane and forms the ripple phase in the DMPS bilayers. Despite these alterations, melittin does not cause pore formation or membrane rupture, suggesting strong electrostatic adsorption on the membrane surface that prevents penetration. These findings highlight the differential impacts of melittin on lipid monolayers and bilayers and underscore its potential for interacting with membranes without causing disruption. Full article

Pronucleotides, after entering the cell, undergo chemical or enzymatic conversion into nucleotides with a free phosphate residue, and the released nucleoside 5′-monophosphate is then phosphorylated to the biologically active form, namely nucleoside 5′-triphosphate. The active form can inhibit HIV virus replication. For the most effective therapy, it is necessary to improve the transport of prodrugs into organelles. The introduction of new functional groups into their structure increases lipophilicity and, as a result, facilitates the interaction of pronucleotide molecules with components of biological membranes. Studies of these interactions were performed using the Langmuir technique. The prototype of the biological membrane was a thin monolayer composed of phospholipid molecules, DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine). The pronucleotides were 3′-azido-3′-deoxythymidine (AZT) analogs, formed by the phosphorylation of AZT to monophosphate (AZTMP) and containing various masking moieties that could increase their lipophilicity. Our results show the influence of the pronucleotide’s chemical structure on the fluidization of the model biomembrane. Changes in monolayer morphology in the presence of prodrugs were investigated by BAM microscopy. It was found that the incorporation of new groups into the structure of the drug as well as the concentration of AZT derivatives have a significant impact on the surface properties of the formed DPPC monolayer. Full article

Poly(butyl cyanoacrylate) (PBCA) nanoparticles have numerous applications, including drug and gene delivery, molecular imaging, and cancer therapy. To uncover the molecular mechanisms underlying their interactions with cell membranes, we utilized a Langmuir monolayer as a model membrane system. This approach enabled us to investigate the processes of penetration and reorganization of PBCA nanoparticles when deposited in a phospholipid monolayer subphase. Atomic force microscopy (AFM) was employed to visualize Langmuir–Blodgett (LB) films of these nanoparticles. Additionally, we examined the state of a monolayer of Pluronic F68, a stabilizer of PBCA nanoparticles in suspension, by measuring the changes in relative surface area and surface potential over time in the barostatic regime following PBCA suspension spreading. Based on these findings, we propose a molecular mechanism for nanoparticle reorganization at the air–water interface. Full article

Amphotericin B (AmB) causes toxicity to the erythrocyte membrane, leading to hemolysis, which limits the clinically effective dose for AmB intravenous therapy in invasive fungal infections. The molecular mechanism by which AmB adheres to the membrane of erythrocytes is the key factor in causing AmB to be toxic to the membrane of erythrocytes, but it is not yet fully understood; the mechanism by which AmB adheres to the liquid microdomains with higher fluidity formed by cholesterol and unsaturated phospholipids remains especially unclear. This study examined the adsorption of AmB at different concentrations, 5, 45, 85, and 125 $\mathsf{\mu }\mathrm{g}/\mathrm{m}\mathrm{L}$, on unsaturated phospholipid membranes containing 50 mol% cholesterol. The thermodynamic properties and structure of DOPC monolayers and DOPC/cholesterol mixed monolayers at different concentrations of AmB have been investigated using the Langmuir monolayer model and the BAM method. The impact of varying concentrations of AmB on the hydrophilic and hydrophobic domains of the DOPC bilayers and the DOPC/cholesterol mixed bilayers have also been discussed using large unilamellar vesicle liposomes and fluorescence techniques. It is shown that for AmB concentrations greater than 5 $\mathsf{\mu }\mathrm{g}/\mathrm{m}\mathrm{L}$, with an increase in AmB’s concentration, the reorganization time for the DOPC/cholesterol monolayer increases, and the elastic modulus of the DOPC/cholesterol mixed monolayer decreases. In particular, when AmB’s concentration is higher than 85$\mathsf{\mu }\mathrm{g}/\mathrm{m}\mathrm{L}$, the liquid-condensed phase domains on the DOPC/cholesterol monolayer reduce significantly and the liquid-expanded phase domain enlarges from the BAM images. When the AmB concentration reaches 5 $\mathsf{\mu }\mathrm{g}/\mathrm{m}\mathrm{L}$, the disorder of the hydrophobic and hydrophilic domains of the DOPC/cholesterol bilayer increases as the AmB concentration increases. The way in which AmB interacts with the DOPC/cholesterol mixed membrane is related to the concentration of AmB. The higher the concentration of AmB, the more likely it is to remove cholesterol from the unsaturated phospholipid membrane. The results are helpful to understand the mechanism of AmB’s toxicity to the erythrocyte’s membrane, which has a guiding value for seeking ways to reduce the AmB’s toxicity. Full article

The presented studies were aimed at determining the interactions in model membranes (Langmuir monolayers) created of phospholipids (PL) isolated from Legionella gormanii bacteria cultured with (PL + choline) or without (PL − choline) choline and to describe the impact of an antimicrobial peptide, human cathelicidin LL-37, on PL’s monolayer behavior. The addition of choline to the growth medium influenced the mutual proportions of phospholipids extracted from L. gormanii. Four classes of phospholipids—phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), cardiolipin (CL), and their mixtures—were used to register compression isotherms with or without the LL-37 peptide in the subphase. Based on them the excess area ($A_e$), excess ($\mathsf{\Delta }{G}_e$), and total ($\mathsf{\Delta }{G}_m$) Gibbs energy of mixing were determined. The thermodynamic analyses revealed that the PL − choline monolayer showed greater repulsive forces between molecules in comparison to the ideal system, while the PL + choline monolayer was characterized by greater attraction. The LL-37 peptide affected the strength of interactions between phospholipids’ molecules and reduced the monolayers stability. Accordingly, the changes in interactions in the model membranes allowed us to determine the difference in their susceptibility to the LL-37 peptide depending on the choline supplementation of bacterial culture. Full article

Doxorubicin (DOX) is a commonly used chemotherapeutic drug, from the anthracycline class, which is genotoxic to neoplastic cells via a DNA intercalation mechanism. It is effective and universal; however, it also causes numerous side effects. The most serious of them are cardiotoxicity and a decrease in the number of myeloid cells. For this reason, targeted DOX delivery systems are desirable, since they would allow lowering the drug dose and therefore limiting systemic side effects. Recently, synthetic dyes, in particular Congo red (CR), have been proposed as possible DOX carriers. CR is a planar molecule, built of a central biphenyl moiety and two substituted naphthalene rings, connected with diazo bonds. In water, it forms elongated ribbon-shaped supramolecular structures, which are able to selectively interact with immune complexes. In our previous studies, we have shown that CR aggregates can intercalate DOX molecules. In this way, they preclude DOX precipitation in water solutions and increase its uptake by MCF7 breast cancer cells. In the present work, we further explore the interactions between DOX, CR, and their aggregates (CR/DOX) with phospholipid membranes. In addition to neutral molecules, the protonated doxorubicin form, DXP, is also studied. Molecular dynamics simulations are employed to study the transfer of CR, DOX, DXP, and their aggregates through POPC bilayers. Interactions of CR, DOX, and CR/DOX with model monolayers are studied with Langmuir trough measurements. This study shows that CR may support the transfer of doxorubicin molecules into the bilayer. Both electrostatic and van der Waals interactions with lipids are important in this respect. The former promote the initial stages of the insertion process, the latter keep guest molecules inside the bilayer. Full article

Thymoquinone (TQ), a bioactive compound found in Nigella sativa seeds, possesses diverse therapeutic properties for skin conditions. However, formulating TQ presents challenges due to its hydrophobic nature and chemical instability, which hinder its skin penetration. Transethosomes, as a formulation, offer an environment conducive to enhancing TQ’s solubility, stability, and skin permeation. To optimize TQ transethosomal formulations, we introduced a combination of ionic and nonionic surfactants, namely Tween 20 and sodium lauryl sulfate (SLS) or sodium lauroyl glutamate (SLG). Surfactants play a crucial role in stabilizing the formulation, reducing aggregation, improving biocompatibility, and minimizing potential toxicity. We fine-tuned the formulation composition and gained insights into its interfacial behavior using the Langmuir monolayer technique. This method elucidated the interfacial properties and behavior of phospholipids in ethosome and transethosome formulations. Our findings suggest that monolayer studies can serve as the initial step in selecting surfactants for nanocarrier formulations based on their interfacial dilational rheology studies. It was found that the addition of surfactant to the formulation increased the elasticity considering the capability of transethosomes to significantly decrease their radius when permeating the skin barrier. The results of the dilational rheology experiments were most relevant to drug permeation through the skin for the largest amplitude of deformation. The combination of Tween 20 and SLS efficiently modified the rheological behavior of lipids, increasing their elasticity. This conclusion was supported by in vitro studies, where formulation F2 composed of Tween 20 and SLS demonstrated the highest permeation after 24 h (300.23 µg/cm²). Furthermore, the F2 formulation showed the highest encapsulation efficiency (EE) of 94%, surpassing those of the control and ethosomal formulations. Additionally, this transethosomal formulation exhibited antimicrobial activity against S. aureus, with a zone of inhibition of 26.4 ± 0.3 mm. Importantly, we assessed the cytotoxicity of both ethosomes and transethosomes at concentrations ranging from 3.5 µM to 50 µM on HaCaT cell lines and found no cytotoxic effects compared to TQ hydroethanolic solution. These results suggest the potential safety and efficacy of TQ transethosomal formulations. Full article