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Plasmonic Gold Templates Enhancing Single Cell Lipidomic Analysis of Microorganisms
摘要： Single cell lipid profiling is a powerful tool to connect membrane composition and its changes within individual cells to specific biochemical functions or stimuli, but current approaches are inadequate due to the complex nature of the cells and technical limitation in analysis. Herein we report a new method with plasmonic substrates capable of cell localization and enhanced lipid ionization through thin-gold-film MALDI-MS. We performed lipidomic profiling of algae single cells with a 120-well microarray and identified more than 50 lipids in C. reinhardtii without an extraction process. The substrate was used for probing toxicological effect of herbicide atrazine on the algae’s lipidome, demonstrating molecular changes in glycerol lipid profiles. Fast location of cells with metal-enhanced fluorescence (MEF) and subsequent precise and direct ionization of the LDI process contribute to the enhanced performance, allowing for assessment of lipid changes concurrent with atrazine affected populations. This method that combines microarrays, MEF and MALDI-MS presents an effective platform for lipidomic study of single cells and for environmental toxicity study with microorganisms.
关键词： plasmonic substrates,MALDI-MS,atrazine,environmental toxicity,lipidomic profiling,single cell lipid profiling
更新于2025-09-16 10:30:52
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Randomised double-masked placebo-controlled trial of the cumulative treatment efficacy profile of intense pulsed light therapy for meibomian gland dysfunction
摘要： Purpose: To assess long-term cumulative treatment effects of intense pulsed light (IPL) therapy in meibomian gland dysfunction (MGD). Methods: Eighty-seven symptomatic participants (58 female, mean±SD age, 53±16 years) with clinical signs of MGD were enrolled in a prospective, double-masked, parallel-group, randomised, placebo-controlled trial. Participants were randomised to receive either four or five homogeneously sequenced light pulses or placebo treatment to both eyes, (E-Eye Intense Regulated Pulsed Light, E-Swin, France). Visual acuity, dry eye symptomology, tear film parameters, and ocular surface characteristics were assessed immediately before treatment on days 0, 15, 45, 75, and four weeks after treatment course completion on day 105. Inflammatory and goblet cell function marker expression, and eyelid swab microbiology cultures were evaluated at baseline and day 105. Results: Significant decreases in OSDI, SPEED, and SANDE symptomology scores, and meibomian gland capping, accompanied by increased tear film lipid layer thickness, and inhibited Corynebacterium macginleyi growth were observed in both treatment groups (all p<0.05). Sustained clinical improvements occurred in both treatment groups from day 75, although significant changes from day 45, in lipid layer quality, meibomian gland capping, OSDI and SANDE symptomology, were limited to the five-flash group (all p<0.05). Conclusions: IPL therapy effected significant improvements in dry eye symptomology, tear film lipid layer thickness, and meibomian gland capping in MGD patients. Five-flash IPL treatment showed superior clinical efficacy to four-flash, and an initial course of at least four treatments is suggested to allow for establishment of sustained cumulative therapeutic benefits prior to evaluation of overall treatment efficacy.
关键词： lipid layer,Intense pulsed light,ocular surface,dry eye,tear film,meibomian gland
更新于2025-09-16 10:30:52
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Immobilization of natural lipid biomembranes and their interactions with choline carboxylates. A nanoplasmonic sensing study
摘要： The cell membrane is mainly composed of lipid bilayers with inserted proteins and carbohydrates. Lipid bilayers made of purified or synthetic lipids are widely used for estimating the effect of target compounds on cell membranes. However, the composition of such biomimetic membranes is much simpler than the composition of biological membranes. Interactions between compounds and simple composition biomimetic membranes might not demonstrate the effect of target compounds as precisely as membranes with compositions close to real organisms. Therefore, the aim of our study is to construct biomimetic membrane closely mimicking the state of natural membranes. Liposomes were prepared from lipids extracted from L-α-phosphatidylcholine, Escherichia coli, yeast (Saccharomyces cerevisiae) and bovine liver cells through agitation and sonication. They were immobilized onto SiO2 sensor surfaces using N-(2-hydroxyethyl)piperazine-N’-2-ethanesulfonic acid buffer with calcium chloride. The biomimetic membranes were successfully immobilized onto the SiO2 sensor surface and detected by nanoplasmonic sensing. The immobilized membranes were exposed to choline carboxylates. The membrane disruption effect was, as expected, more pronounced with increasing carbohydrate chain length of the carboxylates. The results correlated with the toxicity values determined using Vibrio fischeri bacteria. The yeast extracted lipid membranes had the strongest response to introduction of choline laurate while the bovine liver lipid extracted liposomes were the most sensitive towards the shorter choline carboxylates. This implies that the composition of the cell membrane plays a crucial role upon interaction with choline carboxylates, and underlines the necessity of testing membrane systems of different origin to obtain an overall image of such interactions.
关键词： natural lipid biomembrane,interaction,nanoplasmonic sensing,immobilization,choline carboxylate,ionic liquid
更新于2025-09-12 10:27:22
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Plasmonic Nanoparticle-Interfaced Lipid Bilayer Membranes
摘要： Plasmonic nanoparticles are widely exploited in diverse bioapplications ranging from therapeutics to biosensing and biocomputing because of their strong and tunable light?matter interactions, facile and versatile chemical/biological ligand modifications, and biocompatibility. With the rapid growth of nanobiotechnology, understanding dynamic interactions between nanoparticles and biological systems at the molecular or single-particle level is becoming increasingly important for interrogating biological systems with functional nanostructures and for developing nanoparticle-based biosensors and therapeutic agents. Therefore, significant efforts have been devoted to precisely design and create nano?bio interfaces by manipulating the nanoparticles’ size, shape, and surface ligand interactions with complex biological systems to maximize their performance and avoid unwanted responses, such as their agglomeration and cytotoxicity. However, investigating physicochemical interactions at the nano?bio interfaces in a quantitative and controllable manner remains challenging, as the interfaces involve highly complex networks between nanoparticles, biomolecules, and cells across multiple scales, each with a myriad of different chemical and biological interactions.
关键词： Plasmonic nanoparticles,lipid bilayer membranes,therapeutics,biocomputing,nano?bio interfaces,biosensing
更新于2025-09-12 10:27:22
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Design of arrayed-waveguide optical switch employing window function for crosstalk reduction
摘要： Nanosheets have thicknesses on the order of nanometers and planar dimensions in the micrometer range. Nanomaterials that are capable of converting reversibly between 2D nanosheets and 3D structures in response to specific triggers can enable construction of nanodevices. Supra-molecular lipid nanosheets and their triggered conversions to 3D structures including vesicles and cups are reported. They are produced from lipid vesicles upon addition of amphiphilic peptides and cationic copolymers that act as peptide chaperones. By regulation of the chaperoning activity of the copolymer, 2D to 3D conversions are reversibly triggered, allowing tuning of lipid bilayer structures and functionalities.
关键词： graft copolymers,amphiphilic peptides,2D–3D conversion,lipid nanosheets
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Plasmonic Heating of Gold Nanoparticles for Controlling of Current across Lipid Membranes in Modulating Neuronal Behavior Applications
摘要： Electrophysiology is a golden method for the study of the nervous system. However, electrical stimulation has to deal with multiple challenges, including selectivity, spatial resolution, mechanical stability, and implant-induced injury. Optical stimulation techniques may avoid some of these challenges by providing more selective stimulation, higher spatial resolution and reduced invasiveness of the device. Optogenetics is a technique to introduce light-sensitive ion channels to neurons for optical stimulating of them with tight spatial and temporal confinement. While optogenetics provides a powerful tool for studying neural functions, the main limitation for clinical applications is gen expiration. One current status of the optical stimulation technique is using nanoparticles (NPs) for temperature manipulation of neural cells at the nanoscale. Nanoabsorbers like gold nanoparticles (AuNPs) when irradiated at their plasmon resonance, AuNPs heat up rapidly and confer this heat to the plasma membrane. Laser irradiation of light-absorbing AuNPs transiently increases cell membrane permeability [1]. Here, we present an investigation of the interaction patterns of AuNPs with diameters from 10 and 50 nm with artificial membranes which local plasmonic heating of AuNPs can be utilized to regulate membrane currents and conductance situations of membranes. In this study, the black lipid membrane (BLM) as an artificial planar lipid membranes were used. BLM experiments were accomplished using a small Teflon chamber with two compartments (cis and trans) are separated by a small aperture onto which the lipid bilayer membrane is formed. The compartments are each filled with a different concentration of KCl as an electrolyte solution. The membrane current (I) was measured through silver/silver-chloride electrodes inserted into the aqueous salt solutions on both sides of the membrane, using a current-to-voltage converter[2]. To study the effects of NPs with different sizes on the cell membranes, the diphytanoyl-phosphatidylcholine (DiphPC) lipid were selected as bilayer membranes. AuNPs with different sizes and concentrations were always added to the cis-side of the membrane. AuNPs were plunged into the solution after a short time a laser with a wavelength of λ = 532 nm was focused on the hole. The laser power for all experiment was set to be 50 mW. In our experiments, light sources consist of both continuous and pulse irradiations. The obtained results show the amount of current that ?ows through a bilayer membrane was 17 and 10 pA for a continuous and pulse irradiation to the NPs with size 50 nm, respectively. While in the same experimental conditions heating of NPs with the size 10 nm leads to the current pass of membrane equal to 12 and 8pA, respectively.
关键词： Lipid Membranes,Neuronal Behavior,Plasmonic Heating,Optical Stimulation,Gold Nanoparticles
更新于2025-09-11 14:15:04
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AIP Conference Proceedings [AIP Publishing 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Fes, Morocco (25–27 March 2019)] 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Solid lipid nanoparticles made of self-emulsifying lipids for efficient encapsulation of hydrophilic substances
摘要： In the last decades, most attention has been paid to solid lipid nanoparticles (SLN) as nanocarriers for pharmaceutical purposes due to their low toxicity, possible production on large scale and delivery of active principles by several administration routes. For example, lung delivery will necessitate direct administration, e.g. by aerosolisation, to maximize deposition into the airways and minimize systemic side effects. However, SLN based on common solid lipids preferentially incorporate lipophilic drugs, while the hydrophilic ones are loaded in low amount. To overcome this drawback, it seemed interesting to evaluate SLN based on self-emulsifying (SE) lipids, which are mixtures of lipids, surfactant and cosurfactants able to form emulsions in contact with aqueous media. Thus, we evaluated the preparation of SLN based on Gelucire? 50/13, selected as a SE lipid model, encapsulating glutathione (GSH) or proanthocyanidins occurring in grape seed extract (GSE), as hydrophilic model substances according to the melt-emulsification method. The encapsulation efficiency of such GSH- or GSE-SLN resulted satisfactory for both the hydrophilic compounds examined. However, to draw definitive conclusions on the scope and limitations of this approach based on SE lipids, further studies are necessary. Moreover, GSH-SLN were investigated for their performance in delivering the antioxidant peptide to immunocompetent fish cells, while GSE-SLN were evaluated for their possible application in the treatment of pulmonary diseases. It was found that GSH-SLN were not internalized by fish cells, while GSE-SLN showed favorable properties for lung delivery.
关键词： lung delivery,proanthocyanidins,solid lipid nanoparticles,self-emulsifying lipids,hydrophilic substances,encapsulation,glutathione
更新于2025-09-11 14:15:04
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Self‐assembly of lipid rafts revealed by fluorescence correlation spectroscopy in living breast cancer cells
摘要： In the study, imaging this polarisation Lipids and proteins in the plasma membrane are laterally heterogeneous and formalised as lipid rafts featuring unique biophysical properties. However, self-assembly mechanism of lipid raft cannot be revealed even its physical properties and components were determined in specific physiological two-photon processes. generalised and fluorescence correlation spectroscopy were used to study the fusion of lipid rafts through the membrane phase and the lateral diffusion of lipids in living breast cancer cells. A self-assembly model of lipid rafts and lipid associated with to phase was membrane demonstrate the lipid sorting ability of lipid rafts in the plasma membrane. The results showed that the increased proportion of slow subdiffusion of GM1-binding cholera toxin B-subunit (CT-B) is accompanied with an increased liquid-ordered domain during the β-estradiol-induced fusion of lipid rafts. And slow subdiffusion of CT-B was vanished with the depletion of lipid rafts. Whereas the dialkylindocarbocyanine (DiIC18) diffusion was not specifically regulated by lipid rafts. This study will open up a new insight for uncovering the self-assembly of lipid rafts in specific pathophysiological processes.
关键词： Lipid rafts,Self-assembly,Membrane phase,Fluorescence correlation spectroscopy,Anomalous diffusion
更新于2025-09-11 14:15:04
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A Combination of Visudyne and a Lipid-Anchored Liposomal Formulation of Benzoporphyrin Derivative Enhances Photodynamic Therapy Efficacy in a 3D Model for Ovarian Cancer
摘要： A major objective in developing new treatment approaches for lethal tumors is to reduce toxicity to normal tissues while maintaining therapeutic efficacy. Photodynamic therapy (PDT) provides a mechanistically-distinct approach to treat tumors without the systemic toxicity of chemotherapy drugs. PDT involves the light-based activation of a small molecule, a photosensitizer (PS), to generate reactive molecular species (RMS) that are toxic to target tissue. Depending on the PS localization, various cellular and subcellular components can be targeted, causing selective photodamage. It has been shown that targeted lysosomal photodamage followed by, or simultaneous with, mitochondrial photodamage using two different PS results in a considerable enhancement in PDT efficacy. Here, two liposomal formulations of benzoporphyrin derivative (BPD): 1. Visudyne (clinically-approved) and 2. an in-house formulation entrapping a lipid-conjugate of BPD, are used in combination to direct PS localization to mitochondria, endoplasmic reticulum and lysosomes, enabling simultaneous photodamage to all three organelles using a single wavelength of light. Building on findings by our group, and others, this study demonstrates, for the first time in a 3D model for ovarian cancer, that BPD-mediated photodestruction of lysosomes and mitochondria/ ER significantly enhances PDT efficacy at lower light doses than treatment with either PS formulation alone.
关键词： mitochondrial photodamage,benzoporphyrin derivative,Photodynamic therapy (PDT),liposome,dual photosensitizer,lipid-anchored,lysosomal photodamage,Visudyne,3D tumor model,ovarian cancer
更新于2025-09-11 14:15:04
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The Ability of Functionalized Fullerenes and Surface Modified TiO <sub/>2</sub> Nanoparticles to Photosensitize Peroxidation of Lipids in Selected Model Systems
摘要： Photochemical properties of a new class of inorganic nanoparticles, namely a cationic C60 fullerene substituted with three quaternary pyrrolidinium groups (BB6) and a surface modified nanocrystalline TiO2 with bromopyrogallol red (Brp@TiO2) were examined for their effectiveness in photogenerating singlet oxygen and free radicals. In particular, their ability to photosensitize peroxidation of unsaturated lipids was analyzed in POPC:cholesterol liposomes and B16 mouse melanoma cells employing a range of spectroscopic and analytical methods. Because melanoma cells typically are pigmented, we examined the effect of melanin on the photosensitized peroxidation of lipids in liposomes and B16 melanoma cells, mediated by BB6 and Brp@TiO2 nanoparticles. The obtained results suggest that peroxidation of unsaturated lipids, photosensitized by BB6 occurs mainly, although not exclusively, via Type II mechanism involving singlet oxygen. On the other hand, if surface modified TiO2 is used as a photosensitizer, Type I mechanism of lipid peroxidation dominates, as indicated by the predominant formation of the free-radical dependent cholesterol oxidation products. The protective effect of melanin was particularly evident when BB6 was used as a photosensitizer, suggesting that melanin could efficiently interfere with Type II processes.
关键词： Lipid peroxidation,Melanin,Fullerenes,Singlet oxygen,TiO2 nanoparticles,Free radicals,Photodynamic therapy
更新于2025-09-10 09:29:36