Download or read book Interaction of Amphiphilic Nanoparticles with Structurally Perturbed Lipid Membranes written by Alexander W. Derry and published by . This book was released on 2018 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the interactions between nanoparticles and lipid membranes is important for applications such as drug delivery and membrane-protein mimetics. Perturbations such as area asymmetry and lateral tension affect these interactions by inducing various structural changes to the membranes. We use molecular dynamics simulations to demonstrate that the introduction of area asymmetry to a bilayer membrane significantly decreases the insertion latency of amphiphilic gold nanoparticles into both the densely and sparsely packed leaflets. We further demonstrate using transition state analysis that the dominant mechanisms for insertion into the dense and sparse leaflets are lipid desorption and lipid tail protrusions, respectively. These findings are supported by potential of mean force calculations showing that the energy barrier to protrusion is lower in the sparse leaflet, while that of desorption is lower in the dense leaflet. We also demonstrate that the structural characteristics of the bilayer when subject to lateral tension are similar to that observed in membranes with area asymmetry, suggesting a similar reduction in insertion latency. Further, we observe that lateral tension also increases the likelihood of nanoparticle ligands flipping across the bilayer, which is necessary for the nanoparticle adopting a stable symmetric configuration in the membrane.

Download or read book Interaction of Amphiphilic Nanoparticles with Model and Bacterial Membranes written by Jared Thomas Wiemann and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this doctoral work, we aimed to understand how amphiphilic nanoparticles, especially those with anisotropic surface chemistry, interact with biological membranes. Specifically, our overall goal was to elucidate the cytotoxic and antibacterial properties of anisotropic particles relative to amphiphilic nanoparticles with uniform surface chemistry. Nanoparticles with anisotropic surface chemistry have been synthesized for uses in sensing and immunotherapy, among other uses. In our early studies, we evaluated the impact of amphiphilic particles against free-standing biomimetic membranes to assess their potential cytotoxicity. Using "two-faced" amphiphilic Janus nanoparticles, which display separated hydrophobic and hydrophilic sides, we observed that anisotropic surface chemistry enhances the binding of particles to lipid membranes which leads to poration, membrane wrinkling, protrusions, and even collapse of entire membranes. Building upon these findings, we further observed that Janus nanoparticles selectively bind to liquid disordered domains in phase-separated lipid membranes. Extraction of lipids from liquid disordered domains to the hydrophobic nanoparticle hemispheres led to membrane compression and bulging of liquid ordered domains. These studies revealed the distinct consequences of anisotropic amphiphilic nanoparticles on lipid membrane integrity and structure. In the final part of this work, we investigated the antimicrobial properties of amphiphilic Janus nanoparticles. As more multidrug resistant bacteria emerge and fewer antibiotics are developed for clinical use, antibiotic resistance remains an increasing threat to public health. Researchers have since turned to nanomaterials with tailored surface chemistry to evade mechanisms of antibiotic resistance by directly disrupting lipid membranes and cell walls, often times using uniform coatings of cationic or amphiphilic ligands on particle surfaces. Given the potential enhanced antibiotic properties of Janus nanoparticles based on our first works, we fabricated "two-faced" amphiphilic Janus nanoparticles with one hemisphere of the Janus nanoparticles functionalized with hydrophobic alkyl chains and the other hemisphere of the nanoparticles functionalized with either a cationic antibiotic drug, colistin, or a cationic poly(amidoamine) (PAMAM) dendrimer that is not an antibiotic drug. We show that both the colistin/hydrophobic Janus nanoparticles and dendrimer/hydrophobic Janus nanoparticles effectively inhibit the growth of both Gram-negative and Gram-positive bacteria at picomolar concentrations. The half-maximum effective concentrations (EC50) of those cationic/hydrophobic Janus nanoparticles against a variety of bacteria are in the picomolar range and significantly lower than those of conventional nanoparticles with uniform surface chemistry. The Janus nanoparticles inhibit bacterial growth by disrupting bacterial membranes and by inducing reactive oxygen species (ROS). Our results demonstrate that the design of the segregated hydrophobic and cationic charges on the nanoparticle surface is key for their antibiotic potency. The antibiotic potency of the Janus nanoparticles is applicable to cationic ligands and not limited to cationic antibiotic molecules. Those anisotropic amphiphilic Janus nanoparticles are promising new broad-spectrum antibiotic nanoparticles.

Download or read book Interaction of Amphphilic Nanoparticles with Model and Bacterial Membranes written by Jared Thomas Wiemann and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this doctoral work, we aimed to understand how amphiphilic nanoparticles, especially those with anisotropic surface chemistry, interact with biological membranes. Specifically, our overall goal was to elucidate the cytotoxic and antibacterial properties of anisotropic particles relative to amphiphilic nanoparticles with uniform surface chemistry. Nanoparticles with anisotropic surface chemistry have been synthesized for uses in sensing and immunotherapy, among other uses. In our early studies, we evaluated the impact of amphiphilic particles against free-standing biomimetic membranes to assess their potential cytotoxicity. Using “two-faced” amphiphilic Janus nanoparticles, which display separated hydrophobic and hydrophilic sides, we observed that anisotropic surface chemistry enhances the binding of particles to lipid membranes which leads to poration, membrane wrinkling, protrusions, and even collapse of entire membranes. Building upon these findings, we further observed that Janus nanoparticles selectively bind to liquid disordered domains in phase-separated lipid membranes. Extraction of lipids from liquid disordered domains to the hydrophobic nanoparticle hemispheres led to membrane compression and bulging of liquid ordered domains. These studies revealed the distinct consequences of anisotropic amphiphilic nanoparticles on lipid membrane integrity and structure. In the final part of this work, we investigated the antimicrobial properties of amphiphilic Janus nanoparticles. As more multidrug resistant bacteria emerge and fewer antibiotics are developed for clinical use, antibiotic resistance remains an increasing threat to public health. Researchers have since turned to nanomaterials with tailored surface chemistry to evade mechanisms of antibiotic resistance by directly disrupting lipid membranes and cell walls, often times using uniform coatings of cationic or amphiphilic ligands on particle surfaces. Given the potential enhanced antibiotic properties of Janus nanoparticles based on our first works, we fabricated “two-faced” amphiphilic Janus nanoparticles with one hemisphere of the Janus nanoparticles functionalized with hydrophobic alkyl chains and the other hemisphere of the nanoparticles functionalized with either a cationic antibiotic drug, colistin, or a cationic poly(amidoamine) (PAMAM) dendrimer that is not an antibiotic drug. We show that both the colistin/hydrophobic Janus nanoparticles and dendrimer/hydrophobic Janus nanoparticles effectively inhibit the growth of both Gram-negative and Gram-positive bacteria at picomolar concentrations. The half-maximum effective concentrations (EC50) of those cationic/hydrophobic Janus nanoparticles against a variety of bacteria are in the picomolar range and significantly lower than those of conventional nanoparticles with uniform surface chemistry. The Janus nanoparticles inhibit bacterial growth by disrupting bacterial membranes and by inducing reactive oxygen species (ROS). Our results demonstrate that the design of the segregated hydrophobic and cationic charges on the nanoparticle surface is key for their antibiotic potency. The antibiotic potency of the Janus nanoparticles is applicable to cationic ligands and not limited to cationic antibiotic molecules. Those anisotropic amphiphilic Janus nanoparticles are promising new broad-spectrum antibiotic nanoparticles.

Download or read book Modeling of Interactions Between Nanoparticles and Cell Membranes written by Young-Min Ban and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The hydrophobic interaction between the particles and membrane core induces the strong coupling between the nanoparticle motion and membrane deformation. It is observed that the considered nanoparticles affect several physical properties of the membrane. The nanoparticles embedded into the membrane interior lead to the membrane softening, which becomes more significant with increase in CNT length and concentration. The lateral pressure profile and membrane energy in the membrane containing the nanoparticles exhibit localized perturbation around the nanoparticle. The nanoparticles are not likely to affect membrane protein function by the weak perturbation of the internal stress in the membrane. Due to the short-ranged interactions between the nanoparticles, the nanoparticles would not form aggregates inside membranes. The effect of lipid peroxidation on cell membrane deformation is assessed. The peroxidized lipids introduce a perturbation to the internal structure of the membrane leading to higher amplitude of the membrane fluctuations. Higher concentration of the peroxidized lipids induces more significant perturbation. Cumulative effects of lipid peroxidation caused by nanoparticles are examined for the first time. The considered amphiphilic particle appears to reduce the perturbation of the membrane structure at its equilibrium position inside the peroxidized membrane. This suggests a possibility of antioxidant effect of the nanoparticle.

Download or read book Advances in Biomembranes and Lipid Self Assembly written by and published by Elsevier. This book was released on 2023-12-01 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Biomembranes and Lipid Self-Assembly, Volume 38 in this updated series, highlights new advances in the field, with this new volume presenting interesting chapters on Interaction of inorganic debris particles with cells, Interactions between biomembrane embedded nanoparticles mediated by lipid bilayer, Topological defect driven nanoparticle assemblies, and more. - Provides the authority and expertise of leading contributors from an international board of authors - Presents the latest release in Advances in Biomembranes and Lipid Self-Assembly - Updated release includes the latest information on the Interaction of inorganic debris particles with cells, Interactions between biomembrane embedded nanoparticles mediated by lipid bilayer, and more

Download or read book Molecular Dynamics Simulation Studies of Interaction of Amphiphilic Molecules with Lipid Bilayers written by Jieqiong Lin and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Membrane Organization and Dynamics written by Amitabha Chattopadhyay and published by Springer. This book was released on 2017-12-06 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings together information on membrane organization and dynamics from a variety of spectroscopic, microscopic and simulation approaches, spanning a broad range of time scales. The implication of such dynamic information on membrane function in health and disease is a topic of contemporary interest. The chapters cover various aspects of membrane lipid and protein dynamics, explored using a battery of experimental and theoretical approaches. The synthesis of information and knowledge gained by utilizing multiple approaches will provide the reader with a comprehensive understanding of the underlying membrane dynamics and function, which will help to develop robust dynamic models for the understanding of membrane function in healthy and diseased states. In the last few years, crystal structures of an impressive number of membrane proteins have been reported, thanks to tremendous advances in membrane protein crystallization techniques. Some of these recently solved structures belong to the G protein-coupled receptor (GPCR) family, which are particularly difficult to crystallize due to their intrinsic flexibility. Nonetheless, these static structures do not provide the necessary information to understand the function of membrane proteins in the complex membrane milieu. This volume will address the dynamic nature of membrane proteins within the membrane and will provide the reader with an up-to date overview of the theory and practical approaches that can be used. This volume will be invaluable to researchers working in a wide range of scientific areas, from biochemistry and molecular biology to biophysics and protein science. Students of these fields will also find this volume very useful. This book will also be of great use to those who are interested in the dynamic nature of biological processes.

Download or read book Peptide Lipid Interactions written by Sidney A. Simon and published by Academic Press. This book was released on 2002-11-13 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains a comprehensive overview of peptide-lipid interactions by leading researchers. The first part covers theoretical concepts, experimental considerations, and thermodynamics. The second part presents new results obtained through site-directed EPR, electron microscopy, NMR, isothermal calorimetry, and fluorescence quenching. The final part covers problems of biological interest, including signal transduction, membrane transport, fusion, and adhesion. Key Features * world-renowned experts * state-of-the-art experimental methods * monolayers, bilayers, biological membranes * theoretical aspects and computer simulations * rafts * synaptic transmission * membrane fusion * signal transduction

Download or read book Interactions Between Nanospheres and Lipid Membranes written by Sudhir Upreti and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Potential applications of nanoparticles in various field including medicine and industries demand careful investigations of the interaction between nanoparticles and the plasma membrane and the resulting effect this has on the structural, mechanical and thermal properties of the plasma membrane. Furthermore, understanding the interactions between nanoparticles and bio membranes will allow us to design nanoparticles for optimal transmembrane transport. Using large-scaleLangevin molecular dynamics simulations, we systematically investigated the adsorption of spherical nanoparticles on lipid membranes, their effect on the morphological changes of the membrane, and the clustering of the nanoparticles. Our study is performed with changing the parameters such as the diameter of the nanoparticle, the strength of their interaction with the biomembrane and the surface coverage of the nanoparticles. We observed endocytosis in the membrane for single spherical nanoparticle at high interaction potential and small radius and relatively low interaction potential and high radius. Our results also indicate that for high nanoparticle density and for strong adsorption interactions the nanoparticles can lead to membrane lysis. However, for moderate adsorption interaction, the nanoparticles form long-lived linear clusters that are due to an effective curvature-driven attraction between the nanoparticles.

Download or read book Studies of Interactions of Amphiphilic Solutes with Lipid Bilayers written by Adriana S̆turcová and published by . This book was released on 2000 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interaction Between Nanoparticles and Aggregates of Amphiphile Molecules written by Falin Tian and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amphiphile molecules, endowed with a particular structure containing a hydrophilic head and a hydrophobic tail, have many important applications, e.g., fabrication of detergents, surface coating or surface functionalization, etc. Molecular aggregates of various forms, micelles, vehicle, membranes, etc. can be formed from amphiphile molecules. The complexity of these molecular aggregates involving a large number of atoms make the theoretical study of these system very challenging. Up to now, our understanding of the interaction between nanoparticles and aggregates of amphiphiles remains quite incomplete. Using a variety of molecular simulation methods and some theoretical approaches (Helfrich theory and perturbation theory), we have studied the following issues in the present thesis: 1. How the presence of nanoparticles, especially due to their highly curved surfaces, affects the aggregation of the amphiphiles? 2. How a lipid bilayer, a particular amphiphile aggregate, induces the self-assembly of hydrophobic nanoparticles.3. How the morphology transition of a membrane nanotube can be induced by nanoparticles?

Download or read book Advances in Planar Lipid Bilayers and Liposomes written by Ales Iglic and published by Academic Press. This book was released on 2012-09-04 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Planar Lipid Bilayers and Liposomes volumes cover a broad range of topics, including main arrangements of the reconstituted system, namely planar lipid bilayers as well as spherical liposomes. The invited authors present the latest results of their own research groups in this exciting multidisciplinary field. Incorporates contributions from newcomers and established and experienced researchers Explores the planar lipid bilayer systems and spherical liposomes from both theoretical and experimental perspectives Serves as an indispensable source of information for new scientists

Download or read book Nanocosmetics written by Jean Cornier and published by Springer. This book was released on 2019-06-14 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the application of nanotechnology to cosmetics. Edited by three respected experts in the field, the book begins with a general overview of the science behind cosmetics and skin care today, and of the status quo of nanotechnology in cosmetics. Subsequent chapters provide detailed information on the different nanoparticles currently used in cosmetics; the production and characterization of nanoparticles and nanocosmetics; and regulatory, safety and commercialization aspects. Given its scope, the book offers an indispensable guide for scientists in academia and industry, technicians and students, as well as a useful resource for decision-makers in the field and consumer organizations. Chapter 6 of this book is available open access under a CC BY 4.0 licence at link.springer.com.

Download or read book Physics of Biological Membranes written by Patricia Bassereau and published by Springer. This book was released on 2018-12-30 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book mainly focuses on key aspects of biomembranes that have emerged over the past 15 years. It covers static and dynamic descriptions, as well as modeling for membrane organization and shape at the local and global (at the cell level) scale. It also discusses several new developments in non-equilibrium aspects that have not yet been covered elsewhere. Biological membranes are the seat of interactions between cells and the rest of the world, and internally, they are at the core of complex dynamic reorganizations and chemical reactions. Despite the long tradition of membrane research in biophysics, the physics of cell membranes as well as of biomimetic or synthetic membranes is a rapidly developing field. Though successful books have already been published on this topic over the past decades, none include the most recent advances. Additionally, in this domain, the traditional distinction between biological and physical approaches tends to blur. This book gathers the most recent advances in this area, and will benefit biologists and physicists alike.

Download or read book Polymer Nanoparticles for Nanomedicines written by Christine Vauthier and published by Springer. This book was released on 2017-01-07 with total page 649 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume serves as a valuable handbook for the development of nanomedicines made of polymer nanoparticles because it provides researchers, students, and entrepreneurs with all the material necessary to begin their own projects in this field. Readers will find protocols to prepare polymer nanoparticles using different methods, since these are based on the variety of experiences that experts encounter in the field. In addition, complex topics such as, the optimal characterization of polymer nanoparticles is discussed, as well as practical guidelines on how to formulate polymer nanoparticles into nanomedicines, and how to modify the properties of nanoparticles to give them the different functionalities required to become an efficient nanomedicine for different clinical applications. The book also discusses the translation of technology from research to practice, considering aspects related to industrialization of preparation and aspects of regulatory and clinical development.

Download or read book Nanocarrier Technologies written by M. Reza Mozafari and published by Springer Science & Business Media. This book was released on 2006-09-24 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Designed as an advanced survey of the field, this book describes the key research parameters of nanocarrier technologies. It is the first book with this topic. It comprises a collection of scientific articles from top research people in the field and provides an up-to-date source containing recent citation and bibliography. The book is an indispensable source of information for new researchers and scientists.

Download or read book The Giant Vesicle Book written by Rumiana Dimova and published by CRC Press. This book was released on 2019-11-19 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Giant vesicles are widely used as a model membrane system, both for basic biological systems and for their promising applications in the development of smart materials and cell mimetics, as well as in driving new technologies in synthetic biology and for the cosmetics and pharmaceutical industry. The reader is guided to use giant vesicles, from the formation of simple membrane platforms to advanced membrane and cell system models. It also includes fundamentals for understanding lipid or polymer membrane structure, properties and behavior. Every chapter includes ideas for further applications and discussions on the implications of the observed phenomena towards understanding membrane-related processes. The Giant Vesicle Book is meant to be a road companion, a trusted guide for those making their first steps in this field as well as a source of information required by experts. Key Features • A complete summary of the field, covering fundamental concepts, practical methods, core theory, and the most promising applications • A start-up package of theoretical and experimental information for newcomers in the field • Extensive protocols for establishing the required preparations and assays • Tips and instructions for carefully performing and interpreting measurements with giant vesicles or for observing them, including pitfalls • Approaches developed for investigating giant vesicles as well as brief overviews of previous studies implementing the described techniques • Handy tables with data and structures for ready reference