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Aliakbarinodehi N, Niederkofler S, Emilsson G, Parkkila P, Olsén E, Jing Y, Sjöberg M, Agnarsson B, Lindfors L, Höök F. Time-Resolved Inspection of Ionizable Lipid-Facilitated Lipid Nanoparticle Disintegration and Cargo Release at an Early Endosomal Membrane Mimic. ACS NANO 2024; 18:22989-23000. [PMID: 39133894 PMCID: PMC11363135 DOI: 10.1021/acsnano.4c04519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 07/26/2024] [Accepted: 07/30/2024] [Indexed: 08/28/2024]
Abstract
Advances in lipid nanoparticle (LNP) design have contributed notably to the emergence of the current clinically approved mRNA-based vaccines and are of high relevance for delivering mRNA to combat diseases where therapeutic alternatives are sparse. LNP-assisted mRNA delivery utilizes ionizable lipid-mediated cargo translocation across the endosomal membrane driven by the acidification of the endosomal environment. However, this process occurs at a low efficiency, a few percent at the best. Utilizing surface-sensitive fluorescence microscopy with a single LNP and mRNA resolution, we have investigated pH-controlled interactions between individual LNPs and a planar anionic supported lipid bilayer (SLB) formed on nanoporous silica, mimicking the electrostatic conditions of the early endosomal membrane. For LNPs with an average diameter of 140 nm, fusion with the anionic SLB preferentially occurred when the pH was reduced from 6.6 to 6.0. Furthermore, there was a delay in the onset of LNP fusion after the pH drop, and upon fusion, a significant fraction (>70%) of mRNA was released into the acidic solution representing the endosomal lumen, while a fraction of mRNA remained bound to the SLB even after reversing the pH to neutral cytosolic conditions. Finally, a comparison of the fusion efficiency of two LNP formulations with different surface concentrations of gel-forming lipids correlated with differences in the protein translation efficiency previously observed in human primary cell transfection studies. Together, these findings emphasize the relevance of biophysical investigations of ionizable lipid-containing LNP-assisted mRNA delivery mechanisms while potentially also offering means to optimize the design of LNPs with enhanced endosomal escape capabilities.
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Affiliation(s)
- Nima Aliakbarinodehi
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Simon Niederkofler
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Gustav Emilsson
- Advanced
Drug Delivery, Pharmaceutical Sciences, AstraZeneca R&D, Mölndal 43181, Sweden
| | - Petteri Parkkila
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Erik Olsén
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Yujia Jing
- Advanced
Drug Delivery, Pharmaceutical Sciences, AstraZeneca R&D, Mölndal 43181, Sweden
| | - Mattias Sjöberg
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Björn Agnarsson
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Lennart Lindfors
- Advanced
Drug Delivery, Pharmaceutical Sciences, AstraZeneca R&D, Mölndal 43181, Sweden
| | - Fredrik Höök
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
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2
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Sun Y, Zang X, Sun Y, Wang L, Gao Z. Lipid membranes supported by planar porous substrates. Chem Phys Lipids 2020; 228:104893. [PMID: 32097619 DOI: 10.1016/j.chemphyslip.2020.104893] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/10/2020] [Indexed: 12/18/2022]
Abstract
Biological membranes play key roles in cell life, but their intrinsic complexity motivated the study and development of artificial lipid membranes with the primary aim to reconstitute and understand the natural functions in vitro. Porous-supported lipid membrane (pSLM) has emerged as a flexible platform for studying the surface chemistry of the cell due to their high stability and fluidity, and their ability to study the transmembrane process of the molecules. In this review, the pSLM, for the first time, to our knowledge, was divided into three types according to the way of the porous materials support the lipid membrane, containing the lipid membrane on the pores of the porous materials, the lipid membrane on both sides of the porous materials, the lipid membrane in the pores of the porous materials. All of these pSLMs were systematically elaborated from several aspects, including the substrates, formation, and characterization. Meanwhile, the advantages and disadvantages of each model membranes were summarized. Finally, suggestions for selecting appropriate pSLM and future directions in this area are discussed.
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Affiliation(s)
- Yanping Sun
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, 050018, China; State Key Laboratory Breeding Base - Hebei Province Key Laboratory of Molecular Chemistry for Drugs, Hebei University of Science and Technology, Shijiazhuang, 050018, China; Hebei Research Center of Pharmaceutical and Chemical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018, China
| | - Xianghuan Zang
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, 050018, China
| | - Yongjun Sun
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, 050018, China; Hebei Research Center of Pharmaceutical and Chemical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018, China
| | - Long Wang
- State Key Laboratory Breeding Base - Hebei Province Key Laboratory of Molecular Chemistry for Drugs, Hebei University of Science and Technology, Shijiazhuang, 050018, China; Department of Family and Consumer Sciences, California State University, Long Beach, CA, 90840, USA.
| | - Zibin Gao
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, 050018, China; State Key Laboratory Breeding Base - Hebei Province Key Laboratory of Molecular Chemistry for Drugs, Hebei University of Science and Technology, Shijiazhuang, 050018, China; Hebei Research Center of Pharmaceutical and Chemical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018, China.
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3
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Zhou S, Schlipf DM, Guilfoil EC, Rankin SE, Knutson BL. Lipid Pore-Filled Silica Thin-Film Membranes for Biomimetic Recovery of Dilute Carbohydrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14156-14166. [PMID: 29131638 DOI: 10.1021/acs.langmuir.7b03844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Selectively permeable biological membranes containing lipophilic barriers inspire the design of biomimetic carrier-mediated membranes for aqueous solute separation. The recovery of glucose, which can reversibly bind to boronic acid (BA) carriers, is examined in lipid pore-filled silica thin-film composite membranes with accessible mesopores. The successful incorporation of lipids (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) and BA carriers (4-((N-Boc-amino)methyl)phenylboronic acid, BAMP-BA) in the pores of mesoporous silica (∼10 nm pore diameter) through evaporation deposition is verified by confocal microscopy and differential scanning calorimetry. In the absence of BA carriers, lipids confined inside the pores of silica thin films (∼200 nm thick) provide a factor of 14 increase in diffusive transport resistance to glucose, relative to traditional supported lipid bilayers formed by vesicle fusion on the porous surface. The addition of lipid-immobilized BAMP-BA (59 mol % in DPPC) facilitates the transport of glucose through the membrane; glucose flux increases from 45 × 10-8 to 225 × 10-8 mol/m2/s in the presence of BAMP-BA. Furthermore, the transport can be improved by environmental factors including pH gradient (to control the binding and release of glucose) and temperature (to adjust lipid bilayer fluidity). The successful development of biomimetic nanocomposite membranes demonstrated here is an important step toward the efficient dilute aqueous solute upgrading or separations, such as the processing of carbohydrates from lignocellulose hydrolysates, using engineered carrier/catalyst/support systems.
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Affiliation(s)
- Shanshan Zhou
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Daniel M Schlipf
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Emma C Guilfoil
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Stephen E Rankin
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Barbara L Knutson
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
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4
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Teske N, Sibold J, Schumacher J, Teiwes NK, Gleisner M, Mey I, Steinem C. Continuous Pore-Spanning Lipid Bilayers on Silicon Oxide-Coated Porous Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14175-14183. [PMID: 29148811 DOI: 10.1021/acs.langmuir.7b02727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A number of techniques has been developed and analyzed in recent years to generate pore-spanning membranes (PSMs). While quite a number of methods rely on nanoporous substrates, only a few use micrometer-sized pores to be able to individually resolve suspending membranes by means of fluorescence microscopy. To be able to produce PSMs on pores that are micrometer in size, an orthogonal functionalization strategy resulting in a hydrophilic surface is highly desirable. Here, we report on a method to prepare PSMs based on the evaporation of a thin layer of silicon monoxide on top of the porous substrate. PM-IRRAS experiments demonstrate that the final surface is composed of SiOx with 1 < x < 2. The hydrophilic surface turned out to be well suited to spread giant unilamellar vesicles forming PSMs. As the method does not rely on a gold coating as frequently used for orthogonal functionalization, fluorescence micrographs provide information not only from the freestanding membrane areas but also from the supported ones. The observation of the entire PSM area enabled us to observe phase-separation in these membranes on the freestanding and supported parts as well as protein binding and possible lipid reorganization of the membranes induced by binding of the protein Shiga toxin.
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Affiliation(s)
- Nelli Teske
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstraße 2, 37077 Göttingen, Germany
| | - Jeremias Sibold
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstraße 2, 37077 Göttingen, Germany
| | - Johannes Schumacher
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstraße 2, 37077 Göttingen, Germany
| | - Nikolas K Teiwes
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstraße 2, 37077 Göttingen, Germany
| | - Martin Gleisner
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstraße 2, 37077 Göttingen, Germany
| | - Ingo Mey
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstraße 2, 37077 Göttingen, Germany
| | - Claudia Steinem
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstraße 2, 37077 Göttingen, Germany
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5
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Malekkhaiat Häffner S, Malmsten M. Membrane interactions and antimicrobial effects of inorganic nanoparticles. Adv Colloid Interface Sci 2017; 248:105-128. [PMID: 28807368 DOI: 10.1016/j.cis.2017.07.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/20/2017] [Accepted: 07/25/2017] [Indexed: 12/19/2022]
Abstract
Interactions between nanoparticles and biological membranes are attracting increasing attention in current nanomedicine, and play a key role both for nanotoxicology and for utilizing nanomaterials in diagnostics, drug delivery, functional biomaterials, as well as combinations of these, e.g., in theranostics. In addition, there is considerable current interest in the use of nanomaterials as antimicrobial agents, motivated by increasing resistance development against conventional antibiotics. Here, various nanomaterials offer opportunities for triggered functionalites to combat challenging infections. Although the performance in these diverse applications is governed by a complex interplay between the nanomaterial, the properties of included drugs (if any), and the biological system, nanoparticle-membrane interactions constitute a key initial step and play a key role for the subsequent biological response. In the present overview, the current understanding of inorganic nanomaterials as antimicrobial agents is outlined, with special focus on the interplay between antimicrobial effects and membrane interactions, and how membrane interactions and antimicrobial effects of such materials depend on nanoparticle properties, membrane composition, and external (e.g., light and magnetic) fields.
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Affiliation(s)
| | - Martin Malmsten
- Department of Pharmacy, University of Copenhagen, DK-2100 Copenhagen, Denmark; Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden.
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6
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Isaksson S, Watkins EB, Browning KL, Kjellerup Lind T, Cárdenas M, Hedfalk K, Höök F, Andersson M. Protein-Containing Lipid Bilayers Intercalated with Size-Matched Mesoporous Silica Thin Films. NANO LETTERS 2017; 17:476-485. [PMID: 28073257 DOI: 10.1021/acs.nanolett.6b04493] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Proteins are key components in a multitude of biological processes, of which the functions carried out by transmembrane (membrane-spanning) proteins are especially demanding for investigations. This is because this class of protein needs to be incorporated into a lipid bilayer representing its native environment, and in addition, many experimental conditions also require a solid support for stabilization and analytical purposes. The solid support substrate may, however, limit the protein functionality due to protein-material interactions and a lack of physical space. We have in this work tailored the pore size and pore ordering of a mesoporous silica thin film to match the native cell-membrane arrangement of the transmembrane protein human aquaporin 4 (hAQP4). Using neutron reflectivity (NR), we provide evidence of how substrate pores host the bulky water-soluble domain of hAQP4, which is shown to extend 7.2 nm into the pores of the substrate. Complementary surface analytical tools, including quartz crystal microbalance with dissipation monitoring (QCM-D) and fluorescence microscopy, revealed successful protein-containing supported lipid bilayer (pSLB) formation on mesoporous silica substrates, whereas pSLB formation was hampered on nonporous silica. Additionally, electron microscopy (TEM and SEM), light scattering (DLS and stopped-flow), and small-angle X-ray scattering (SAXS) were employed to provide a comprehensive characterization of this novel hybrid organic-inorganic interface, the tailoring of which is likely to be generally applicable to improve the function and stability of a broad range of membrane proteins containing water-soluble domains.
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Affiliation(s)
- Simon Isaksson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology , SE-41296 Gothenburg, Sweden
| | - Erik B Watkins
- Materials Physics and Application Division, MPA-11, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | | | - Tania Kjellerup Lind
- Department of Biomedical Sciences and Biofilm-The Research Center for Biointerfaces, Health & Society, Malmo University , SE-20500 Malmo, Sweden
| | - Marité Cárdenas
- Department of Biomedical Sciences and Biofilm-The Research Center for Biointerfaces, Health & Society, Malmo University , SE-20500 Malmo, Sweden
| | - Kristina Hedfalk
- Department of Chemistry and Molecular Biology, University of Gothenburg , SE-40530 Gothenburg, Sweden
| | - Fredrik Höök
- Department of Applied Physics, Chalmers University of Technology , SE-41296 Gothenburg, Sweden
| | - Martin Andersson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology , SE-41296 Gothenburg, Sweden
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7
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Karlsson J, Harmankaya N, Palmquist A, Atefyekta S, Omar O, Tengvall P, Andersson M. Stem cell homing using local delivery of plerixafor and stromal derived growth factor-1alpha for improved bone regeneration around Ti-implants. J Biomed Mater Res A 2016; 104:2466-75. [DOI: 10.1002/jbm.a.35786] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/16/2016] [Accepted: 05/18/2016] [Indexed: 01/14/2023]
Affiliation(s)
- Johan Karlsson
- Department Of Chemistry and Chemical Engineering; Applied Chemistry, Chalmers University of Technology; Gothenburg Sweden
| | - Necati Harmankaya
- Department Of Fibre and Polymer Technology; KTH Royal Institute of Technology; Stockholm Sweden
| | - Anders Palmquist
- Department Of Biomaterials; Sahlgrenska Academy, University of Gothenburg; Gothenburg Sweden
| | - Saba Atefyekta
- Department Of Chemistry and Chemical Engineering; Applied Chemistry, Chalmers University of Technology; Gothenburg Sweden
| | - Omar Omar
- Department Of Biomaterials; Sahlgrenska Academy, University of Gothenburg; Gothenburg Sweden
| | - Pentti Tengvall
- Department Of Biomaterials; Sahlgrenska Academy, University of Gothenburg; Gothenburg Sweden
| | - Martin Andersson
- Department Of Chemistry and Chemical Engineering; Applied Chemistry, Chalmers University of Technology; Gothenburg Sweden
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8
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Wallin M, Choi JH, Kim SO, Cho NJ, Andersson M. Peptide-induced formation of a tethered lipid bilayer membrane on mesoporous silica. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 44:27-36. [DOI: 10.1007/s00249-014-0998-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/20/2014] [Accepted: 10/29/2014] [Indexed: 11/29/2022]
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9
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Wang CY, Hill RJ. Transmembrane protein diffusion in gel-supported dual-leaflet membranes. Biophys J 2014; 107:2296-304. [PMID: 25418298 DOI: 10.1016/j.bpj.2014.10.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/09/2014] [Accepted: 10/15/2014] [Indexed: 10/24/2022] Open
Abstract
Tools to measure transmembrane-protein diffusion in lipid bilayer membranes have advanced in recent decades, providing a need for predictive theoretical models that account for interleaflet leaflet friction on tracer mobility. Here we address the fully three-dimensional flows driven by a (nonprotruding) transmembrane protein embedded in a dual-leaflet membrane that is supported above and below by soft porous supports (e.g., hydrogel or extracellular matrix), each of which has a prescribed permeability and solvent viscosity. For asymmetric configurations, i.e., supports with contrasting permeability, as realized for cells in contact with hydrogel scaffolds or culture media, the diffusion coefficient can reflect interleaflet friction. Reasonable approximations, for sufficiently large tracers on low-permeability supports, are furnished by a recent phenomenological theory from the literature. Interpreting literature data, albeit for hard-supported membranes, provides a theoretical basis for the phenomenological Stokes drag law as well as strengthening assertions that nonhydrodynamic interactions are important in supported bilayer systems, possibly leading to overestimates of the membrane/leaflet viscosity. Our theory provides a theoretical foundation for future experimental studies of tracer diffusion in gel-supported membranes.
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Affiliation(s)
- Chih-Ying Wang
- Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada
| | - Reghan J Hill
- Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada.
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10
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Peng PY, Chiang PC, Chao L. Controllable occurrence of free-standing lipid membranes on nanograting structured supports. ACS APPLIED MATERIALS & INTERFACES 2014; 6:12261-12269. [PMID: 24988277 DOI: 10.1021/am501861a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Supported lipid bilayers (SLBs) have been widely used to study protein-lipid membrane interactions because their planar geometry is suitable for many surface analysis tools. However, the friction coupling between the support and the membrane can influence the properties of biomolecules in the membrane. Many studies have attempted to span SLBs over nanostructured supports to create free-standing regions in SLBs for biosensor applications. However, membranes following the support surface contour are more frequently observed than are free-standing membranes on structured supports, indicating that the parameter range suitable for formation of free-standing SLBs might be narrow and more information is necessary to understand the required conditions. The objective of this study was to estimate the system energies of free-standing and contour-following membrane states and determine which state is the most energetically favorable under various conditions. For a lipid membrane preferring to stay close to the support, an energy reward occurs when they are in close proximity; however, increasing the contact area on a structured surface can result in an energy penalty because of the bending of the lipid bilayer. Whether the energy reward or the energy penalty dominates could determine the membrane state. We used the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and the Helfrich bending theory to relate the energy sizes to experimentally controllable parameters. We experimentally examined whether the membrane state followed the model prediction when we used various buffer ionic strengths, various lipid types, and nanograting supports with three different geometries. Because it is difficult to observe the experimental membrane state directly at the nanoscale, we developed a method to use the fluorescence recovery shape change after photobleaching to distinguish experimental membrane states at the micrometer scale. Our experimental results closely matched the theoretical predictions, suggesting that the developed model can be used to predict suitable conditions for formation of free-standing bilayers on nanostructured solid supports.
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Affiliation(s)
- Po-Yu Peng
- Department of Chemical Engineering, National Taiwan University , Taipei 106, Taiwan
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11
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Jadidi T, Seyyed-Allaei H, Tabar MRR, Mashaghi A. Poisson's Ratio and Young's Modulus of Lipid Bilayers in Different Phases. Front Bioeng Biotechnol 2014; 2:8. [PMID: 25152882 PMCID: PMC4126470 DOI: 10.3389/fbioe.2014.00008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 04/04/2014] [Indexed: 11/18/2022] Open
Abstract
A general computational method is introduced to estimate the Poisson's ratio for membranes with small thickness. In this method, the Poisson's ratio is calculated by utilizing a rescaling of inter-particle distances in one lateral direction under periodic boundary conditions. As an example for the coarse grained lipid model introduced by Lenz and Schmid, we calculate the Poisson's ratio in the gel, fluid, and interdigitated phases. Having the Poisson's ratio, enable us to obtain the Young's modulus for the membranes in different phases. The approach may be applied to other membranes such as graphene and tethered membranes in order to predict the temperature dependence of its Poisson's ratio and Young's modulus.
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Affiliation(s)
- Tayebeh Jadidi
- Department of Physics, University of Osnabrück, Osnabrück, Germany
| | | | - M. Reza Rahimi Tabar
- Department of Physics, Sharif University of Technology, Tehran, Iran
- Institute of Physics, Carl-von-Ossietzky University, Oldenburg, Germany
| | - Alireza Mashaghi
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands
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12
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Khan MS, Dosoky NS, Williams JD. Engineering lipid bilayer membranes for protein studies. Int J Mol Sci 2013; 14:21561-97. [PMID: 24185908 PMCID: PMC3856022 DOI: 10.3390/ijms141121561] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 10/13/2013] [Accepted: 10/21/2013] [Indexed: 01/05/2023] Open
Abstract
Lipid membranes regulate the flow of nutrients and communication signaling between cells and protect the sub-cellular structures. Recent attempts to fabricate artificial systems using nanostructures that mimic the physiological properties of natural lipid bilayer membranes (LBM) fused with transmembrane proteins have helped demonstrate the importance of temperature, pH, ionic strength, adsorption behavior, conformational reorientation and surface density in cellular membranes which all affect the incorporation of proteins on solid surfaces. Much of this work is performed on artificial templates made of polymer sponges or porous materials based on alumina, mica, and porous silicon (PSi) surfaces. For example, porous silicon materials have high biocompatibility, biodegradability, and photoluminescence, which allow them to be used both as a support structure for lipid bilayers or a template to measure the electrochemical functionality of living cells grown over the surface as in vivo. The variety of these media, coupled with the complex physiological conditions present in living systems, warrant a summary and prospectus detailing which artificial systems provide the most promise for different biological conditions. This study summarizes the use of electrochemical impedance spectroscopy (EIS) data on artificial biological membranes that are closely matched with previously published biological systems using both black lipid membrane and patch clamp techniques.
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Affiliation(s)
- Muhammad Shuja Khan
- Electrical and Computer Engineering Department, University of Alabama in Huntsville, Huntsville, AL 35899, USA; E-Mail:
| | - Noura Sayed Dosoky
- Biological Sciences Department, University of Alabama in Huntsville, Huntsville, AL 35899, USA; E-Mail:
| | - John Dalton Williams
- Electrical and Computer Engineering Department, University of Alabama in Huntsville, Huntsville, AL 35899, USA; E-Mail:
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13
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Karlsson J, Jimbo R, Fathali HM, Schwartz-Filho HO, Hayashi M, Halvarsson M, Wennerberg A, Andersson M. In vivo biomechanical stability of osseointegrating mesoporous TiO(2) implants. Acta Biomater 2012; 8:4438-46. [PMID: 22842030 DOI: 10.1016/j.actbio.2012.07.035] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/17/2012] [Accepted: 07/20/2012] [Indexed: 11/28/2022]
Abstract
Mesoporous materials are of high interest as implant coatings to receive an enhanced osseointegration. In this study, titanium implants coated with mesoporous TiO(2) thin films have been evaluated both in vitro and in vivo. Material characterization showed that, with partly crystalline TiO(2) (anatase), long-range-ordered hydrophilic mesoporous thin films with a pore size of 6nm were obtained. Evaluation of the mechanical resistance showed that the films were robust enough to withstand the standard implantation procedure. In vitro apatite formation was studied using simulated body fluids, showing that the pores are accessible for ions and that formation of apatite was increased due to the presence of the mesopores. An in vivo study using a rabbit model was executed in which the removal torque and histomorphometry were evaluated. The results show that the biomechanical stability of the TiO(2) coating was unaffected by the presence of mesopores and that osseointegration was achieved without any signs of inflammation.
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Affiliation(s)
- Johan Karlsson
- Department of Chemical and Biological Engineering, Applied Chemistry, Chalmers University of Technology, Gothenburg, Sweden
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14
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Abstract
Lipid bilayers are natural barriers of biological cells and cellular compartments. Membrane proteins integrated in biological membranes enable vital cell functions such as signal transduction and the transport of ions or small molecules. In order to determine the activity of a protein of interest at defined conditions, the membrane protein has to be integrated into artificial lipid bilayers immobilized on a surface. For the fabrication of such biosensors expertise is required in material science, surface and analytical chemistry, molecular biology and biotechnology. Specifically, techniques are needed for structuring surfaces in the micro- and nanometer scale, chemical modification and analysis, lipid bilayer formation, protein expression, purification and solubilization, and most importantly, protein integration into engineered lipid bilayers. Electrochemical and optical methods are suitable to detect membrane activity-related signals. The importance of structural knowledge to understand membrane protein function is obvious. Presently only a few structures of membrane proteins are solved at atomic resolution. Functional assays together with known structures of individual membrane proteins will contribute to a better understanding of vital biological processes occurring at biological membranes. Such assays will be utilized in the discovery of drugs, since membrane proteins are major drug targets.
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