1
|
Thaden O, Schneider N, Walther T, Spiller E, Taoum A, Göpfrich K, Duarte Campos D. Bioprinting of Synthetic Cell-like Lipid Vesicles to Augment the Functionality of Tissues after Manufacturing. ACS Synth Biol 2024. [PMID: 39025476 DOI: 10.1021/acssynbio.4c00137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Bioprinting is an automated bioassembly method that enables the formation of human tissue-like constructs to restore or replace damaged tissues. Regardless of the employed bioprinting method, cells undergo mechanical stress that can impact their survival and function postprinting. In this study, we investigate the use of a synthetic cell-like unit, giant unilamellar vesicles (GUVs), as adjuvants of the cellular function of human cells postprinting, or in future as the complete replacement of human cells. We analyzed the impact of two nozzle-based bioprinting methods (drop-on-demand and extrusion bioprinting) on the structure, stability, and function of GUVs. We showed that over 65% of the GUVs remain intact when printing at 0.5 bar, demonstrating the potential of using GUVs as a synthetic cell source. We further increased the stability of GUVs in a cell culture medium by introducing polyethylene glycol (PEG) into the GUV lipid membrane. The presence of PEG, however, diminished the structural properties of GUVs postprinting, and reduced the interaction of GUVs with human cells. Although the design of PEG-GUVs can still be modified in future studies for better cell-GUV interactions, we demonstrated that GUVs are functional postprinting. Chlorin e6-PEG-GUVs loaded with a fluorescent dye were bioprinted, and they released the dye postprinting only upon illumination. This is a new strategy to deliver carriers, such as growth factors, drugs, nutrients, or gases, inside large bioprinted specimens on a millimeter to centimeter scale. Overall, we showed that printed GUVs can augment the functionality of manufactured human tissues.
Collapse
Affiliation(s)
- Ole Thaden
- Bioprinting & Tissue Engineering Group, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - Nicole Schneider
- Bioprinting & Tissue Engineering Group, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - Tobias Walther
- Biophysical Engineering of Life Group, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
- Max Planck Institute for Medical Research, Heidelberg 69120, Germany
| | - Erin Spiller
- Bioprinting & Tissue Engineering Group, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - Alexandre Taoum
- Bioprinting & Tissue Engineering Group, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - Kerstin Göpfrich
- Biophysical Engineering of Life Group, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
- Max Planck Institute for Medical Research, Heidelberg 69120, Germany
| | - Daniela Duarte Campos
- Bioprinting & Tissue Engineering Group, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| |
Collapse
|
2
|
Gye H, Baek H, Han S, Kwon H, Nguyen TVT, Pham LTM, Kang S, Nho YH, Lee DW, Kim YH. Recombinant Lignin Peroxidase with Superior Thermal Stability and Melanin Decolorization Efficiency in a Typical Human Skin-Mimicking Environment. Biomacromolecules 2023. [PMID: 37075205 DOI: 10.1021/acs.biomac.3c00123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
Recently, the desire for a safe and effective method for skin whitening has been growing in the cosmetics industry. Commonly used tyrosinase-inhibiting chemical reagents exhibit side effects. Thus, recent studies have focused on performing melanin decolorization with enzymes as an alternative due to the low toxicity of enzymes and their ability to decolorize melanin selectively. Herein, 10 different isozymes were expressed as recombinant lignin peroxidases (LiPs) from Phanerochaete chrysosporium (PcLiPs), and PcLiP isozyme 4 (PcLiP04) was selected due to its high stability and activity at pH 5.5 and 37 °C, which is close to human skin conditions. In vitro melanin decolorization results indicated that PcLiP04 exhibited at least 2.9-fold higher efficiency than that of well-known lignin peroxidase (PcLiP01) in a typical human skin-mimicking environment. The interaction force between melanin films measured by a surface forces apparatus (SFA) revealed that the decolorization of melanin by PcLiP04 harbors a disrupted structure, possibly interrupting π-π stacking and/or hydrogen bonds. In addition, a 3D reconstructed human pigmented epidermis skin model showed a decrease in melanin area to 59.8% using PcLiP04, which suggests that PcLiP04 exhibits a strong potential for skin whitening.
Collapse
Affiliation(s)
- Hyeryeong Gye
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Heeyeon Baek
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Seunghyun Han
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Haeun Kwon
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Trang Vu Thien Nguyen
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Le Thanh Mai Pham
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Seunghyun Kang
- Bio Technology Lab, COSMAX BTI R&I Center, Seongnam 13486, Republic of Korea
| | - Youn Hwa Nho
- Bio Technology Lab, COSMAX BTI R&I Center, Seongnam 13486, Republic of Korea
| | - Dong Woog Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Yong Hwan Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
- Graduate School of Carbon Neutrality, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST-gil, Ulsan 44919, Republic of Korea
| |
Collapse
|
3
|
Cao Y, Klein J. Lipids and lipid mixtures in boundary layers: From hydration lubrication to osteoarthritis. Curr Opin Colloid Interface Sci 2022. [DOI: 10.1016/j.cocis.2021.101559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
4
|
Porras-Gómez M, Shoaib T, Steer D, Espinosa-Marzal RM, Leal C. Pathological cardiolipin-promoted membrane hemifusion stiffens pulmonary surfactant membranes. Biophys J 2022; 121:886-896. [PMID: 35176270 PMCID: PMC8943818 DOI: 10.1016/j.bpj.2022.02.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/17/2022] [Accepted: 02/09/2022] [Indexed: 11/27/2022] Open
Abstract
Lower tract respiratory diseases such as pneumonia are pervasive, affecting millions of people every year. The stability of the air/water interface in alveoli and the mechanical performance during the breathing cycle are regulated by the structural and elastic properties of pulmonary surfactant membranes (PSMs). Respiratory dysfunctions and pathologies often result in, or are caused by, impairment of the PSMs. However, a gap remains between our knowledge of the etiology of lung diseases and the fundamental properties of PSMs. For example, bacterial pneumonia in humans and mice has been associated with aberrant levels of cardiolipin, a mitochondrial-specific, highly unsaturated 4-tailed anionic phospholipid, in lung fluid, which likely disrupts the structural and mechanical integrity of PSMs. Specifically, cardiolipin is expected to significantly alter PSM elasticity due to its intrinsic molecular properties favoring membrane folding away from a flat configuration. In this paper, we investigate the structural and mechanical properties of the lipidic components of PSMs using lipid-based models as well as bovine extracts affected by the addition of pathological cardiolipin levels. Specifically, using a combination of optical and atomic force microscopy with a surface force apparatus, we demonstrate that cardiolipin strongly promotes hemifusion of PSMs and that these local membrane contacts propagate at larger scales, resulting in global stiffening of lung membranes.
Collapse
Affiliation(s)
- Marilyn Porras-Gómez
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Tooba Shoaib
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Dylan Steer
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Rosa Maria Espinosa-Marzal
- Department of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Cecília Leal
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois.
| |
Collapse
|
5
|
Investigation of the domain line tension in asymmetric vesicles prepared via hemifusion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183586. [PMID: 33647248 DOI: 10.1016/j.bbamem.2021.183586] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/28/2021] [Accepted: 02/12/2021] [Indexed: 12/20/2022]
Abstract
The plasma membrane (PM) is asymmetric in lipid composition. The distinct and characteristic lipid compositions of the exoplasmic and cytoplasmic leaflets lead to different lipid-lipid interactions and physical-chemical properties in each leaflet. The exoplasmic leaflet possesses an intrinsic ability to form coexisting ordered and disordered fluid domains, whereas the cytoplasmic leaflet seems to form a single fluid phase. To better understand the interleaflet interactions that influence domains, we compared asymmetric model membranes that capture salient properties of the PM with simpler symmetric membranes. Using asymmetric giant unilamellar vesicles (aGUVs) prepared by hemifusion with a supported lipid bilayer, we investigate the domain line tension that characterizes the behavior of coexisting ordered + disordered domains. The line tension can be related to the contact perimeter of the different phases. Compared to macroscopic phase separation, the appearance of modulated phases was found to be a robust indicator of a decrease in domain line tension. Symmetric GUVs of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)/1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC)/cholesterol (chol) were formed into aGUVs by replacing the GUV outer leaflet with DOPC/chol = 0.8/0.2 in order to create a cytoplasmic leaflet model. These aGUVs revealed lower line tension for the ordered + disordered domains of the exoplasmic model leaflet.
Collapse
|
6
|
Kan Y, Yang Q, Tan Q, Wei Z, Chen Y. Diminishing Cohesion of Chitosan Films in Acidic Solution by Multivalent Metal Cations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4964-4974. [PMID: 32308004 DOI: 10.1021/acs.langmuir.0c00438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Chitosan is a natural polymer with good biocompatibility, biodegradability, and bioactivity that has great potential for biomedical and industrial applications. Like other natural sugar-based polymers, chitosan molecules own versatile adhesion abilities to bind with various surfaces, owing to multiple functional moieties contained in the chain. To develop the promising biomaterials based on the chitosan chemistry, it is fundamentally important to figure out its adhesion mechanism under a certain condition, which leaves us numbers of open questions. In this work, we characterized the chitosan films adsorbed on a mica substrate in acidic solution and investigated the effects of multivalent salts on the cohesive behaviors of the films by means of the surface forces apparatus. The results showed that the cohesion capacities of chitosan films were reduced to around 30% of their original states after the addition of 10-7 M LaCl3 into 150 mM acetic acid, which could be partially recovered by holding the films at the contact position for a longer time. Surprisingly, the cohesion loss in the films exhibited the dependence on the properties of the metal cations including valance and concentration. The topography of the chitosan-coated surface also showed obvious aggregation in the presence of submicromolar of the salts. Here, we attributed these phenomena regarding cohesion loss to the mechanisms involved in the absorption of metal cations by the chitosan chains, which not only consumed the binding sites but also induced conformation change in the polymer network. Our findings may offer a suggestion for the production of chitosan-based materials to notice the potential impacts of ultralow concentrated salts that are usually neglected even under acidic conditions.
Collapse
Affiliation(s)
- Yajing Kan
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, and School of Mechanical Engineering, Southeast University, Nanjing 211189, China
| | - Qiang Yang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, and School of Mechanical Engineering, Southeast University, Nanjing 211189, China
| | - Qiyan Tan
- School of Mechanical Engineering, Nanjing Institute of Technology, Nanjing 211167, China
| | - Zhiyong Wei
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, and School of Mechanical Engineering, Southeast University, Nanjing 211189, China
| | - Yunfei Chen
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, and School of Mechanical Engineering, Southeast University, Nanjing 211189, China
| |
Collapse
|
7
|
Kristiansen K, Donaldson SH, Berkson ZJ, Scott J, Su R, Banquy X, Lee DW, de Aguiar HB, McGraw JD, Degen GD, Israelachvili JN. Multimodal Miniature Surface Forces Apparatus (μSFA) for Interfacial Science Measurements. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15500-15514. [PMID: 31362502 DOI: 10.1021/acs.langmuir.9b01808] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Advances in the research of intermolecular and surface interactions result from the development of new and improved measurement techniques and combinations of existing techniques. Here, we present a new miniature version of the surface forces apparatus-the μSFA-that has been designed for ease of use and multimodal capabilities with the retention of the capabilities of other SFA models including accurate measurements of the surface separation distance and physical characterization of dynamic and static physical forces (i.e., normal, shear, and friction) and interactions (e.g., van der Waals, electrostatic, hydrophobic, steric, and biospecific). The small physical size of the μSFA, compared to previous SFA models, makes it portable and suitable for integration into commercially available optical and fluorescence light microscopes, as demonstrated here. The large optical path entry and exit ports make it ideal for concurrent force measurements and spectroscopy studies. Examples of the use of the μSFA in combination with surface plasmon resonance (SPR) and Raman spectroscopy measurements are presented. Because of the short working distance constraints associated with Raman spectroscopy, an interferometric technique was developed and applied to calculate the intersurface separation distance based on Newton's rings. The introduction of the μSFA will mark a transition in SFA usage from primarily physical characterization to concurrent physical characterization with in situ chemical and biological characterization to study interfacial phenomena, including (but not limited to) molecular adsorption, fluid flow dynamics, the determination of surface species and morphology, and (bio)molecular binding kinetics.
Collapse
Affiliation(s)
- Kai Kristiansen
- Department of Chemical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Stephen H Donaldson
- Département de Physique, Ecole Normale Supérieure/PSL , Research University , CNRS, 24 rue Lhomond , 75005 Paris , France
| | - Zachariah J Berkson
- Department of Chemical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Jeffrey Scott
- SurForce LLC , Goleta , California 93117 , United States
| | - Rongxin Su
- State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Xavier Banquy
- Faculty of Pharmacy , Université de Montréal , Succursale Centre Ville , Montréal , Quebec H3C 3J7 , Canada
| | - Dong Woog Lee
- School of Energy and Chemical Engineering , Ulsan National Institute of Science and Technology , Ulsan 44919 , Republic of Korea
| | - Hilton B de Aguiar
- Département de Physique, Ecole Normale Supérieure/PSL , Research University , CNRS, 24 rue Lhomond , 75005 Paris , France
| | - Joshua D McGraw
- Département de Physique, Ecole Normale Supérieure/PSL , Research University , CNRS, 24 rue Lhomond , 75005 Paris , France
- Gulliver CNRS UMR 7083 , PSL Research University, ESPCI Paris , 10 rue Vauquelin , 75005 Paris , France
| | - George D Degen
- Department of Chemical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Jacob N Israelachvili
- Department of Chemical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| |
Collapse
|
8
|
Enoki TA, Feigenson GW. Asymmetric Bilayers by Hemifusion: Method and Leaflet Behaviors. Biophys J 2019; 117:1037-1050. [PMID: 31493862 DOI: 10.1016/j.bpj.2019.07.054] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/13/2019] [Accepted: 07/08/2019] [Indexed: 01/03/2023] Open
Abstract
We describe a new method to prepare asymmetric giant unilamellar vesicles (aGUVs) via hemifusion. Hemifusion of giant unilamellar vesicles and a supported lipid bilayer, triggered by calcium, promotes the lipid exchange of the fused outer leaflets mediated by lipid diffusion. We used different fluorescent dyes to monitor the inner and the outer leaflets of the unsupported aGUVs. We confirmed that almost all newly exchanged lipids in the aGUVs are found in the outer leaflet of these asymmetric vesicles. In addition, we test the stability of the aGUVs formed by hemifusion in preserving their contents during the procedure. For aGUVs prepared from the hemifusion of giant unilamellar vesicles composed of 1,2-distearoyl-sn-glycero-3-phosphocholine/1,2-dioleoyl-sn-glycero-3-phosphocholine/cholesterol = 0.39/0.39/0.22 and a supported lipid bilayer of 1,2-dioleoyl-sn-glycero-3-phosphocholine/cholesterol = 0.8/0.2, we observed the exchanged lipids to alter the bilayer properties. To access the physical and chemical properties of the asymmetric bilayer, we monitored the dye partition coefficients of individual leaflets and the generalized polarization of the fluorescence probe 6-dodecanoyl-2-[ N-methyl-N-(carboxymethyl)amino] naphthalene, a sensor for the lipid packing/order of its surroundings. For a high percentage of lipid exchange (>70%), the dye partition indicates induced-disordered and induced-ordered domains. The induced domains have distinct lipid packing/order compared to the symmetric liquid-disordered and liquid-ordered domains.
Collapse
Affiliation(s)
- Thais A Enoki
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York.
| | - Gerald W Feigenson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
| |
Collapse
|
9
|
Lee DW. Revisiting the Interaction Force Measurement between Lipid Bilayers Using a Surface Forces Apparatus (SFA). J Oleo Sci 2018; 67:1361-1372. [PMID: 30404956 DOI: 10.5650/jos.ess18088] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Dong Woog Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology
| |
Collapse
|
10
|
Lipid Order Degradation in Autoimmune Demyelination Probed by Polarized Coherent Raman Microscopy. Biophys J 2017; 113:1520-1530. [PMID: 28978445 DOI: 10.1016/j.bpj.2017.07.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/23/2017] [Accepted: 07/26/2017] [Indexed: 01/15/2023] Open
Abstract
Myelin around axons is currently widely studied by structural analyses and large-scale imaging techniques, with the goal to decipher its critical role in neuronal protection. Although there is strong evidence that in myelin, lipid composition, and lipid membrane morphology are affected during the progression of neurodegenerative diseases, there is no quantitative method yet to report its ultrastructure in tissues at both molecular and macroscopic levels, in conditions potentially compatible with in vivo observations. In this work, we study and quantify the molecular order of lipids in myelin at subdiffraction scales, using label-free polarization-resolved coherent anti-Stokes Raman, which exploits coherent anti-Stokes Raman sensitivity to coupling between light polarization and oriented molecular vibrational bonds. Importantly, the method does not use any a priori parameters in the sample such as lipid type, orientational organization, and composition. We show that lipid molecular order of myelin in the mouse spinal cord is significantly reduced throughout the progression of experimental autoimmune encephalomyelitis, a model for multiple sclerosis, even in myelin regions that appear morphologically unaffected. This technique permits us to unravel molecular-scale perturbations of lipid layers at an early stage of the demyelination progression, whereas the membrane architecture at the mesoscopic scale (here ∼100 nm) seems much less affected. Such information cannot be brought by pure morphological observation and, to our knowledge, brings a new perspective to molecular-scale understanding of neurodegenerative diseases.
Collapse
|
11
|
Rougon G, Brasselet S, Debarbieux F. Advances in Intravital Non-Linear Optical Imaging of the Central Nervous System in Rodents. Brain Plast 2016; 2:31-48. [PMID: 29765847 PMCID: PMC5928564 DOI: 10.3233/bpl-160028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose of review: Highly coordinated cellular interactions occur in the healthy or pathologic adult rodent central nervous system (CNS). Until recently, technical challenges have restricted the analysis of these events to largely static modes of study such as immuno-fluorescence and electron microscopy on fixed tissues. The development of intravital imaging with subcellular resolution is required to probe the dynamics of these events in their natural context, the living brain. Recent findings: This review focuses on the recently developed live non-linear optical imaging modalities, the core principles involved, the identified technical challenges that limit their use and the scope of their applications. We highlight some practical applications for these modalities with a specific attention given to Experimental Autoimmune Encephalomyelitis (EAE), a rodent model of a chronic inflammatory disease of the CNS characterized by the formation of disseminated demyelinating lesions accompanied by axonal degeneration. Summary: We conclude that label-free nonlinear optical imaging combined to two photon imaging will continue to contribute richly to comprehend brain function and pathogenesis and to develop effective therapeutic strategies.
Collapse
Affiliation(s)
- Geneviève Rougon
- Aix-Marseille Université, CNRS, Institut des Neurosciences de la Timone, UMR 7289, Marseille, France
| | - Sophie Brasselet
- Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, Marseille, France
| | - Franck Debarbieux
- Aix-Marseille Université, CNRS, Institut des Neurosciences de la Timone, UMR 7289, Marseille, France
| |
Collapse
|
12
|
A thermodynamic analysis of the effects of myelin basic protein (MBP) on DPPS and DPPG monolayers. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2016.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
13
|
Vadakkan KI. Rapid chain generation of interpostsynaptic functional LINKs can trigger seizure generation: Evidence for potential interconnections from pathology to behavior. Epilepsy Behav 2016; 59:28-41. [PMID: 27085478 DOI: 10.1016/j.yebeh.2016.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 11/28/2022]
Abstract
The experimental finding that a paroxysmal depolarizing shift (PDS), an electrophysiological correlate of seizure activity, is a giant excitatory postsynaptic potential (EPSP) necessitates a mechanism for spatially summating several EPSPs at the level of the postsynaptic terminals (dendritic spines). In this context, we will examine reversible interpostsynaptic functional LINKs (IPLs), a proposed mechanism for inducing first-person virtual internal sensations of higher brain functions concurrent with triggering behavioral motor activity for possible pathological changes that may contribute to seizures. Pathological conditions can trigger a rapid chain generation and propagation of different forms of IPLs leading to seizure generation. A large number of observations made at different levels during both ictal and interictal periods are explained by this mechanism, including the tonic and clonic motor activity, different types of hallucinations, loss of consciousness, gradual worsening of cognitive abilities, a relationship with kindling (which uses an augmented stimulation protocol than that used for inducing long-term potentiation (LTP), which is an electrophysiological correlate of behavioral makers of internal sensation of memory), effect of a ketogenic diet on seizure prevention, dendritic spine loss in seizure disorders, neurodegenerative changes, and associated behavioral changes. The interconnectable nature of these findings is explained as loss of function states of a proposed normal functioning of the nervous system.
Collapse
|
14
|
|
15
|
Banquy X, Lee DW, Kristiansen K, Gebbie MA, Israelachvili JN. Interaction Forces between Supported Lipid Bilayers in the Presence of PEGylated Polymers. Biomacromolecules 2015; 17:88-97. [PMID: 26619081 DOI: 10.1021/acs.biomac.5b01216] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using the surface forces apparatus (SFA), interaction forces between supported lipid bilayers were measured in the presence of polyethylene glycol and two other commercially available pegylated triblock polymers, Pluronic F68 and F127. Pluronic F68 has a smaller central hydrophobic block compared to F127 and therefore is more hydrophilic. The study aimed to unravel the effects of polymer architecture and composition on the interactions between the bilayers. Our keys findings show that below the critical aggregation concentration (CAC) of the polymers, a soft, weakly anchored, polymer layer is formed on the surface of the bilayers. The anchoring strength of this physisorbed layer was found to increase significantly with the size of the hydrophobic block of the polymer, and was strongest for the more hydrophobic polymer, F127. Above the CAC, a dense polymer layer, exhibiting gel-like properties, was found to rapidly grow on the bilayers even after mechanical disruption. The cohesive interaction maintaining the gel layer structure was found to be stronger for F127, and was also found to promote the formation of highly structured aggregates on the bilayers.
Collapse
Affiliation(s)
- Xavier Banquy
- Canada Research Chair in Bio-Inspired Materials, Faculté de Pharmacie, Université de Montréal , C.P. 6128, Succursale Centre-ville, Montréal, Québec H3T1J4, Canada
| | | | | | | | | |
Collapse
|
16
|
Rapp MV, Donaldson SH, Gebbie MA, Gizaw Y, Koenig P, Roiter Y, Israelachvili JN. Effects of Surfactants and Polyelectrolytes on the Interaction between a Negatively Charged Surface and a Hydrophobic Polymer Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:8013-21. [PMID: 26135325 DOI: 10.1021/acs.langmuir.5b01781] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We have measured and characterized how three classes of surface-active molecules self-assemble at, and modulate the interfacial forces between, a negatively charged mica surface and a hydrophobic end-grafted polydimethylsiloxane (PDMS) polymer surface in solution. We provide a broad overview of how chemical and structural properties of surfactant molecules result in different self-assembled structures at polymer and mineral surfaces, by studying three characteristic surfactants: (1) an anionic aliphatic surfactant, sodium dodecyl sulfate (SDS), (2) a cationic aliphatic surfactant, myristyltrimethylammonium bromide (MTAB), and (3) a silicone polyelectrolyte with a long-chain PDMS midblock and multiple cationic end groups. Through surface forces apparatus measurements, we show that the separate addition of three surfactants can result in interaction energies ranging from fully attractive to fully repulsive. Specifically, SDS adsorbs at the PDMS surface as a monolayer and modifies the monotonic electrostatic repulsion to a mica surface. MTAB adsorbs at both the PDMS (as a monolayer) and the mica surface (as a monolayer or bilayer), resulting in concentration-dependent interactions, including a long-range electrostatic repulsion, a short-range steric hydration repulsion, and a short-range hydrophobic attraction. The cationic polyelectrolyte adsorbs as a monolayer on the PDMS and causes a long-range electrostatic attraction to mica, which can be modulated to a monotonic repulsion upon further addition of SDS. Therefore, through judicious selection of surfactants, we show how to modify the magnitude and sign of the interaction energy at different separation distances between hydrophobic and hydrophilic surfaces, which govern the static and kinetic stability of colloidal dispersions. Additionally, we demonstrate how the charge density of silicone polyelectrolytes modifies both their self-assembly at polymer interfaces and the robust adhesion of thin PDMS films to target surfaces.
Collapse
Affiliation(s)
- Michael V Rapp
- †Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Stephen H Donaldson
- †Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Matthew A Gebbie
- ‡Materials Department, University of California, Santa Barbara, California 93106-5050, United States
| | | | | | | | - Jacob N Israelachvili
- †Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
- ‡Materials Department, University of California, Santa Barbara, California 93106-5050, United States
| |
Collapse
|
17
|
Lee DW, Kristiansen K, Donaldson SH, Cadirov N, Banquy X, Israelachvili JN. Real-time intermembrane force measurements and imaging of lipid domain morphology during hemifusion. Nat Commun 2015; 6:7238. [PMID: 26006266 PMCID: PMC4455132 DOI: 10.1038/ncomms8238] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/20/2015] [Indexed: 12/19/2022] Open
Abstract
Membrane fusion is the core process in membrane trafficking and is essential for cellular transport of proteins and other biomacromolecules. During protein-mediated membrane fusion, membrane proteins are often excluded from the membrane–membrane contact, indicating that local structural transformations in lipid domains play a major role. However, the rearrangements of lipid domains during fusion have not been thoroughly examined. Here using a newly developed Fluorescence Surface Forces Apparatus (FL-SFA), migration of liquid-disordered clusters and depletion of liquid-ordered domains at the membrane–membrane contact are imaged in real time during hemifusion of model lipid membranes, together with simultaneous force–distance and lipid membrane thickness measurements. The load and contact time-dependent hemifusion results show that the domain rearrangements decrease the energy barrier to fusion, illustrating the significance of dynamic domain transformations in membrane fusion processes. Importantly, the FL-SFA can unambiguously correlate interaction forces and in situ imaging in many dynamic interfacial systems. During membrane fusion, lipid bilayers come into direct contact but rearrangements of lipid domains during fusion have not been thoroughly examined. Here the authors observe and correlate membrane morphology, interaction forces and domain rearrangements during hemifusion of two model membranes.
Collapse
Affiliation(s)
- Dong Woog Lee
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
| | - Kai Kristiansen
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
| | - Stephen H Donaldson
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
| | - Nicholas Cadirov
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
| | - Xavier Banquy
- Canada Research Chair in Bio-inspired Materials and Interfaces, Faculty of Pharmacy, Université de Montréal, C.P. 6128, Succursale Centre Ville, Montréal, Quebec H3C 3J7, Canada
| | - Jacob N Israelachvili
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA.,Department of Materials, University of California, Santa Barbara, California 93106, USA
| |
Collapse
|
18
|
Lee DW, Banquy X, Kristiansen K, Min Y, Ramachandran A, Boggs JM, Israelachvili JN. Adsorption mechanism of myelin basic protein on model substrates and its bridging interaction between the two surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3159-3166. [PMID: 25706854 DOI: 10.1021/acs.langmuir.5b00145] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Myelin basic protein (MBP) is an intrinsically disordered (unstructured) protein known to play an important role in the stability of myelin's multilamellar membrane structure in the central nervous system. The adsorption of MBP and its capacity to interact with and bridge solid substrates has been studied using a surface forces apparatus (SFA) and a quartz crystal microbalance with dissipation (QCM-D). Adsorption experiments show that MBP molecules adsorb to the surfaces in a swollen state before undergoing a conformational change into a more compact structure with a thickness of ∼3 nm. Moreover, this compact structure is able to interact with nearby mica surfaces to form adhesive bridges. The measured adhesion force (energy) between two bridged surfaces is 1.0 ± 0.1 mN/m, (Ead = 0.21 ± 0.02 mJ/m(2)), which is slightly smaller than our previously reported adhesion force of 1.7 mN/m (Ead = 0.36 mJ/m(2)) for MBP adsorbed on two supported lipid bilayers (Lee et al., Proc. Natl. Acad. Sci. U.S.A. 2014, 111, E768-E775). The saturated surface concentration of compact MBP on a single SiO2 surface reaches a stable value of 310 ± 10 ng/cm(2) regardless of the bulk MBP concentration. A kinetic three-step adsorption model was developed that accurately fits the adsorption data. The developed model is a general model, not limited to intrinsically disordered proteins, that can be extended to the adsorption of various chemical compounds that undergo chemical reactions and/or conformational changes upon adsorbing to surfaces. Taken together with our previously published data (Lee et al., Proc. Natl. Acad. Sci. U.S.A. 2014, 111, E768-E775), the present results confirm that conformational changes of MBP upon adsorption are a key for strong adhesion, and that such conformational changes are strongly dependent on the nature of the surfaces.
Collapse
Affiliation(s)
- Dong Woog Lee
- †Department of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Xavier Banquy
- ‡Canada Research Chair in Bio-inspired Materials and Interfaces, Faculty of Pharmacy, Université de Montréal C.P. 6128, succursale Centre Ville, Montréal, Québec H3C 3J7, Canada
| | - Kai Kristiansen
- †Department of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Younjin Min
- §Department of Polymer Engineering, University of Akron, Akron, Ohio United States
| | - Arun Ramachandran
- ∥Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Joan M Boggs
- ⊥Department of Molecular Structure and Function, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- #Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5G 1L5, Canada
| | - Jacob N Israelachvili
- †Department of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
- ∇Materials Department, University of California, Santa Barbara, California 93106, United States
| |
Collapse
|
19
|
Donaldson SH, Røyne A, Kristiansen K, Rapp MV, Das S, Gebbie MA, Lee DW, Stock P, Valtiner M, Israelachvili J. Developing a general interaction potential for hydrophobic and hydrophilic interactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:2051-64. [PMID: 25072835 DOI: 10.1021/la502115g] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We review direct force measurements on a broad class of hydrophobic and hydrophilic surfaces. These measurements have enabled the development of a general interaction potential per unit area, W(D) = -2γ(i)Hy exp(-D/D(H)) in terms of a nondimensional Hydra parameter, Hy, that applies to both hydrophobic and hydrophilic interactions between extended surfaces. This potential allows one to quantitatively account for additional attractions and repulsions not included in the well-known combination of electrostatic double layer and van der Waals theories, the so-called Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The interaction energy is exponentially decaying with decay length D(H) ≈ 0.3-2 nm for both hydrophobic and hydrophilic interactions, with the exact value of D(H) depending on the precise system and conditions. The pre-exponential factor depends on the interfacial tension, γ(i), of the interacting surfaces and Hy. For Hy > 0, the interaction potential describes interactions between partially hydrophobic surfaces, with the maximum hydrophobic interaction (i.e., two fully hydrophobic surfaces) corresponding to Hy = 1. Hydrophobic interactions between hydrophobic monolayer surfaces measured with the surface forces apparatus (SFA) are shown to be well described by the proposed interaction potential. The potential becomes repulsive for Hy < 0, corresponding to partially hydrophilic (hydrated) interfaces. Hydrated surfaces such as mica, silica, and lipid bilayers are discussed and reviewed in the context of the values of Hy appropriate for each system.
Collapse
Affiliation(s)
- Stephen H Donaldson
- Department of Chemical Engineering, University of California , Santa Barbara, California 93106-5080, United States
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Lipid domains control myelin basic protein adsorption and membrane interactions between model myelin lipid bilayers. Proc Natl Acad Sci U S A 2014; 111:E768-75. [PMID: 24516125 DOI: 10.1073/pnas.1401165111] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The surface forces apparatus and atomic force microscope were used to study the effects of lipid composition and concentrations of myelin basic protein (MBP) on the structure of model lipid bilayers, as well as the interaction forces and adhesion between them. The lipid bilayers had a lipid composition characteristic of the cytoplasmic leaflets of myelin from "normal" (healthy) and "disease-like" [experimental allergic encephalomyelitis (EAE)] animals. They showed significant differences in the adsorption mechanism of MBP. MBP adsorbs on normal bilayers to form a compact film (3-4 nm) with strong intermembrane adhesion (∼0.36 mJ/m(2)), in contrast to its formation of thicker (7-8 nm) swelled films with weaker intermembrane adhesion (∼0.13 mJ/m(2)) on EAE bilayers. MBP preferentially adsorbs to liquid-disordered submicron domains within the lipid membranes, attributed to hydrophobic attractions. These results show a direct connection between the lipid composition of membranes and membrane-protein adsorption mechanisms that affects intermembrane spacing and adhesion and has direct implications for demyelinating diseases.
Collapse
|
21
|
Israelachvili JN, Kristiansen K, Gebbie MA, Lee DW, Donaldson SH, Das S, Rapp MV, Banquy X, Valtiner M, Yu J. The Intersection of Interfacial Forces and Electrochemical Reactions. J Phys Chem B 2013; 117:16369-87. [DOI: 10.1021/jp408144g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jacob N. Israelachvili
- Department
of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
- Materials
Department, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Kai Kristiansen
- Department
of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Matthew A. Gebbie
- Materials
Department, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Dong Woog Lee
- Department
of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Stephen H. Donaldson
- Department
of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Saurabh Das
- Department
of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Michael V. Rapp
- Department
of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Xavier Banquy
- Faculty
of Pharmacy, Universite de Montreal, Succursale Centre Ville Montreal, Quebec H3C 3J7, Canada
| | - Markus Valtiner
- Interface
Chemistry and Surface Engineering, Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf, Germany
| | - Jing Yu
- NanoSystems
Biology Cancer Center and Kavli Nanoscience Institute, Division of
Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| |
Collapse
|
22
|
Lee DW, Lim C, Israelachvili JN, Hwang DS. Strong adhesion and cohesion of chitosan in aqueous solutions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:14222-9. [PMID: 24138057 PMCID: PMC3888206 DOI: 10.1021/la403124u] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Chitosan, a load-bearing biomacromolecule found in the exoskeletons of crustaceans and insects, is a promising biopolymer for the replacement of synthetic plastic compounds. Here, surface interactions mediated by chitosan in aqueous solutions, including the effects of pH and contact time, were investigated using a surface forces apparatus (SFA). Chitosan films showed an adhesion to mica for all tested pH ranges (3.0-8.5), achieving a maximum value at pH 3.0 after a contact time of 1 h (Wad ~ 6.4 mJ/m(2)). We also found weak or no cohesion between two opposing chitosan layers on mica in aqueous buffer until the critical contact time for maximum adhesion (chitosan-mica) was reached. Strong cohesion (Wco ~ 8.5 mJ/m(2)) between the films was measured with increasing contact times up to 1 h at pH 3.0, which is equivalent to ~60% of the strongest, previously reported, mussel underwater adhesion. Such time-dependent adhesion properties are most likely related to molecular or molecular group reorientations and interdigitations. At high pH (8.5), the solubility of chitosan changes drastically, causing the chitosan-chitosan (cohesion) interaction to be repulsive at all separation distances and contact times. The strong contact time and pH-dependent chitosan-chitosan cohesion and adhesion properties provide new insight into the development of chitosan-based load-bearing materials.
Collapse
Affiliation(s)
- Dong Woog Lee
- Department of Chemical Engineering, University of California at Santa Barbara, CA 93106, USA
| | - Chanoong Lim
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
| | - Jacob N. Israelachvili
- Department of Chemical Engineering, University of California at Santa Barbara, CA 93106, USA
- Materials Department, University of California at Santa Barbara, CA 93106, USA
| | - Dong Soo Hwang
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
- School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
- POSTECH Ocean Science and technology Institute (POSTI), Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
- Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
| |
Collapse
|
23
|
Biological Water Dynamics and Entropy: A Biophysical Origin of Cancer and Other Diseases. ENTROPY 2013. [DOI: 10.3390/e15093822] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
24
|
Kao PH, Chen YJ, Yang SY, Lin SR, Hu WP, Chang LS. Fusogenicity of Naja naja atra cardiotoxin-like basic protein on sphingomyelin vesicles containing oxidized phosphatidylcholine and cholesterol. J Biochem 2013; 153:523-33. [PMID: 23426438 DOI: 10.1093/jb/mvt013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This study investigated the effect of oxidized phosphatidylcholine (oxPC) and cholesterol (Chol) on Naja naja atra cardiotoxin-like basic protein (CLBP)-induced fusion and leakage in sphingomyelin (SM) vesicles. Compared with those on PC/SM/Chol vesicles, CLBP showed a lower activity to induce membrane permeability but a higher fusogenicity on oxPC/SM/Chol vesicles. A reduction in inner-leaflet fusion elucidated that CLBP fusogenicity was not in parallel to its membrane-leakage activity on oxPC/SM/Chol vesicles. The lipid domain formed by Chol and SM supported CLBP fusogenicity on oxPC/SM/Chol vesicles, while oxPC altered the interacted mode of CLBP with oxPC/SM/Chol vesicles as evidenced by Fourier transform infrared spectra analyses and colorimetric phospholipid/polydiacetylene membrane assay. Although CLBP showed similar binding affinity with PC/SM/Chol and oxPC/SM/Chol vesicles, the binding capability of CLBP with PC/SM/Chol and oxPC/SM/Chol vesicles was affected differently by NaCl. This emphasized that CLBP adopted different membrane interaction modes upon binding with PC/SM/Chol and oxPC/SM/Chol vesicles. CLBP induced fusion in vesicles containing oxPC bearing the aldehyde group, and aldehyde scavenger methoxyamine abrogated the CLBP ability to induce oxPC/SM/Chol fusion. Taken together, our data indicate that Chol and oxPC bearing aldehyde group alter the CLBP membrane-binding mode, leading to fusogenicity promotion while reducing the membrane-damaging activity of CLBP.
Collapse
Affiliation(s)
- Pei-Hsiu Kao
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | | | | | | | | | | |
Collapse
|
25
|
Zan GH, Tan C, Deserno M, Lanni F, Lösche M. Hemifusion of giant unilamellar vesicles with planar hydrophobic surfaces: a fluorescence microscopy study. SOFT MATTER 2012; 8:10877-10886. [PMID: 25383087 PMCID: PMC4222682 DOI: 10.1039/c2sm25702e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Vesicle adhesion and fusion to interfaces are frequently used for the construction of biomimetic surfaces in biosensors and drug delivery. Ubiquitous in cell biology, vesicle fusion involves the transformation of two separate membranes into one contiguous lipid bilayer. In distinction, the deposition of vesicle membranes to hydrophobic surfaces requires the transformation of a lipidic bilayer into a monomolecular layer - a topologically distinct process termed hemifusion. Here, we used hydrophobically terminated self-assembled monolayers (SAMs) on solid surfaces to track the hemifusion of fluorescently labeled giant unilamellar vesicles (GUVs) at the single vesicle level with video time resolution (≈53 ms). We observed that a dilute monolayer, consisting of lipid extracted from the outer GUV leaflet, spreads outward across the hydrophobic surface from the vesicle adhesion site. Subsequently, bilayer hemifusion occurs by vesicle rupture near the hydrophobic surface, followed by spreading of lipid in a dense monolayer. GUV lipids thus transfer to the SAM surface in two concentric zones: an outer hemifusion zone comprises lipids drawn from the outer GUV leaflet and an inner hemifusion zone comprises lipids from both the inner and outer GUV leaflets and grows at a rate of ≈1000 µm2 s-1 (dA/dt = 970 ± 430 µm2 s-1 in n = 22 independent experiments). This growth rate is quantitatively consistent with the assumption that the spreading of the monolayer is entirely driven by the difference in surface energies of the hydrophobic and the lipid-covered SAM surfaces, which is dissipated by friction of the spreading monolayer on the SAM. Lipid transfer between the inner and outer GUV leaflets occurs via a hemifusion pore that forms early in the process near the membrane contact site. This pore also permits expulsion of water from the GUV interior as the vesicle contracts onto the contact site.
Collapse
Affiliation(s)
- Goh Haw Zan
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
| | - Cheemeng Tan
- Ray and Stephanie Lane Center for Computational Biology, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
| | - Markus Deserno
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
| | - Frederick Lanni
- Department of Biological Sciences, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
| | - Mathias Lösche
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890, USA
- National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, MD 20899-6102, USA
| |
Collapse
|