1
|
Wang D, Yang Y, Chen F, Lyu Y, Tan W. Network topology-directed design of molecular CPU for cell-like dynamic information processing. SCIENCE ADVANCES 2022; 8:eabq0917. [PMID: 35947658 PMCID: PMC9365278 DOI: 10.1126/sciadv.abq0917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
Natural cells (NCs) can automatically and continuously respond to fluctuant external information and distinguish meaningful stimuli from weak noise depending on their powerful genetic and protein networks. We herein report a network topology-directed design of dynamic molecular processing system (DMPS) as a molecular central processing unit that powers an artificial cell (AC) able to process fluctuant information in its immediate environment similar to NCs. By constructing a mixed cell community, ACs and NCs have synchronous response to fluctuant extracellular stimuli under physiological condition and in a blood vessel-mimic circulation system. We also show that fluctuant bioinformation released by NCs can be received and processed by ACs. The molecular design of DMPS-powered AC is expected to allow a profound understanding of biological systems, advance the construction of intelligent molecular systems, and promote more elegant bioengineering applications.
Collapse
Affiliation(s)
- Dan Wang
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Yani Yang
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Fengming Chen
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Yifan Lyu
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Shenzhen Research Institute, Hunan University, Shenzhen, Guangdong 518000, China
| | - Weihong Tan
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine and College of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| |
Collapse
|
2
|
Peng H, Lelievre A, Landenfeld K, Müller S, Chen IA. Vesicle encapsulation stabilizes intermolecular association and structure formation of functional RNA and DNA. Curr Biol 2022; 32:86-96.e6. [PMID: 34762821 PMCID: PMC8752491 DOI: 10.1016/j.cub.2021.10.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/02/2021] [Accepted: 10/21/2021] [Indexed: 01/12/2023]
Abstract
During the origin of life, encapsulation of RNA inside vesicles is believed to have been a defining feature of the earliest cells (protocells). The confined biophysical environment provided by membrane encapsulation differs from that of bulk solution and has been shown to increase activity as well as evolutionary rate for functional RNA. However, the structural basis of the effect on RNA has not been clear. Here, we studied how encapsulation of the hairpin ribozyme inside model protocells affects ribozyme kinetics, ribozyme folding into the active conformation, and cleavage and ligation activities. We further examined the effect of encapsulation on the folding of a stem-loop RNA structure and on the formation of a triplex structure in a pH-sensitive DNA switch. The results indicate that encapsulation promotes RNA-RNA association, both intermolecular and intramolecular, and also stabilizes tertiary folding, including the docked conformation characteristic of the active hairpin ribozyme and the triplex structure. The effects of encapsulation were sufficient to rescue the activity of folding-deficient mutants of the hairpin ribozyme. Stabilization of multiple modes of nucleic acid folding and interaction thus enhanced the activity of encapsulated nucleic acids. Increased association between RNA molecules may facilitate the formation of more complex structures and cooperative interactions. These effects could promote the emergence of biological functions in an "RNA world" and may have utility in the construction of minimal synthetic cells.
Collapse
Affiliation(s)
- Huan Peng
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA
| | - Amandine Lelievre
- Institute of Biochemistry, University of Greifswald, 17487 Greifswald, Germany
| | | | - Sabine Müller
- Institute of Biochemistry, University of Greifswald, 17487 Greifswald, Germany
| | - Irene A. Chen
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA,Lead Contact:
| |
Collapse
|
3
|
Zhang J, Jin N, Ji N, Chen X, Shen Y, Pan T, Li L, Li S, Zhang W, Huo F. The Encounter of Biomolecules in Metal-Organic Framework Micro/Nano Reactors. ACS APPLIED MATERIALS & INTERFACES 2021; 13:52215-52233. [PMID: 34369162 DOI: 10.1021/acsami.1c09660] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In nature, biochemical reactions often take place in confined spaces, as typically exemplified by cells. As numerous cellular reactors can be integrated to maintain the living system, researchers have made constant efforts to construct cell-like structures for achieving similar transformations in vitro. Micro/nano reactors engineered by polymers and colloids are becoming popular and being applied in many fields, especially there has been an increasing trend toward constructing metal-organic framework (MOF) micro/nano reactors with the thriving of MOF nanotechnologies. Because of the uniform pores of MOFs, the transmission of substances can be regulated more accurately. Along with properties of large specific surface area, functional diversity and precise control of the particle size, MOFs are also ideal platforms for building distinct microenvironments for biological substances. Compared with traditional polymersomes and colloidosomes, the unique characteristics of MOFs render them potent micro/nano reactor shell materials, mimicking cells for applications in enzymatic catalysis, sensing, nanotherapy, vaccine, biodegradation, etc. This review highlights recent signs of progress on the design of MOF micro/nano reactors and their applications in biology, discusses the existing problems, and prospects their promising properties for smarter multifunctional applications.
Collapse
Affiliation(s)
- Jing Zhang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Na Jin
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Ning Ji
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Xinyi Chen
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Yu Shen
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Ting Pan
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Lin Li
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Sheng Li
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Weina Zhang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| | - Fengwei Huo
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P.R. China
| |
Collapse
|
4
|
Soga N, Ota A, Nakajima K, Watanabe R, Ueno H, Noji H. Monodisperse Liposomes with Femtoliter Volume Enable Quantitative Digital Bioassays of Membrane Transporters and Cell-Free Gene Expression. ACS NANO 2020; 14:11700-11711. [PMID: 32864949 DOI: 10.1021/acsnano.0c04354] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Digital bioassays have emerged as a new category of bioanalysis. However, digital bioassays for membrane transporter proteins have not been well established yet despite high demands in molecular physiology and molecular pharmacology due to the lack of biologically functional monodisperse liposomes with femtoliter volumes. Here, we established a simple and robust method to produce femtoliter-sized liposomes (femto-liposomes). We prepared 106 monodispersed water-in-oil droplets stabilized by a lipid monolayer using a polyethylene glycol-coated femtoliter reactor array device. Droplets were subjected to the optimized emulsion transfer process for femto-liposome production. Liposomes were monodispersed (coefficient of variation = 5-15%) and had suitable diameter (0.6-5.3 μm) and uniform volumes of subfemtoliter or a few femtoliters; thus, they were termed uniform femto-liposomes. The unilamellarity of uniform femto-liposomes allowed quantitative single-molecule analysis of passive and active transporter proteins: α-hemolysin and FoF1-ATPase. Digital gene expression in uniform femto-liposomes (cell-free transcription and translation from single DNA molecules) was also demonstrated, showing the versatility of digital assays for membrane transporter proteins and cell-free synthetic biology.
Collapse
Affiliation(s)
- Naoki Soga
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Akira Ota
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kota Nakajima
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Rikiya Watanabe
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- PRIME, Japan Agency for Medical Research and Development, 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan
| | - Hiroshi Ueno
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Hiroyuki Noji
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| |
Collapse
|
5
|
Katsuta S, Okano T, Koiwai K, Suzuki H. Ejection of Large Particulate Materials from Giant Unilamellar Vesicles Induced by Electropulsation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13196-13204. [PMID: 31498647 DOI: 10.1021/acs.langmuir.9b01617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electroporation or electropermealization is a technique to open pores in the lipid bilayer membrane of cells and vesicles transiently to increase its permeability to otherwise impermeable molecules. However, the upper size limit of the materials permeable through this operation has not been studied in the past. Here, we investigate the size of the material that can be released (ejected) from giant unilamellar vesicles (GUVs) upon electrical pulsation. We confirm that the volume of GUV shrinks in a stepwise manner upon periodical pulsation, in accordance with previous studies. When the same operation is applied to GUVs that encapsulate microbeads, we find that beads as large as 20 μm can be ejected across the membrane without rupturing the whole GUV structure. We also demonstrate that functional bioactive particulate materials, such as gel balls, vesicles, and cells can be encapsulated in and ejected from GUVs. We foresee that this phenomenon can be applied to precisely regulate the time and location of release of these particulate materials in the microenvironment.
Collapse
Affiliation(s)
- Shota Katsuta
- Dept. Precision Mechanics, Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , Tokyo 112-8551 , Japan
| | - Taiji Okano
- Dept. Precision Mechanics, Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , Tokyo 112-8551 , Japan
| | - Keiichiro Koiwai
- Dept. Precision Mechanics, Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , Tokyo 112-8551 , Japan
- Japan Society for the Promotion of Science (JSPS) , 5-3-1 Kojimachi , Chiyoda-ku , Tokyo 102-0083 , Japan
| | - Hiroaki Suzuki
- Dept. Precision Mechanics, Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , Tokyo 112-8551 , Japan
| |
Collapse
|
6
|
Chan MA, Hinman NW, Potter-McIntyre SL, Schubert KE, Gillams RJ, Awramik SM, Boston PJ, Bower DM, Des Marais DJ, Farmer JD, Jia TZ, King PL, Hazen RM, Léveillé RJ, Papineau D, Rempfert KR, Sánchez-Román M, Spear JR, Southam G, Stern JC, Cleaves HJ. Deciphering Biosignatures in Planetary Contexts. ASTROBIOLOGY 2019; 19:1075-1102. [PMID: 31335163 PMCID: PMC6708275 DOI: 10.1089/ast.2018.1903] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 03/10/2019] [Indexed: 05/05/2023]
Abstract
Microbial life permeates Earth's critical zone and has likely inhabited nearly all our planet's surface and near subsurface since before the beginning of the sedimentary rock record. Given the vast time that Earth has been teeming with life, do astrobiologists truly understand what geological features untouched by biological processes would look like? In the search for extraterrestrial life in the Universe, it is critical to determine what constitutes a biosignature across multiple scales, and how this compares with "abiosignatures" formed by nonliving processes. Developing standards for abiotic and biotic characteristics would provide quantitative metrics for comparison across different data types and observational time frames. The evidence for life detection falls into three categories of biosignatures: (1) substances, such as elemental abundances, isotopes, molecules, allotropes, enantiomers, minerals, and their associated properties; (2) objects that are physical features such as mats, fossils including trace-fossils and microbialites (stromatolites), and concretions; and (3) patterns, such as physical three-dimensional or conceptual n-dimensional relationships of physical or chemical phenomena, including patterns of intermolecular abundances of organic homologues, and patterns of stable isotopic abundances between and within compounds. Five key challenges that warrant future exploration by the astrobiology community include the following: (1) examining phenomena at the "right" spatial scales because biosignatures may elude us if not examined with the appropriate instrumentation or modeling approach at that specific scale; (2) identifying the precise context across multiple spatial and temporal scales to understand how tangible biosignatures may or may not be preserved; (3) increasing capability to mine big data sets to reveal relationships, for example, how Earth's mineral diversity may have evolved in conjunction with life; (4) leveraging cyberinfrastructure for data management of biosignature types, characteristics, and classifications; and (5) using three-dimensional to n-D representations of biotic and abiotic models overlain on multiple overlapping spatial and temporal relationships to provide new insights.
Collapse
Affiliation(s)
- Marjorie A. Chan
- Department of Geology & Geophysics, University of Utah, Salt Lake City, Utah
| | - Nancy W. Hinman
- Department of Geosciences, University of Montana, Missoula, Montana
| | | | - Keith E. Schubert
- Department of Electrical and Computer Engineering, Baylor University, Waco, Texas
| | - Richard J. Gillams
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Electronics and Computer Science, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Stanley M. Awramik
- Department of Earth Science, University of California, Santa Barbara, Santa Barbara, California
| | - Penelope J. Boston
- NASA Astrobiology Institute, NASA Ames Research Center, Moffett Field, California
| | - Dina M. Bower
- Department of Astronomy, University of Maryland College Park (CRESST), College Park, Maryland
- NASA Goddard Space Flight Center, Greenbelt, Maryland
| | | | - Jack D. Farmer
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona
| | - Tony Z. Jia
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Penelope L. King
- Research School of Earth Sciences, The Australian National University, Canberra, Australia
| | - Robert M. Hazen
- Geophysical Laboratory, Carnegie Institution for Science, Washington, District of Columbia
| | - Richard J. Léveillé
- Department of Earth and Planetary Sciences, McGill University, Montreal, Canada
- Geosciences Department, John Abbott College, Sainte-Anne-de-Bellevue, Canada
| | - Dominic Papineau
- London Centre for Nanotechnology, University College London, London, United Kingdom
- Department of Earth Sciences, University College London, London, United Kingdom
- Centre for Planetary Sciences, University College London, London, United Kingdom
- BioGeology and Environmental Geology State Key Laboratory, School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Kaitlin R. Rempfert
- Department of Geological Sciences, University of Colorado Boulder, Boulder, Colorado
| | - Mónica Sánchez-Román
- Earth Sciences Department, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - John R. Spear
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado
| | - Gordon Southam
- School of Earth and Environmental Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | | | - Henderson James Cleaves
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Program in Interdisciplinary Studies, Institute for Advanced Study, Princeton, New Jersey
| |
Collapse
|
7
|
Blanken D, van Nies P, Danelon C. Quantitative imaging of gene-expressing liposomes reveals rare favorable phenotypes. Phys Biol 2019; 16:045002. [PMID: 30978176 DOI: 10.1088/1478-3975/ab0c62] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The biosynthesis of proteins from genomic DNA is a universal process in every living organism. Building a synthetic cell using separate biological parts hence implies to reconstitute a minimal gene expression apparatus and to compartmentalize it in a cell-mimicking environment. Previous studies have demonstrated that the PURE (Protein synthesis Using Recombinant Elements) system could be functionally encapsulated inside lipid vesicles. However, quantitative insights on functional consequences of spatial confinement of PURE system reactions remain scarce, which has hampered the full exploitation of gene-expressing liposomes as the fundamental unit to build an artificial cell. We report on direct imaging of tens of thousands of gene-expressing liposomes per sample allowing us to assess sub-population features in a statistically relevant manner. Both the vesicle size (diameter <10 μm) and lipid composition (mixture of phospholipids with zwitterionic and negatively charged headgroups, including cardiolipin) are compatible with the properties of bacterial cells. Therefore, our liposomes provide a suitable chassis to host the Escherichia coli-derived PURE translation machinery and other bacterial processes in future developments. The potential of high-content imaging to identify rare phenotypes is demonstrated by the fact that a subset of the liposome population exhibits a remarkably high yield of synthesized protein or a prolonged expression lifespan that surpasses the performance of ensemble liposome-averaged and bulk reactions. Among the three commercial PURE systems tested, PUREfrex2.0 offers the most favorable phenotypes displaying both high yield and long protein synthesis lifespan. Moreover, probing membrane permeability reveals a large heterogeneity amongst liposomes. In situ expression and membrane embedding of the pore-forming connexin leads to a characteristic permeability time profile, while increasing the fraction of permeable liposomes in the population. We see diversity in gene expression dynamics and membrane permeability as an opportunity to complement a rational design approach aiming at further implementing biological functions in liposome-based synthetic cells.
Collapse
Affiliation(s)
- Duco Blanken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | | | | |
Collapse
|
8
|
Tsugane M, Suzuki H. Reverse Transcription Polymerase Chain Reaction in Giant Unilamellar Vesicles. Sci Rep 2018; 8:9214. [PMID: 29907779 PMCID: PMC6003926 DOI: 10.1038/s41598-018-27547-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/04/2018] [Indexed: 02/07/2023] Open
Abstract
We assessed the applicability of giant unilamellar vesicles (GUVs) for RNA detection using in vesicle reverse transcription polymerase chain reaction (RT-PCR). We prepared GUVs that encapsulated one-pot RT-PCR reaction mixture including template RNA, primers, and Taqman probe, using water-in-oil emulsion transfer method. After thermal cycling, we analysed the GUVs that exhibited intense fluorescence signals, which represented the cDNA amplification. The detailed analysis of flow cytometry data demonstrated that rRNA and mRNA in the total RNA can be amplified from 10–100 copies in the GUVs with 5–10 μm diameter, although the fraction of reactable GUV was approximately 60% at most. Moreover, we report that the target RNA, which was directly transferred into the GUV reactors via membrane fusion, can be amplified and detected using in vesicle RT-PCR. These results suggest that the GUVs can be used as biomimetic reactors capable of performing PCR and RT-PCR, which are important in analytical and diagnostic applications with additional functions.
Collapse
Affiliation(s)
- Mamiko Tsugane
- Department of Precision Mechanics, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, Japan.,Japan Society for the Promotion of Science (JSPS), 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, Japan
| | - Hiroaki Suzuki
- Department of Precision Mechanics, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, Japan.
| |
Collapse
|
9
|
Sunami T, Shimada K, Tsuji G, Fujii S. Flow Cytometric Analysis To Evaluate Morphological Changes in Giant Liposomes As Observed in Electrofusion Experiments. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:88-96. [PMID: 29215888 DOI: 10.1021/acs.langmuir.7b03317] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Liposome fusion is a way of supplying additional components for in-liposome biochemical reactions. Electrofusion is a method that does not require the addition of fusogens, which often alter the liposome dispersion, and is therefore useful for repetitive liposome fusion. However, the details of electrofusion have not been elucidated because of the limitations surrounding observing liposomes using a microscope. Therefore, we introduced fluorescent markers and high-throughput flow cytometry to analyze the morphological changes that occur in liposome electrofusion. (i) The content mixing was evaluated by a calcein-Co2+-EDTA system, in which green fluorescence from dequenched free calcein is detected when the quenched calcein-Co2+ complex and EDTA are mixed together. (ii) Liposome destruction was evaluated from the decrease in the total membrane volume of giant liposomes. (iii) Liposome fission was evaluated from the increase in the number of giant liposomes. By applying the flow cytometric analysis, we investigated the effect of three parameters (DC pulse, AC field, and lipid composition) on liposome electrofusion. The larger numbers or higher voltages of DC pulses induced liposome fusion and destruction with higher probability. The longer application time of the AC field induced liposome fusion, fission, and destruction with higher probability. Higher content of negatively charged POPG (≥19%) strongly inhibited liposome electrofusion.
Collapse
Affiliation(s)
| | | | | | - Satoshi Fujii
- Kanagawa Institute of Industrial Science and Technology, KSP EAST303, 3-2-1 Sakado, Takatsu-Ku, Kawasaki, Kanagawa 213-0012, Japan
| |
Collapse
|