scholarly journals Environment-Sensitive Intelligent Self-Reproducing Artificial Cell with a Modification-Active Lipo-Deoxyribozyme

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 606 ◽  
Author(s):  
Muneyuki Matsuo ◽  
Yuiko Hirata ◽  
Kensuke Kurihara ◽  
Taro Toyota ◽  
Toru Miura ◽  
...  
Keyword(s):  
Information Flow ◽  
Morphological Changes ◽  
Membrane Surface ◽  
Phenotypic Expression ◽  
Dna Amplification ◽  
Molecular Machines ◽  
Starvation Period ◽  
Artificial Cells ◽  
Artificial Cell ◽  
And Robotics

As a supramolecular micromachine with information flow, a giant vesicle (GV)-based artificial cell that exhibits a linked proliferation between GV reproduction and internal DNA amplification has been explored in this study. The linked proliferation is controlled by a complex consisting of GV membrane-intruded DNA with acidic amphiphilic catalysts, working overall as a lipo-deoxyribozyme. Here, we investigated how a GV-based artificial cell containing this lipo-deoxyribozyme responds to diverse external and internal environments, changing its proliferative dynamics. We observed morphological changes (phenotypic expression) in GVs induced by the addition of membrane precursors with different intervals of addition (starvation periods). First, we focused on a new phenotype, the “multiple tubulated” form, which emerged after a long starvation period. Compared to other forms, the multiple tubulated form is characterized by a larger membrane surface with a heavily cationic charge. A second consideration is the effect of the chain length of encapsulated DNA on competitive proliferation. The competitive proliferation among three different species of artificial cells containing different lengths of DNA was investigated. The results clearly showed a distinct intervention in the proliferation dynamics of the artificial cells with each other. In this sense, our GV-based artificial cell can be regarded as an intelligent supramolecular machine responding to external and internal environments, providing a new concept for developing molecular machines and robotics.

scholarly journals Self-Propulsion Strategies for Artificial Cell-Like Compartments

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1680 ◽  
Author(s):  
Ibon Santiago ◽  
Friedrich C. Simmel
Keyword(s):  
Synthetic Biology ◽  
Biomedical Engineering ◽  
Recent Progress ◽  
Emulsion Droplet ◽  
Artificial Cells ◽  
Droplet Motion ◽  
Active Particles ◽  
Artificial Cell ◽  
Catalytically Active ◽  
A Current

Reconstitution of life-like properties in artificial cells is a current research frontier in synthetic biology. Mimicking metabolism, growth, and sensing are active areas of investigation; however, achieving motility and directional taxis are also challenging in the context of artificial cells. To tackle this problem, recent progress has been made that leverages the tools of active matter physics in synthetic biology. This review surveys the most significant achievements in designing motile cell-like compartments. In this context, strategies for self-propulsion are summarized, including, compartmentalization of catalytically active particles, phoretic propulsion of vesicles and emulsion droplet motion driven by Marangoni flows. This work showcases how the realization of motile protocells may impact biomedical engineering while also aiming at answering fundamental questions in locomotion of prebiotic cells.

Hemoperfusion Based on Artificial Cells for Aluminium and Iron Removal, Immunosorption, Fulminant Hepatic Failure, Uremia, Poisoning and Metabolic Assists

1986 ◽  
Vol 9 (5) ◽  
pp. 285-288 ◽  
Author(s):  
T.M.S. Chang
Keyword(s):  
Fulminant Hepatic Failure ◽  
Hepatic Failure ◽  
Activated Charcoal ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Research Centre ◽  
Artificial Cells ◽  
Artificial Cell ◽  
Volume Relationship ◽  
Charcoal Hemoperfusion

The author reviewed artificial cells and their applications in hemoperfusion for chronic renal failure, poisoning, fulminant hepatic failure, removal of aluminium and iron, and metabolic assists. Other areas reviewed included artificial cells containing enzymes, multienzymes, immunosorbents, cell cultures and other areas. Artificial cells can be formed as membrane coated adsorbent or microencapsulated adsorbent, enzymes and cells (1-3). The large surface to volume relationship and the ultrathin membrane of artificial cells allows the rapid equilibration of metabolites (1-3). Artificial cells containing enzymes, ion exchange resin and activated charcoal have been used for hemoperfusion (4). The microencapsulated or membrane coated absorbents, enzymes, cells, immunosorbents and other material are prevented from releasing unwanted material into the circulation and prevented from adverse effects on blood cells. Because of the problem of charcoal in releasing emboli and depleting platelets (5) we first developed coated activated charcoal hemoperfusion for clinical application (6, 7). This has been used extensively in clinical studies. The artificial cell approach has also been applied to a number of other hemoperfusion approaches. The lack of space only allows this paper to summarize some of the approaches originated from this research centre.

scholarly journals Capillary endothelial cell cultures: phenotypic modulation by matrix components.

1983 ◽  
Vol 97 (1) ◽  
pp. 153-165 ◽  
Author(s):  
J A Madri ◽  
S K Williams
Keyword(s):  
Endothelial Cells ◽  
Basement Membrane ◽  
Membrane Surface ◽  
Phenotypic Expression ◽  
Aortic Endothelial Cells ◽  
Capillary Endothelial Cells ◽  
Endothelial Cell Cultures ◽  
Cell Densities

Capillary endothelial cells of rat epididymal fat pad were isolated and cultured in media conditioned by bovine aortic endothelial cells and substrata consisting of interstitial or basement membrane collagens. When these cells were grown on interstitial collagens they underwent proliferation, formed a continuous cell layer and, if cultured for long periods of time, formed occasional tubelike structures. In contrast, when these cells were grown on basement membrane collagens, they did not proliferate but did aggregate and form tubelike structures at early culture times. In addition, cells grown on basement membrane substrata expressed more basement membrane constituents as compared with cells grown on interstitial matrices when assayed by immunoperoxidase methods and quantitated by enzyme-linked immunosorbent inhibition assays. Furthermore, when cells were grown on either side of washed, acellular amnionic membranes their phenotypes were markedly different. On the basement membrane surface they adhered, spread, and formed tubelike structures but did not migrate through the basement membrane. In contrast, when seeded on the stromal surface, these cells were observed to proliferate and migrate into the stromal aspect of the amnion and ultimately formed tubelike structures at high cell densities at longer culture periods (21 d). Thus, connective tissue components play important roles in regulating the phenotypic expression of capillary endothelial cells in vitro, and similar roles of the collagenous components of the extracellular matrix may exist in vivo following injury and during angiogenesis. Furthermore, the culture systems outlined here may be of use in the further study of differentiated, organized capillary endothelial cells in culture.

scholarly journals Protein synthesis in artificial cells: using compartmentalisation for spatial organisation in vesicle bioreactors

2015 ◽  
Vol 17 (24) ◽  
pp. 15534-15537 ◽  
Author(s):  
Yuval Elani ◽  
Robert V. Law ◽  
Oscar Ces
Keyword(s):  
Protein Synthesis ◽  
Protein Expression ◽  
Artificial Cells ◽  
Spatial Organisation ◽  
Artificial Cell

Spatially segregated in vitro protein expression in a vesicle-based artificial cell, with different proteins synthesised in defined vesicle regions.

scholarly journals An artificial cell containing cyanobacteria for endosymbiosis mimicking

2021 ◽  
Author(s):  
Boyu Yang ◽  
Shubin Li ◽  
Wei Mu ◽  
Zhao Wang ◽  
Xiaojun Han
Keyword(s):  
Lactate Dehydrogenase ◽  
Horseradish Peroxidase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Metabolic Pathways ◽  
Glucose Dehydrogenase ◽  
Working Mechanism ◽  
Artificial Cells ◽  
Amplex Red ◽  
Enzyme Cascade ◽  
Artificial Cell

AbstractThe bottom-up constructed artificial cells help to understand the cell working mechanism and provide the evolution clues for organisms. Cyanobacteria are believed to be the ancestors of chloroplasts according to endosymbiosis theory. Herein we demonstrate an artificial cell containing cyanobacteria to mimic endosymbiosis phenomenon. The cyanobacteria sustainably produce glucose molecules by converting light energy into chemical energy. Two downstream “metabolic” pathways starting from glucose molecules are investigated. One involves enzyme cascade reaction to produce H2O2 (assisted by glucose oxidase) first, followed by converting Amplex red to resorufin (assisted by horseradish peroxidase). The more biological one involves nicotinamide adenine dinucleotide (NADH) production in the presence of NAD+ and glucose dehydrogenase. Further, NADH molecules are oxidized into NAD+ by pyruvate catalyzed by lactate dehydrogenase, meanwhile, lactate is obtained. Therefore, the sustainable cascade cycling of NADH/NAD+ is built. The artificial cells built here simulate the endosymbiosis phenomenon, meanwhile pave the way for investigating more complicated sustainable energy supplied metabolism inside artificial cells.

scholarly journals Altered Na+/K+-ATPase expression plays a role in rumen epithelium adaptation in sheep fed hay ad libitum or a mixed hay/concentrate diet

2011 ◽  
Vol 56 (No. 1) ◽  
pp. 36-48 ◽  
Author(s):  
J. Kuzinski ◽  
R. Zitnan ◽  
T. Viergutz ◽  
J. Legath ◽  
M. Schweigel
Keyword(s):  
Cell Membrane ◽  
Mrna Expression ◽  
Surface Area ◽  
Morphological Changes ◽  
Membrane Surface ◽  
Membrane Surface Area ◽  
Cell Layers ◽  
Ad Libitum ◽  
Atpase Localization ◽  
Cell Membrane Surface

In this study we investigated rumen papillae morphology and the localization and expression of the<br />Na<sup>+/</sup>K<sup>+</sup>-ATPase&nbsp;in eight sheep fed hay ad libitum (h) or hay ad libitum plus additional concentrate (h/c). Four sheep were provided with the ad libitum h-diet for the complete three-week experimental period. The second group of four sheep received the h-diet for only one week and was fed the mixed hay/concentrate (h/c) diet for another two weeks. The amount of concentrate supplement was stepwise increased from 150 to 1000 g/day and given in two meals. Following slaughter rumen papillae from the atrium ruminis (AR), the rumen ventralis (RV) and the ventral blind sac (BSV) were fixed and examined for morphological changes and Na<sup>+</sup>/K<sup>+</sup>-ATPase localization by morphometric methods and immunohistochemistry. Ruminal epithelial cells (REC) originating from the strata basale to granulosum were also isolated. Cellular Na<sup>+</sup>/K<sup>+</sup>-ATPase expression (mRNA and protein) and differentiation state were determined by RT-PCR, Western blot, and flow cytometry. Compared with data from h-fed sheep, morphometric analysis revealed an increased length and width of rumen papillae in h/c-fed sheep, resulting in a marked 41% and 62% increase in rumen papillae surface in AR and RV, respectively. The rumen mucosa of h/c-fed sheep was characterized by a predominant stratum corneum (42 &plusmn; 0.7 &micro;m vs. 28 &plusmn; 0.5 &micro;m), but the thickness of the metabolically active cell layers remained unchanged. REC suspensions from sheep fed the h/c diet generally contained more cells (7.30 &plusmn; 0.83 vs. 3.49 &plusmn; 0.52 &times; 10<sup>7</sup>/ml; P &lt; 0.001) and an increased proportion of REC positive for basal cytokeratin and for the differentiation marker cytokeratin 10 (P &lt; 0.05). Cellular (cell membrane) and epithelial (stratum basale to stratum granulosum) Na<sup>+</sup>/K<sup>+</sup>-ATPase localization was similar between rumen regions and was not changed by concentrate feeding. After two weeks on the h/c-diet, a 96% increase in the absolute number of Na<sup>+</sup>/K<sup>+</sup>-ATPase-positive REC (6.56 &plusmn; 0.84 vs. 3.35 &plusmn; 0.51 &times; 10<sup>7</sup>/ml; P = 0.003) and a 61% elevation (P = 0.043) in Na<sup>+</sup>/K<sup>+</sup>-ATPase protein expression in REC from the upper third of the suprabasal cell layers were found. Moreover, a two-fold (P = 0.001) elevation in cell membrane surface area accompanied by a reduction (1.19 &times; 10<sup>&ndash;7</sup> &plusmn; 1.72 &times; 10<sup>&ndash;9</sup> arbitrary units (AU)/cm2 vs. 1.73 &times; 10<sup>&ndash;7</sup> &plusmn; 8.16 &times; 10<sup>&ndash;9</sup> AU/cm<sup>2</sup> in the h-group; P &lt; 0.001) in specific Na<sup>+</sup>/K<sup>+</sup>-ATPase fluorescence per cm<sup>2</sup> of cell membrane surface area was observed after h/c-feeding. Na<sup>+</sup>/K<sup>+</sup>-ATPase &alpha; subunit mRNA expression was also reduced (P &lt; 0.0001) from 0.154 &plusmn; 0.013 to 0.057 &plusmn; 0.004 pg per pg S18 mRNA control in the h/c-compared with the h-group. Thus, the h/c-diet led to a rapid increase in REC number and total cell membrane surface area in metabolically active and resorptive cell layers and was accompanied by a reduction in Na<sup>+</sup>/K<sup>+</sup>-ATPase mRNA expression and abundance per cell membrane surface area.

scholarly journals Creation of Artificial Cell-Like Structures Promoted by Microfluidics Technologies

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 216 ◽  
Author(s):  
Yusuke Sato ◽  
Masahiro Takinoue
Keyword(s):  
Low Cost ◽  
Sample Volume ◽  
Future Perspective ◽  
Biological Research ◽  
Artificial Cells ◽  
Research Fields ◽  
Artificial Cell ◽  
Biological Phenomena ◽  
The Creation ◽  
Oil Emulsions

The creation of artificial cells is an immensely challenging task in science. Artificial cells contribute to revealing the mechanisms of biological systems and deepening our understanding of them. The progress of versatile biological research fields has clarified many biological phenomena, and various artificial cell models have been proposed in these fields. Microfluidics provides useful technologies for the study of artificial cells because it allows the fabrication of cell-like compartments, including water-in-oil emulsions and giant unilamellar vesicles. Furthermore, microfluidics also allows the mimicry of cellular functions with chip devices based on sophisticated chamber design. In this review, we describe contributions of microfluidics to the study of artificial cells. Although typical microfluidic methods are useful for the creation of artificial-cell compartments, recent methods provide further benefits, including low-cost fabrication and a reduction of the sample volume. Microfluidics also allows us to create multi-compartments, compartments with artificial organelles, and on-chip artificial cells. We discuss these topics and the future perspective of microfluidics for the study of artificial cells and molecular robotics.

Ultrastructural changes in chloroplasts resulting from fluctuations in NaCl concentration: freeze-fracture of thylakoid membranes in Dunaliella salina

1975 ◽  
Vol 18 (2) ◽  
pp. 287-299 ◽  
Author(s):  
A.O. Pfeifhofer ◽  
J.C. Belton
Keyword(s):  
Salt Concentration ◽  
Dunaliella Salina ◽  
Unit Area ◽  
Morphological Changes ◽  
Membrane Surface ◽  
Freeze Fracture ◽  
Thylakoid Membranes ◽  
Ultrastructural Changes ◽  
Thin Sections ◽  
Number Of Particles

The structure of chloroplasts isolated from Dunaliella salina has been studied with respect to changing concentrations of sodium chloride in the culture medium. Freeze-fracture replicas and thin sections of intact chloroplasts do not exhibit any noticeable changes in structure at concentrations ranging between 3.5 and 25% NaCl. Chloroplasts isolated from algal cells that have been acclimatized to the higher salt concentration show a change in the thylakoid membranes. The thylakoid membranes appear compressed over a major portion of the membrane surface, with only the end of the thylakoid membranes unappressed. The number of particles per unit area on the B face is also altered by the salt concentration. The chloroplasts acclimatized to 25% NaCl have about 3 times the number of particles per unit area on a B face of end-membranes as on a comparable face of thylakoid membranes acclimatized to low (3.5% NaCl) salt concentration. These morphological changes can be reversed if the chloroplasts acclimatized to high or low salt concentrations are returned to a medium of different salt concentration prior to freeze-fracturing.

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