scholarly journals Human Erythrocyte-Like Transformation of Synthetic Polymer Vesicles

2021 ◽  
Author(s):  
Eri Yoshida
Keyword(s):  
Methacrylic Acid ◽  
Human Erythrocyte ◽  
Bilayer Membrane ◽  
Synthetic Polymer ◽  
Butyl Methacrylate ◽  
Temperature Changes ◽  
Polymer Vesicles ◽  
Membrane Perforation ◽  
Response To Temperature ◽  
Spherical Vesicles

Abstract This paper describes that synthetic polymer vesicles undergo a human erythrocyte-like transformation in response to temperature changes. The normally biconcave discoid erythrocytes, i.e., the discocytes, are transformed into various shapes by their environmental stresses. Field emission scanning electron microscopy (FE-SEM) demonstrates that the spherical vesicles consisting of poly(methacrylic acid)-block-poly(n-butyl methacrylate-random-methacrylic acid), PMAA-b-P(BMA-r-MAA), transform into echinocyte-like crenate vesicles due to expansion by the component copolymers in being freed from the vesicle surface when heated in an aqueous methanol solution. An increase in the vesicle concentration transforms the spherical vesicles into stomatocyte-like cup-shaped vesicles via the membrane perforation or double invaginations followed by membrane coupling and fusion. Light scattering studies reveal the reversibility and repeatability of the transformations. These findings indicate that the erythrocyte transformations are attributed to the inherent property of the bilayer membrane. The polymer vesicles are helpful for a better understanding of the biomembrane.

scholarly journals Neuron-like tubule extension of giant polymer vesicles

2021 ◽  
Vol 3 (1) ◽  
pp. 195-202
Author(s):  
Eri Yoshida ◽  
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Methacrylic Acid ◽  
Diblock Copolymers ◽  
Size Structure ◽  
Early Stage ◽  
Monomer Conversion ◽  
Morphological Transformation ◽  
Polymer Vesicles ◽  
Spherical Vesicles

Giant polymer vesicles consisting of amphiphilic diblock copolymers are helpful as artificial biomembrane models based on many similarities in their size, structure, morphological transformation, membrane permeability, etc. This paper describes the creation of neuron-like tubule extension employing the polymer vesicles. The polymerization-induced self-assembly was performed in the presence of micron-sized spherical vesicles consisting of poly(methacrylic acid)-block-poly(methyl methacrylate-random-methacrylic acid), PMAA-b-P(MMA-r-MAA), through the photo nitroxide-mediated controlled/living radical polymerization (photo-NMP) using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (MTEMPO) as the mediator. The photo-NMP of methyl methacrylate (MMA) and methacrylic acid (MAA) was carried out in an aqueous methanol solution (CH3OH/H2O = 3/1 v/v) using poly(methacrylic acid) (PMAA) end-capped with MTEMPO and the spherical vesicles of PMAA141-b-P(MMA0.831-r-MAA0.169)368 with an 11.7-mm diameter. The vesicles projected many processes on their surface during the early stage of the polymerization. As the polymerization progressed, only one or two of the processes extended to thick tubules, accompanied by the slow growth of thin tubules. Further progress of the polymerization elongated the thick tubules and caused branching of the tubules. The tubules had a vesicular structure because cup-like vesicles joined in line were formed during the initial stage of the extension. The polymerization livingness supported the tubule extension based on a linear increase in the molecular weight of the component copolymer and a negligible change in the molecular weight distribution versus the monomer conversion. The spherical vesicles were similar to the neurons in the tubule extension for the initial projection, followed by the elongation and branching. This similarity implies that the neurite extension in the neurons is related to the inherent property of the bilayer membrane.

scholarly journals LPEATs Tailor Plant Phospholipid Composition through Adjusting Substrate Preferences to Temperature

2021 ◽  
Vol 22 (15) ◽  
pp. 8137
Author(s):  
Sylwia Klińska ◽  
Kamil Demski ◽  
Katarzyna Jasieniecka-Gazarkiewicz ◽  
Antoni Banaś
Keyword(s):  
Growth Regulation ◽  
Phylogenetic Analyses ◽  
Phospholipid Composition ◽  
Expression Ratio ◽  
Temperature Changes ◽  
Substrate Preferences ◽  
Thermal Changes ◽  
Biochemical Evaluation ◽  
Response To Temperature ◽  
Acyl Donors

Acyl-CoA:lysophosphatidylethanolamine acyltransferases (LPEATs) are known as enzymes utilizing acyl-CoAs and lysophospholipids to produce phosphatidylethanolamine. Recently, it has been discovered that they are also involved in the growth regulation of Arabidopsis thaliana. In our study we investigated expression of each Camelina sativa LPEAT isoform and their behavior in response to temperature changes. In order to conduct a more extensive biochemical evaluation we focused both on LPEAT enzymes present in microsomal fractions from C. sativa plant tissues, and on cloned CsLPEAT isoforms expressed in yeast system. Phylogenetic analyses revealed that CsLPEAT1c and CsLPEAT2c originated from Camelina hispida, whereas other isoforms originated from Camelina neglecta. The expression ratio of all CsLPEAT1 isoforms to all CsLPEAT2 isoforms was higher in seeds than in other tissues. The isoforms also displayed divergent substrate specificities in utilization of LPE; CsLPEAT1 preferred 18:1-LPE, whereas CsLPEAT2 preferred 18:2-LPE. Unlike CsLPEAT1, CsLPEAT2 isoforms were specific towards very-long-chain fatty acids. Above all, we discovered that temperature strongly regulates LPEATs activity and substrate specificity towards different acyl donors, making LPEATs sort of a sensor of external thermal changes. We observed the presented findings not only for LPEAT activity in plant-derived microsomal fractions, but also for yeast-expressed individual CsLPEAT isoforms.

scholarly journals A Nonaqucous Potentiometric Titration Study of the Dissociation of t-Butyl Methacrylate-Methacrylic Acid Copolymers

2003 ◽  
Vol 19 (5) ◽  
pp. 775-777
Author(s):  
Kiyoharu NAKATANI ◽  
Jun YAMASHITA ◽  
Tomomi SEKINE ◽  
Minoru TORIUMI ◽  
Toshiro ITANI
Keyword(s):  
Potentiometric Titration ◽  
Methacrylic Acid ◽  
Butyl Methacrylate ◽  
Methacrylic Acid Copolymers ◽  
Titration Study

Preparation and Swelling Dynamics Characterization of Poly(N, N-Diethylacrylamide-Co-Itaconic Acid) Intelligent Hydrogels

2012 ◽  
Vol 490-495 ◽  
pp. 3382-3386
Author(s):  
Xiao Qi Li ◽  
Nai Yan Zhang ◽  
Jun Hai Zhang
Keyword(s):  
Itaconic Acid ◽  
Monomer Concentration ◽  
Molar Ratio ◽  
Solution Temperature ◽  
Temperature Changes ◽  
Different Temperatures ◽  
Total Monomer Concentration ◽  
Equilibrium Swelling Ratio ◽  
Composition Ratios ◽  
Response To Temperature

Poly(N,N-diethylacrylamide) (PDEA) hydrogel is known for their intelligent reversible swelling/deswelling behavior in response to temperature changes across a lower critical solution temperature (LCST) at around 31oC. In this study, itaconic acid (IA) was co-polymerized with N, N-diethylacrylamide (DEA) monomer to improve the swelling behavior and the total absorbing water. These copolymer hydrogels were prepared by changing the initial DEA/IA molar ratio and total monomer concentration. The chemical structure of hydrogels was characterized by fourier transform infrared (FTIR) spectroscopy. In comparison with the PDEA hydrogel, the equilibrium swelling ratio (ESR) of the hydrogels increase with the increase of IA content in the feed and the swelling dynamics behaviors of the different composition ratios of the P(DEA-co-IA) hydrogels on the different temperatures was investigated in detail.

The effect of ligand symmetry on the ratiometric luminescence characteristics of lanthanides

2018 ◽  
Vol 47 (19) ◽  
pp. 6779-6786 ◽  
Author(s):  
Yoshinori Okayasu ◽  
Hajime Kamebuchi ◽  
Junpei Yuasa
Keyword(s):  
Temperature Changes ◽  
Spectral Changes ◽  
Response To Temperature ◽  
Luminescence Characteristics

Nona-coordinated europium(iii) complexes incorporating unsymmetrical β-diketonate ligands exhibit distinctive ratiometric spectral changes within the extremely narrow f–f transition bands in response to temperature changes over the range from 253 to 323 K.

Synthesis, structure and film-forming properties of poly(butyl methacrylate)-poly(methacrylic acid) core-shell latex

Polymer ◽  
1994 ◽  
Vol 35 (8) ◽  
pp. 1779-1786 ◽  
Author(s):  
Haeng-Boo Kim ◽  
Yongcai Wang ◽  
Mitchell A. Winnik
Keyword(s):  
Methacrylic Acid ◽  
Butyl Methacrylate ◽  
Core Shell ◽  
Film Forming

Response of Two Arctic Amphipods, Gammarus zaddachi and Boeckosimus (Onisimus) affinis, to Variations in Temperature and Salinity

1975 ◽  
Vol 32 (12) ◽  
pp. 2564-2568 ◽  
Author(s):  
M. Busdosh ◽  
Ronald M. Atlas
Keyword(s):  
Respiration Rate ◽  
Ecological Distribution ◽  
Temperature Changes ◽  
Gammarus Zaddachi ◽  
Wide Range ◽  
Abrupt Changes ◽  
Response To Temperature

Two arctic amphipods were found to be capable of tolerating a wide range of temperatures and salinities. They were tolerant to both abrupt changes, as would occur in crossing a thermocline, and to gradual changes, as would occur seasonally.Gammarus zaddachi could survive lower salinities and higher temperatures than Boeckosimus (Onisimus) affinis. Salinity had a statistically significant effect on rates of respiration for both organisms, but only Gammarus zaddachi showed significant changes in respiration rate in response to temperature changes. The ecological distribution of these amphipods appears to be in part determined by their ability to tolerate fluctuations in salinity and temperature.

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