Morphological changes in the self-assembly of a radial oligo-phenylene ethynylene amphiphilic system

2008 ◽  
pp. 6567 ◽  
Author(s):  
Gustavo Fernández ◽  
Fátima García ◽  
Luis Sánchez
Keyword(s):  
Self Assembly ◽  
Morphological Changes ◽  
The Self ◽  
Phenylene Ethynylene

Self-assembly of chiral oligo(methylene-p-phenylene-ethynylene)s into vesicle-like particles independent of hydrophobicity/hydrophilicity of side chains and solvents

Soft Matter ◽  
2021 ◽  
Author(s):  
Zhiqiang Zhao ◽  
Zheng Bian ◽  
Yu Chen ◽  
Chuanqing Kang ◽  
Lianxun Gao ◽  
...  
Keyword(s):  
Self Assembly ◽  
Molecular Design ◽  
The Self ◽  
Side Chains ◽  
Phenylene Ethynylene

Chiral oligo(methylene-p-phenyleneethynylene)s can form vesicular assemblies no matter whether side chains and solvents are hydrophilic or hydrophobic. The self-assembly processes are highly independent of molecular design and chemical environments.

scholarly journals Application of Mesoscale Simulation to Explore the pH Response of Eudragit S100 Used as the Novel Colon-Targeted Powder of Pulsatilla Saponin D

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mingcheng Gong ◽  
Zhenhua Chen ◽  
Liangliang Zhou ◽  
Feng Gao ◽  
Jianxin Cheng ◽  
...  
Keyword(s):  
Self Assembly ◽  
Morphological Changes ◽  
Drug Carrier ◽  
Dissipative Particle Dynamics ◽  
Ph Sensitive ◽  
The Self ◽  
Coarse Grained ◽  
Release Mechanism ◽  
Eudragit S100 ◽  
Ph Conditions

As a pH-sensitive nanomaterial, Eudragit S100 has good colon targeting. However, little research has been carried out on its mesoscopic scale. In this paper, the self-assembly behavior of Pulsatilla saponins D (PSD) and Eudragit S100, as well as the loading and release mechanism of PSD, was investigated via computer simulations. The effects of the self-assembly characteristics of PSD and Eudragit S100 in the dry powder state on the drug-carrier ratio were explored by the coarse-grained molecular dynamics (CGMD) method. According to the pH-responsive feature of Eudragit S100, the drug protection under gastric pH conditions and release in colonic pH conditions were simulated through the dissipative particle dynamics (DPD) method, which has provided insights into the microscopic morphological changes in the pH-sensitive drug delivery systems.

Two-dimensional (2D) self-assembly of oligo(phenylene-ethynylene) molecules and their triangular platinum(ii) diimine complexes studied using STM

2017 ◽  
Vol 19 (46) ◽  
pp. 31284-31289 ◽  
Author(s):  
Siqi Zhang ◽  
Yanfang Geng ◽  
Yuanpeng Fan ◽  
Wubiao Duan ◽  
Ke Deng ◽  
...  
Keyword(s):  
Self Assembly ◽  
Scanning Tunneling Microscope ◽  
The Self ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Phenylene Ethynylene ◽  
Tunneling Microscope ◽  
Diimine Complexes

The self-assembly of a series of cyclic oligo(phenylene-ethynylene) (OPE) molecules and their triangular Pt(ii) diimine complexes were studied using scanning tunneling microscope (STM).

Self-Assembly of Phenylene Ethynylene Diazonium Salts on Metal Surfaces as Potential Molecular Wires

2000 ◽  
Vol 660 ◽  
Author(s):  
Dmitry V. Kosynkin ◽  
Jiping Yang ◽  
James M. Tour
Keyword(s):  
Self Assembly ◽  
Metal Surfaces ◽  
Molecular Wires ◽  
The Self ◽  
Acetonitrile Solution ◽  
Diazonium Salts ◽  
Phenylene Ethynylene ◽  
Aromatic Rings ◽  
Solvent Formation ◽  
Assembly Rate

ABSTRACTA series of substituted phenylene ethynylene diazonium salts were prepared from the corresponding anilines by the action of nitrosonium tetrafluoroborate in sulfolane-acetonitrile solvent. Formation of self-assembled layers of the diazonium salts in acetonitrile solution was demonstrated on Au, Cu and Pt surfaces. The self-assembly rate of the diazonium salts was found to be markedly dependent on the electron withdrawing character of the substituents attached to the aromatic rings.

scholarly journals Controlled Morphological Changes in Self-Assembled Structures Formed by Fmoc Variants of Threonine and Serine

2021 ◽  
Author(s):  
Vivekshinh Kshtriya ◽  
Bharti Koshti ◽  
Nidhi Gour
Keyword(s):  
Self Assembly ◽  
Room Temperature ◽  
Morphological Changes ◽  
The Self ◽  
Temperature Conditions ◽  
Morphological Transitions ◽  
Concentration Changes ◽  
Higher Temperature ◽  
Self Assembled ◽  
First Time

<p>We report for the very first time the self-assembly of<a> </a>Fmoc variant 2-(9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(tert-butoxy)butanoic acid of threonine (<b>Fmoc-Thr(tbu)-OH</b>) and <a>of serine (</a><b>Fmoc-</b><b>Ser(tbu)-OH</b>. The self-assembled structure formation of Fmoc variants of threonine and serine were examined under varying concentration and temperature conditions..Our studies reveal that the self-assembled structures formed by <b>Fmoc-Thr(tbu)-OH </b>and <b>Fmoc-Ser(tbu)-OH </b>reveal morphological transitions at the supramolecular level as we alter its concentration and temperature. <b>Fmoc-Thr(tbu)-OH </b>self-assembles to sphere at lower concentration which changes to dumb-bell shapes at higher concentration under room temperature conditions. When the solution at lower concentration is heated the spheres changes to rods while the dumb bell shapes at higher concentrations change to elongated dumb-bell-rod like morphologies. <b>Fmoc-Ser(tbu)-OH </b>on<b> </b>the other hand give flower like morphologies at lower concentration which changes to long rods at higher concentration. On heating at higher temperature 70 <sup>ο</sup>C flower-like structures change to small rods while the long rods obtained at higher concentration changes to big flower-like structures. The controlled morphological changes noted in the modified single amino acids is very interesting and pave the way for the design of novel self-assembled architectures for applications in material science and nanotechnology.</p>

scholarly journals Controlled Morphological Changes in Self-Assembled Structures Formed by Fmoc Variants of Threonine and Serine

2021 ◽  
Author(s):  
Vivekshinh Kshtriya ◽  
Bharti Koshti ◽  
Nidhi Gour
Keyword(s):  
Self Assembly ◽  
Room Temperature ◽  
Morphological Changes ◽  
The Self ◽  
Temperature Conditions ◽  
Morphological Transitions ◽  
Concentration Changes ◽  
Higher Temperature ◽  
Self Assembled ◽  
First Time

<p>We report for the very first time the self-assembly of<a> </a>Fmoc variant 2-(9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(tert-butoxy)butanoic acid of threonine (<b>Fmoc-Thr(tbu)-OH</b>) and <a>of serine (</a><b>Fmoc-</b><b>Ser(tbu)-OH</b>. The self-assembled structure formation of Fmoc variants of threonine and serine were examined under varying concentration and temperature conditions..Our studies reveal that the self-assembled structures formed by <b>Fmoc-Thr(tbu)-OH </b>and <b>Fmoc-Ser(tbu)-OH </b>reveal morphological transitions at the supramolecular level as we alter its concentration and temperature. <b>Fmoc-Thr(tbu)-OH </b>self-assembles to sphere at lower concentration which changes to dumb-bell shapes at higher concentration under room temperature conditions. When the solution at lower concentration is heated the spheres changes to rods while the dumb bell shapes at higher concentrations change to elongated dumb-bell-rod like morphologies. <b>Fmoc-Ser(tbu)-OH </b>on<b> </b>the other hand give flower like morphologies at lower concentration which changes to long rods at higher concentration. On heating at higher temperature 70 <sup>ο</sup>C flower-like structures change to small rods while the long rods obtained at higher concentration changes to big flower-like structures. The controlled morphological changes noted in the modified single amino acids is very interesting and pave the way for the design of novel self-assembled architectures for applications in material science and nanotechnology.</p>

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

1992 ◽  
Vol 50 (1) ◽  
pp. 712-713
Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Licheniformis ◽  
Self Assembly ◽  
Gel Electrophoresis ◽  
Culture Supernatant ◽  
Regular Structure ◽  
The Self ◽  
Cellular Distribution ◽  
Structural Protein ◽  
Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

Nanoscale Self-Assembly Using Ion and Electron Beam Techniques: A Rapid Review

MRS Advances ◽  
2020 ◽  
Vol 5 (64) ◽  
pp. 3507-3520
Author(s):  
Chunhui Dai ◽  
Kriti Agarwal ◽  
Jeong-Hyun Cho
Keyword(s):  
Electron Beam ◽  
Self Assembly ◽  
Ion Beam ◽  
Three Dimensional ◽  
The Self ◽  
Stress Generation ◽  
Rapid Review ◽  
High Yield ◽  
3D Nanostructures ◽  
Self Assembled

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.

Bottom-up Evolution from Disks to High-Genus Polymersomes

2018 ◽  
Author(s):  
Claudia Contini ◽  
Russell Pearson ◽  
Linge Wang ◽  
Lea Messager ◽  
Jens Gaitzsch ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Chain Entanglement ◽  
Bottom Up ◽  
New Approach ◽  
High Genus ◽  
Transmission Electron ◽  
Minimal Radius ◽  
Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

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