Self-organizing bioinspired oligothiophene–oligopeptide hybrids

In this minireview, we survey recent advances in the synthesis, characterization, and modeling of new oligothiophene–oligopeptide hybrids capable of forming nanostructured fibrillar aggregates in solution and on solid substrates. Compounds of this class are promising for applications because their self-assembly and stimuli-responsive properties, provided by the peptide moieties combined with the semiconducting properties of the thiophene blocks, can result in novel opportunities for the design of advanced smart materials. These bio-inspired molecular hybrids are experimentally shown to form stable fibrils as visualized by AFM and TEM. While the experimental evidence alone is not sufficient to reveal the exact molecular organization of the fibrils, theoretical approaches based on quantum chemistry calculations and large-scale atomistic molecular dynamics simulations are attempted in an effort to reveal the structure of the fibrils at the nanoscale. Based on the combined theoretical and experimental analysis, the most likely models of fibril formation and aggregation are suggested.

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Luminescent Supramolecular Nano- or Microstructures Formed in Aqueous Media by Amphiphile-Noble Metal Complexes

Journal of Nanomaterials ◽

10.1155/2020/5395048 ◽

2020 ◽

Vol 2020 ◽

pp. 1-24 ◽

Cited By ~ 1

Author(s):

Carmen Cretu ◽

Loredana Maiuolo ◽

Domenico Lombardo ◽

Elisabeta I. Szerb ◽

Pietro Calandra

Keyword(s):

Noble Metal ◽

Smart Materials ◽

Self Assembly ◽

Noble Metals ◽

Photophysical Properties ◽

Aqueous Media ◽

Molecular Architecture ◽

Stimuli Responsive ◽

Panoramic View ◽

Amphiphilic Molecules

The involvement of metal ions within the self-assembly spontaneously occurring in surfactant-based systems gives additional and interesting features. The electronic states of the metal, together with the bonds that can be established with the organic amphiphilic counterpart, are the factors triggering new photophysical properties. Moreover, the availability of stimuli-responsive supramolecular amphiphile assemblies, able to disassemble in a back-process, provides reversible switching particularly useful in novel approaches and applications giving rise to truly smart materials. In particular, small amphiphiles with an inner distribution, within their molecular architecture, of various polar and apolar functional groups, can give a wide variety of interactions and therefore enriched self-assemblies. If it is joined with the opportune presence and localization of noble metals, whose chemical and photophysical properties are undiscussed, then very interesting materials can be obtained. In this minireview, the basic concepts on self-assembly of small amphiphilic molecules with noble metals are shown with particular reference to the photophysical properties aiming at furnishing to the reader a panoramic view of these exciting problematics. In this respect, the following will be shown: (i) the principles of self-assembly of amphiphiles that involve noble metals, (ii) examples of amphiphiles and amphiphile-noble metal systems as representatives of systems with enhanced photophysical properties, and (iii) final comments and perspectives with some examples of modern applications.

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Self-assembly of dual-responsive amphiphilic POEGMA-b-P4VP-b-POEGMA triblock copolymers: Effect of temperature, pH, and complexation with Cu2+

Polymer Chemistry ◽

10.1039/d1py00716e ◽

2021 ◽

Author(s):

Daniela M. Zanata ◽

Maria Isabel Felisberti

Keyword(s):

Smart Materials ◽

Self Assembly ◽

Triblock Copolymers ◽

Critical Micellar Concentration ◽

Effect Of Temperature ◽

Important Class ◽

Stimuli Responsive ◽

Dual Responsive

Amphiphilic and stimuli-responsive triblock copolymers are an important class of smart materials due to their low critical micellar concentration in solution and capacity of self-assembly into different structures depending on...

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Ephemeral protein binding to DNA shapes stable nuclear bodies and chromatin domains

10.1101/065664 ◽

2016 ◽

Author(s):

C. A. Brackley ◽

B. Liebchen ◽

D. Michieletto ◽

F. Mouvet ◽

P. R. Cook ◽

...

Keyword(s):

Dna Binding ◽

Self Assembly ◽

Brownian Dynamics ◽

Large Scale ◽

Nuclear Bodies ◽

Underlying Structure ◽

Post Translational Modification ◽

Equilibrium Process ◽

Dynamics Simulations ◽

Brownian Dynamics Simulations

AbstractFluorescence microscopy reveals that the contents of many (membrane-free) nuclear “bodies” exchange rapidly with the soluble pool whilst the underlying structure persists; such observations await a satisfactory biophysical explanation. To shed light on this, we perform large-scale Brownian dynamics simulations of a chromatin fiber interacting with an ensemble of (multivalent) DNA-binding proteins; these proteins switch between two states – active (binding) and inactive (non-binding). This system provides a model for any DNA-binding protein that can be modified post-translationally to change its affinity for DNA (e.g., like the phosphorylation of a transcription factor). Due to this out-of-equilibrium process, proteins spontaneously assemble into clusters of self-limiting size, as individual proteins in a cluster exchange with the soluble pool with kinetics like those seen in photo-bleaching experiments. This behavior contrasts sharply with that exhibited by “equilibrium”, or non-switching, proteins that exist only in the binding state; when these bind to DNA non-specifically, they form clusters that grow indefinitely in size. Our results point to post-translational modification of chromatin-bridging proteins as a generic mechanism driving the self-assembly of highly dynamic, non-equilibrium, protein clusters with the properties of nuclear bodies. Such active modification also reshapes intra-chromatin contacts to give networks resembling those seen in topologically-associating domains, as switching markedly favors local (short-range) contacts over distant ones.

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Atomistic simulation studies of ionic cyanine dyes: self-assembly and aggregate formation in aqueous solution

Physical Chemistry Chemical Physics ◽

10.1039/d0cp06205g ◽

2021 ◽

Author(s):

Gary Yu ◽

Martin Walker ◽

Mark Richard Wilson

Keyword(s):

Molecular Dynamics ◽

Aqueous Solution ◽

Liquid Crystals ◽

Self Assembly ◽

Atomistic Simulation ◽

Large Scale ◽

Cyanine Dyes ◽

Simulation Studies ◽

Aggregate Formation ◽

Dynamics Simulations

Cyanine dyes are known to form large-scale aggregates of various morphologies via spontaneous self-assembly in aqueous solution, akin to chromonic liquid crystals. Atomistic molecular dynamics simulations have been performed on...

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Carbocycle-Based Organogelators: Influence of Chirality and Structural Features on Their Supramolecular Arrangements and Properties

Gels ◽

10.3390/gels7020054 ◽

2021 ◽

Vol 7 (2) ◽

pp. 54

Author(s):

Rosa M. Ortuño

Keyword(s):

Smart Materials ◽

Self Assembly ◽

Rational Design ◽

Structural Features ◽

Stimuli Responsive ◽

Polycyclic Compounds ◽

Relative Configuration ◽

Responsive Materials ◽

Self Assembling ◽

Donor Acceptor

The rational design and engineer of organogel-based smart materials and stimuli-responsive materials with tuned properties requires the control of the non-covalent forces driving the hierarchical self-assembly. Chirality, as well as cis/trans relative configuration, also plays a crucial role promoting the morphology and characteristics of the aggregates. Cycloalkane derivatives can provide chiral chemical platforms allowing the incorporation of functional groups and hydrophobic structural units able for a convenient molecular stacking leading to gels. Restriction of the conformational freedom imposed by the ring strain is also a contributing issue that can be modulated by the inclusion of flexible segments. In addition, donor/acceptor moieties can also be incorporated favoring the interactions with light or with charged species. This review offers a perspective on the abilities and properties of carbocycle-based organogelators starting from simple cycloalkane derivatives, which were the key to establish the basis for an effective self-assembling, to sophisticated polycyclic compounds with manifold properties and applications.

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Effect of molecular solvents of varying polarity on the self-assembly of 1-n-dodecyl-3-methylimidazolium octylsulfate ionic liquid

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633618400047 ◽

2018 ◽

Vol 17 (03) ◽

pp. 1840004 ◽

Cited By ~ 3

Author(s):

Utkarsh Kapoor ◽

Jindal K. Shah

Keyword(s):

Ionic Liquid ◽

Self Assembly ◽

Large Scale ◽

Structural Features ◽

Nematic Order ◽

Structure Factors ◽

Dynamics Simulations ◽

Multiple Domains ◽

Molecular Solvents

Large-scale molecular dynamics simulations consisting of more than 88,000–106,000 atoms for approximately 250 ns (including equilibration and production) were conducted to assess the effect of polar, nonpolar and amphiphilic molecular solvents on the nanoscale structuring of 1-[Formula: see text]-dodecyl-3-methylimidazolium [C[Formula: see text]mim] octylsulfate [C8SO4] ionic liquid (IL). Water [H2O], [Formula: see text]-octane [C8H[Formula: see text]] and 1-octanol [C8H[Formula: see text]OH] are employed as examples of polar, nonpolar, and amphiphilic molecules, respectively. The results indicate that each of these molecular solvents modify the nanosegregation behavior of the ionic liquid in a unique way. Water induces a high order of structuring of the ionic liquid as indicated by extremely high nematic order parameter for the system. In addition, the morphology of the neat ionic liquid is transformed from layer-like to that of bilayer-like in which the polar and nonpolar domains alternate. The presence of water also causes the stretching of the nonpolar domain, thus, increasing its size. At the concentration examined in this work, [Formula: see text]-octane is found to be only partially miscible with the ionic liquid. The polar network is maintained; however, the continuous cationic nonpolar domain is split into multiple domains. [Formula: see text]-octane is accommodated in the ionic liquid nonpolar domain. Similarly, the amphiphilicity of 1-octanol leads to an increase in the number of cationic as well as anionic domains. The overall nonpolar domain length, however, remains nearly identical to that found for the pure ionic liquid. Additional characterization of structural features of the three systems is discussed in terms of one-dimensional number densities, nematic order parameters for the overall systems and their components and structure factors.

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Large-scale dissipative particle dynamics simulations of self-assembled amphiphilic systems

Chemical Communications ◽

10.1039/c4cc03096f ◽

2014 ◽

Vol 50 (61) ◽

pp. 8306-8308 ◽

Cited By ~ 22

Author(s):

Xuejin Li ◽

Yu-Hang Tang ◽

Haojun Liang ◽

George Em Karniadakis

Keyword(s):

Self Assembly ◽

Large Scale ◽

Dissipative Particle Dynamics ◽

Particle Dynamics ◽

The Self ◽

Amphiphilic Molecules ◽

Self Assembled ◽

Dynamics Simulations ◽

Confined Environment

GPU-accelerated dissipative particle dynamics has been explored to probe the self-assembly of amphiphilic molecules in a soft confined environment.

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Responsive Nanostructured Polymer Particles

Polymers ◽

10.3390/polym13020273 ◽

2021 ◽

Vol 13 (2) ◽

pp. 273

Author(s):

Kang Hee Ku

Keyword(s):

Smart Materials ◽

Self Assembly ◽

Research Field ◽

Stimuli Responsive ◽

Polymer Particles ◽

Future Directions ◽

Nanostructured Polymer ◽

Polymer Architectures ◽

Shape Controlled ◽

Shape Tuning

Responsive polymer particles with switchable properties are of great importance for designing smart materials in various applications. Recently, the self-assembly of block copolymers (BCPs) and polymer blends within evaporative emulsions has led to advances in the shape-controlled synthesis of polymer particles. Despite extensive recent progress on BCP particles, the responsive shape tuning of BCP particles and their applications have received little attention. This review provides a brief overview of recent approaches to developing non-spherical polymer particles from soft evaporative emulsions based on the physical principles affecting both particle shape and inner structure. Special attention is paid to the stimuli-responsive, shape-changing nanostructured polymer particles, i.e., design of polymers and surfactant pairs, detailed experimental results, and their applications, including the state-of-the-art progress in this field. Finally, the perspectives on current challenges and future directions in this research field are presented, including the development of surfactants with higher reversibility to multiple stimuli and polymers with unique structural functionality, and diversification of polymer architectures.

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