Tubular membranes extended between monolayer cells, from solid spheroids, and from clustered hollow spheroids in Ishikawa endometrial cell cultures can carry chromatin granules and mitonucleons

10.7287/peerj.preprints.27895v1 ◽

2019 ◽

Author(s):

Honoree Fleming

Keyword(s):

Self Assembly ◽

Mammalian Cells ◽

Cell Formation ◽

Subcellular Organelle ◽

Pass Through ◽

Solid Cell ◽

First Time ◽

Tubular Membranes ◽

Colony Fragment ◽

Endometrial Epithelial Cells

Membrane tubular extensions, recently recognized an important communication element in mammalian cells are demonstrated to form in Ishikawa endometrial epithelial cells growing in monolayers, and to extend from solid spheroids and from clustered hollow spheroids. Two kinds of chromatin cargoes travel through these tubules. Chromatin granules can pass through an endometrial tubule bridge extending from one monolayer fragment to another. The passage of granules over time from one of the fragments appears to support the self-assembly of nuclei in the other colony fragment. Similarly, in a process detected by observing an open-ended membrane tubule extending from a solid cell spheroid, a nucleus was observed to form over a period of 3 hours. Indications are that chromatin granules such as those observed in the amitotic processes of epithelial dome cell formation and of hollow spheroid cell formation are contributing to the build up of nuclei. Mitonucleons, a transient subcellular organelle consisting of fused mitochondria intimately associated with aggregated chromatin are also observed to pass through tubular membrane extensions. Multiple membrane extensions can be shown to to extend from clusters of unicellular polyploid hollow spheroids whose formation is described for the first time in this paper.

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Programmable in vitro Co-Encapsidation of Guest Proteins Inside Protein Nanocages

10.26434/chemrxiv.5844393 ◽

2018 ◽

Author(s):

Noor H. Dashti ◽

Rufika S. Abidin ◽

Frank Sainsbury

Keyword(s):

Self Assembly ◽

Mammalian Cells ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Super Resolution ◽

Cell Engineering ◽

Particle Analysis ◽

Protein Cages

Bioinspired self-sorting and self-assembling systems using engineered versions of natural protein cages have been developed for biocatalysis and therapeutic delivery. The packaging and intracellular delivery of guest proteins is of particular interest for both in vitro and in vivo cell engineering. However, there is a lack of platforms in bionanotechnology that combine programmable guest protein encapsidation with efficient intracellular uptake. We report a minimal peptide anchor for in vivo self-sorting of cargo-linked capsomeres of the Murine polyomavirus (MPyV) major coat protein that enables controlled encapsidation of guest proteins by in vitro self-assembly. Using Förster resonance energy transfer (FRET) we demonstrate the flexibility in this system to support co-encapsidation of multiple proteins. Complementing these ensemble measurements with single particle analysis by super-resolution microscopy shows that the stochastic nature of co-encapsidation is an overriding principle. This has implications for the design and deployment of both native and engineered self-sorting encapsulation systems and for the assembly of infectious virions. Taking advantage of the encoded affinity for sialic acids ubiquitously displayed on the surface of mammalian cells, we demonstrate the ability of self-assembled MPyV virus-like particles to mediate efficient delivery of guest proteins to the cytosol of primary human cells. This platform for programmable co-encapsidation and efficient cytosolic delivery of complementary biomolecules therefore has enormous potential in cell engineering.

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Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

10.26434/chemrxiv.5972173.v1 ◽

2018 ◽

Author(s):

Nidhi Gour ◽

Bharti Koshti ◽

Chandra Kanth P. ◽

Dhruvi Shah ◽

Vivek Shinh Kshatriya ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Self Assembly ◽

Aromatic Amino Acids ◽

Neutral Condition ◽

Single Amino Acid ◽

Binding Assays ◽

Human Neuroblastoma ◽

Cytotoxicity Assays ◽

First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

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Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

10.26434/chemrxiv.7098695 ◽

2018 ◽

Author(s):

Elaine A. Kelly ◽

Judith E. Houston ◽

Rachel Evans

Keyword(s):

Real Time ◽

Absorption Spectroscopy ◽

Self Assembly ◽

Uv Light ◽

Wormlike Micelles ◽

Tetraethylene Glycol ◽

Light Illumination ◽

First Time ◽

Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such asdrug delivery and micellar catalysis. Currently, their behaviour in the equilibrium cis-and trans-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C8AzoOC8E4) using small-angle neutron scattering (SANS). We show that the incorporation of in-situUV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C8AzoOC8E4could switch between wormlike micelles (transnative state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked in-situthrough combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

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Autophagy Deficiency by Atg4B Loss Leads to Metabolomic Alterations in Mice

Metabolites ◽

10.3390/metabo11080481 ◽

2021 ◽

Vol 11 (8) ◽

pp. 481

Author(s):

Gemma G. Martínez-García ◽

Raúl F. Pérez ◽

Álvaro F. Fernández ◽

Sylvere Durand ◽

Guido Kroemer ◽

...

Keyword(s):

Skeletal Muscle ◽

Amino Acids ◽

Mammalian Cells ◽

Tissue Homeostasis ◽

In Vivo Studies ◽

Protective Mechanism ◽

Cardiac Damage ◽

Wide Range ◽

First Time

Autophagy is an essential protective mechanism that allows mammalian cells to cope with a variety of stressors and contributes to maintaining cellular and tissue homeostasis. Due to these crucial roles and also to the fact that autophagy malfunction has been described in a wide range of pathologies, an increasing number of in vivo studies involving animal models targeting autophagy genes have been developed. In mammals, total autophagy inactivation is lethal, and constitutive knockout models lacking effectors of this route are not viable, which has hindered so far the analysis of the consequences of a systemic autophagy decline. Here, we take advantage of atg4b−/− mice, an autophagy-deficient model with only partial disruption of the process, to assess the effects of systemic reduction of autophagy on the metabolome. We describe for the first time the metabolic footprint of systemic autophagy decline, showing that impaired autophagy results in highly tissue-dependent alterations that are more accentuated in the skeletal muscle and plasma. These changes, which include changes in the levels of amino-acids, lipids, or nucleosides, sometimes resemble those that are frequently described in conditions like aging, obesity, or cardiac damage. We also discuss different hypotheses on how impaired autophagy may affect the metabolism of several tissues in mammals.

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Interactions between an Associative Amphiphilic Block Polyelectrolyte and Surfactants in Water: Effect of Charge Type on Solution Properties and Aggregation

Polymers ◽

10.3390/polym13111729 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1729

Author(s):

Patrizio Raffa

Keyword(s):

Surface Tension ◽

Self Assembly ◽

Interaction Model ◽

Industrial Applications ◽

Molecular Organization ◽

Different Types ◽

Solution Rheology ◽

Interesting Class ◽

First Time

The study of interactions between polyelectrolytes (PE) and surfactants is of great interest for both fundamental and applied research. These mixtures can represent, for example, models of self-assembly and molecular organization in biological systems, but they are also relevant in industrial applications. Amphiphilic block polyelectrolytes represent an interesting class of PE, but their interactions with surfactants have not been extensively explored so far, most studies being restricted to non-associating PE. In this work, interactions between an anionic amphiphilic triblock polyelectrolyte and different types of surfactants bearing respectively negative, positive and no charge, are investigated via surface tension and solution rheology measurements for the first time. It is evidenced that the surfactants have different effects on viscosity and surface tension, depending on their charge type. Micellization of the surfactant is affected by the presence of the polymer in all cases; shear viscosity of polymer solutions decreases in presence of the same charge or nonionic surfactants, while the opposite charge surfactant causes precipitation. This study highlights the importance of the charge type, and the role of the associating hydrophobic block in the PE structure, on the solution behavior of the mixtures. Moreover, a possible interaction model is proposed, based on the obtained data.

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Taming nitroformate through encapsulation with nitrogen-rich hydrogen-bonded organic frameworks

Nature Communications ◽

10.1038/s41467-021-22475-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jichuan Zhang ◽

Yongan Feng ◽

Richard J. Staples ◽

Jiaheng Zhang ◽

Jean’ne M. Shreeve

Keyword(s):

Thermal Stability ◽

Hydrogen Bonds ◽

Self Assembly ◽

Energetic Materials ◽

Decomposition Temperature ◽

High Oxygen Content ◽

The Poor ◽

Simple Preparation ◽

First Time ◽

Hydrogen Bonded

AbstractOwing to its simple preparation and high oxygen content, nitroformate [−C(NO2)3, NF] is an extremely attractive oxidant component for propellants and explosives. However, the poor thermostability of NF-based derivatives has been an unconquerable barrier for more than 150 years, thus hindering its application. In this study, the first example of a nitrogen-rich hydrogen-bonded organic framework (HOF-NF) is designed and constructed through self-assembly in energetic materials, in which NF anions are trapped in pores of the resulting framework via the dual force of ionic and hydrogen bonds from the strengthened framework. These factors lead to the decomposition temperature of the resulting HOF-NF moiety being 200 °C, which exceeds the challenge of thermal stability over 180 °C for the first time among NF-based compounds. A large number of NF-based compounds with high stabilities and excellent properties can be designed and synthesized on the basis of this work.

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Sol–gel synthesis of 2-dimensional TiO2: self-assembly of Ti–oxoalkoxy–acetate complexes by carboxylate ligand directed condensation

Faraday Discussions ◽

10.1039/c9fd00108e ◽

2021 ◽

Cited By ~ 1

Author(s):

Ruohong Sui ◽

Connor E. Deering ◽

Rohen Prinsloo ◽

Christopher B. Lavery ◽

Nancy Chou ◽

...

Keyword(s):

Self Assembly ◽

Sol Gel ◽

Carboxylate Ligand ◽

Sol Gel Synthesis ◽

First Time

2-Dimensional TiO2 is synthesized for the first time by a sol–gel self-assembly of Ti–oxoalkoxy–acetate complexes.

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Synthesis and self-assembly behaviour of poly(Nα-Boc-l-tryptophan)-block-poly(ethylene glycol)-block-poly(Nα-Boc-l-tryptophan)

RSC Advances ◽

10.1039/c6ra03718f ◽

2016 ◽

Vol 6 (29) ◽

pp. 24142-24153

Author(s):

Andreea S. Voda ◽

Kevin Magniez ◽

Nisa V. Salim ◽

Cynthia Wong ◽

Qipeng Guo

Keyword(s):

Drug Delivery ◽

Ethylene Glycol ◽

Self Assembly ◽

Triblock Copolymers ◽

Potential Drug ◽

Poly Ethylene Glycol ◽

Drug Delivery Applications ◽

Poly Ethylene ◽

First Time

We report for the first time the use of Nα-Boc-l-tryptophan for the synthesis of amphiphilic BAB triblock copolymers for potential drug delivery applications.

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Self-assembly synthesis of nitrogen-doped mesoporous carbons used as high-performance electrode materials in lithium-ion batteries and supercapacitors

New Journal of Chemistry ◽

10.1039/c7nj02532g ◽

2017 ◽

Vol 41 (21) ◽

pp. 12901-12909 ◽

Cited By ~ 11

Author(s):

Chunfeng Shao ◽

Ziqiang Wang ◽

Errui Wang ◽

Shujun Qiu ◽

Hailiang Chu ◽

...

Keyword(s):

Electrochemical Performance ◽

Lithium Ion Batteries ◽

Self Assembly ◽

High Performance ◽

Electrode Materials ◽

Lithium Ion ◽

Mesoporous Carbons ◽

Nitrogen Doped ◽

First Time ◽

Enhanced Electrochemical Performance

Guanine was, for the first time, used as a nitrogen source during the synthesis of nitrogen-doped porous carbons (NMCs) with enhanced electrochemical performance.

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