Self-Assembly and Photophysical Studies of an Unusual Red Colored Dye Which Show Green Fluorescence in Cell Imaging

We report for the very first time self-assembly of a red color dye 7-Amino-6h-anthra[9,1-cd][1,2]thiazol-6-one (AAT),its photophysical properties and its applications in cell imaging.Interestingly, AAT show intense red colour in visible light while it shows the orange colour fluorescence under UV light @312nm.Surprisingly, when this dye was used as cell imaging agent it revealed only green fluorescence inside cells and not red. Hence, the photophysical properties of this dye was very intriguing. Further, when self-assembling properties of this dye was examined it revealed formation of tree like branched structures which appeared red both under green and red filter which was again an unexpected result..Interestingly AAT self-assembly also show morphological transition and the branched tree like structures changes to straight fibres as the solvent is changed from DMSO to THF. Hence, the results of self-assembly and cell imaging were contrary to each other and the photophysical properties of this dye is very unusual as compared to conventional dyes. Our future endeavours willaim to understand this anomalous behaviour in greater details in future through various biophysical assays.

Download Full-text

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.

Download Full-text

Self-assembling behaviour of a modified aromatic amino acid in competitive medium

Soft Matter ◽

10.1039/d0sm00584c ◽

2020 ◽

Vol 16 (28) ◽

pp. 6599-6607 ◽

Cited By ~ 1

Author(s):

Pijush Singh ◽

Souvik Misra ◽

Nayim Sepay ◽

Sanjoy Mondal ◽

Debes Ray ◽

...

Keyword(s):

Amino Acid ◽

Self Assembly ◽

Aromatic Amino Acid ◽

Photophysical Properties ◽

Solvent Mixture ◽

The Self ◽

Solvent Ratio ◽

Self Assembling

The self-assembly and photophysical properties of 4-nitrophenylalanine (4NP) are changed with the alteration of solvent and final self-assembly state of 4NP in competitive solvent mixture and are dictated by the solvent ratio.

Download Full-text

PhotoATRP Induced Self-Assembly (PhotoATR-PISA) Enables Simplified Synthesis of Responsive Polymer Nanoparticles in One-Pot

10.26434/chemrxiv.12988559 ◽

2020 ◽

Author(s):

Ali Shahrokhinia ◽

Randall Scanga ◽

Priyanka Biswas ◽

James Reuther

Keyword(s):

Self Assembly ◽

Glycidyl Methacrylate ◽

Uv Light ◽

Copper Catalyst ◽

Crosslinking Agent ◽

Polymer Nanoparticles ◽

One Pot ◽

Responsive Polymer ◽

Catalyst Systems ◽

First Time

ABSTRACT: Photo-controlled atom transfer radical polymerization (PhotoATRP) was implemented, for the first time, to accomplish polymerization induced self-assembly (PISA) mediated by UV light (λ = 365 nm) using ppm levels (ca. < 20 ppm) of copper catalyst at ambient temperature. Using CuIIBr2/tris(pyridin-2-ylmethyl)amine (TPMA) catalyst systems, PISA was per-formed all in one-pot starting from synthesis of solvophilic poly(oligo(ethylene oxide) methyl ether methacrylate) (POEGMA) blocks to core-crosslinked nanoparticles (NPs) utilizing poly(glycidyl methacrylate) (PGMA) and N,N-cystamine bismethacrylamide (CBMA) as the solvophobic copolymer and crosslinking agent, respectively. Sequential chain-extensions were performed for PGMA demonstrating capabilities for accessing multi-block copolymers with temporal control via switching the UV light on and off. Further, core-crosslinking of PISA nanoparticles was performed via the slow incorporation of the CBMA enabling one-pot crosslinking during the PISA process. Finally, the disulfide installed in the CBMA core-crosslinks allowed for the stimuli-triggered dissociation of nanoparticles using DL-dithiothreitol at acidic pH.

Download Full-text

The Human Body is a Pressurized Self-Assembly Machine

Volume 2: Biomedical and Biotechnology ◽

10.1115/imece2012-86137 ◽

2012 ◽

Author(s):

Brenda K. Krkosska Bayles

Keyword(s):

Blood Pressure ◽

Human Body ◽

Self Assembly ◽

The Novel ◽

Daughter Cells ◽

Self Assembling ◽

Living Tissues ◽

First Time

The novel and self-obtained concept of this paper is that living tissues get help self-assembling by following some mechanical equations. The simple diagnostic act of checking someone’s blood pressure reminds us that the human body is a pressurized object, and blood moving throughout the pressurized body creates flows that are strikingly similar to the movements of fluids in pressurized machines. Self-assembly using two mechanical concepts and their equations is herein demonstrated for the first time to show the separation of healthy daughter cells and the nonseparation of aneuploid cells, and to show monosaccharide and disaccharide movements.

Download Full-text

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

10.26434/chemrxiv.7098695.v1 ◽

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.

Download Full-text

A facile and economical method to synthesize a novel wide gamut fluorescent copolyester with outstanding properties

Polymer Chemistry ◽

10.1039/d1py01222c ◽

2022 ◽

Author(s):

Lele Ma ◽

Jiajian Liu ◽

Chuncheng Li ◽

Yaonan Xiao ◽

Shaohua Wu ◽

...

Keyword(s):

Molecular Weight ◽

High Molecular Weight ◽

Uv Light ◽

Green Fluorescence ◽

Economical Method ◽

First Time

A series of high molecular weight copolyesters PExBTyAm were synthesized by a simple and economical two-step polycondensation method, and for the first time we found that the copolyesters exhibited an green fluorescence under 365 nm UV light.

Download Full-text

Thiophosphopeptides Instantly Targeting Golgi Apparatus and Selectively Killing Cancer Cells

10.1101/2021.02.13.431079 ◽

2021 ◽

Author(s):

Weiyi Tan ◽

Qiuxin Zhang ◽

Jiaqing Wang ◽

Meihui Yi ◽

Hongjian He ◽

...

Keyword(s):

Alkaline Phosphatase ◽

Golgi Apparatus ◽

Oxygen Atom ◽

Cancer Cells ◽

Self Assembly ◽

Disulfide Bonds ◽

Unexpected Result ◽

Subcellular Compartment ◽

Self Assembling ◽

Order Of Magnitude

ABSTRACTGolgi apparatus is emerging as a key signaling hub of cells, but there are few approaches for targeting Golgi and selectively killing cancer cells. Here we show an unexpected result that changing an oxygen atom of the phosphoester bond in phospho-peptides by a sulfur atom enables instantly targeting Golgi apparatus (GA) and selectively killing cancer cells by enzymatic self-assembly. Specifically, conjugating cysteamine S-phosphate to the C-terminal of a self-assembling peptide generates a thiophospho-peptide. Being a substrate of alkaline phosphatase (ALP), the thiophosphopeptide undergoes rapid ALP-catalyzed dephosphorylation to form a thiopeptide that self-assembles. The thiophosphopeptide enters cells via caveolin-mediated endocytosis and macropinocytosis and instantly accumulates in GA because of dephosphorylation and formation of disulfide bonds in Golgi. Moreover, the thiophosphopeptide, targeting Golgi, potently and selectively inhibits cancer cells (e.g., HeLa) with the IC50 (about 3 μM), which is an order of magnitude more potent than that of the parent phosphopeptide. This work, as the first report of thiophospho-peptide for targeting Golgi, illustrates a new molecular platform for designing enzyme responsive molecules that target subcellular compartment for functions.

Download Full-text

Gas barrier enhancement of uncharged apolar polymeric films by self-assembling stratified nano-composite films

RSC Advances ◽

10.1039/c9ra01109a ◽

2019 ◽

Vol 9 (19) ◽

pp. 10938-10947 ◽

Cited By ~ 1

Author(s):

Ali Akbar Motedayen ◽

Mohammadreza Rezaeigolestani ◽

Carole Guillaume ◽

Valérie Guillard ◽

Nathalie Gontard

Keyword(s):

Self Assembly ◽

Hydrophobic Interactions ◽

Composite Films ◽

The Self ◽

Polymeric Films ◽

Assembly Process ◽

Gas Barrier ◽

Nano Composite ◽

Self Assembling ◽

First Time

The gas (O2 and CO2) permeability of an innovative stratified PE–organoclay (LLDPE/OMMT) nano-enabled composite films was studied for the first time and related to the self-assembly process driven by hydrophobic interactions.

Download Full-text

Synthesis and self-assembly studies of a new AIEE probe and its application in sensing amyloid fibrillation

10.26434/chemrxiv.6982895 ◽

2019 ◽

Author(s):

Nidhi Gour ◽

Vivek Shinh Kshtriya ◽

Shradhey Gupta ◽

Ramesh, Singh ◽

Dhawal Patel ◽

...

Keyword(s):

Fluorescence Quenching ◽

Self Assembly ◽

Photophysical Properties ◽

Cost Effective ◽

The Self ◽

Amyloid Fibers ◽

Self Assembling ◽

Amyloid Fibrillation ◽

Morphological Transformations ◽

Novel Scaffold

We report self-assembly and photophysical properties of a new pyridothiazole based aggregation-induced-emission enhancement (AIEE) luminogen 4-(5-methoxy-thiazolo[4,5-b]pyridin-2-yl)benzoic acid (PTC1) and its application for the sensitive detection and monitoring of amyloid fibrillation. The self-assembling properties of the new AIEE probe are extensively studied by AFM and it was noted that as aggregation increases there is enhancement of fluorescence. The fluorescence of PTC1 is quenched upon addition of cupric (Cu2+) ions while the fluorescence is regenerated in the presence of amyloid fibers. AFM studies reveal that PTC1 self associate/aggregate to hairy micelle structures which gets disrupted on the addition of Cu2+ and again reassembles in the presence of amyloid fibers. Hence, the fluorescence quenching and regeneration may be attributed to disaggregation and AIE respectively. Further, a comparative analysis of the performance of PTC1 is done with the conventional ThT which confirms it to be a more sensitive probe for the detection of amyloid both in the presence and absence of Cu2+. Of note, a very simple, facile and cost-effective methodology for the detection of amyloid fibres is presented, wherein fluorescence quenching/enhancement can be visualized under UV without the use of sophisticated instrumentation techniques. To the best of our knowledge and literature survey, this is first report wherein the self-assembling properties of AIEE probe is studied extensively via microscopy and the photophysical properties compared w.r.t to the morphological transformations. The AIEE probe has been designed using an unusual pyridothiazole scaffold unlike the commonly used archetypal AIE scaffolds based on tetraphenylethene (TPE) and hexaphenylsilole (HPS) and hence, the work also has implications in designing new generation AIEE dyes based on novel scaffold reported.

Download Full-text