scholarly journals Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies

2021 ◽  
Vol 17 ◽  
pp. 166-185
Author(s):  
Alexander Zika ◽  
Franziska Gröhn
Keyword(s):  
Self Assembly ◽  
Supramolecular Assembly ◽  
Building Blocks ◽  
Titration Calorimetry ◽  
Ph Responsive ◽  
Interaction Forces ◽  
Vis Spectroscopy ◽  
The Stability ◽  
State Dissociation ◽  
Naphthol Derivatives

Light- and pH-responsive nano-assemblies with switchable size and structure are formed by the association of a photoacid, anthocyanidin, and a linear polyelectrolyte in aqueous solution. Specifically, anionic disulfonated naphthol derivatives, neutral hydroxyflavylium, and cationic poly(allylamine) are used as building blocks for the ternary electrostatic self-assembly, forming well-defined supramolecular assemblies with tunable sizes of 50 to 500 nm. Due to the network of possible chemical reactions for the anthocyanidin and the excited-state dissociation of the photoacid upon irradiation, different ways to alter the ternary system through external triggering are accessible. The structure and trigger effects can be controlled through the component ratios of the samples. Dynamic and static light scattering (DLS, SLS) and ζ-potential measurements were applied to study the size and the stability of the particles, and information on the molecular structure was gained by UV–vis spectroscopy. Isothermal titration calorimetry (ITC) provided information on the thermodynamics and interaction forces in the supramolecular assembly formation.

scholarly journals Photoresponsive Photoacid-Macroion Nano-Assemblies

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1746
Author(s):  
Alexander Zika ◽  
Sarah Bernhardt ◽  
Franziska Gröhn
Keyword(s):  
Self Assembly ◽  
Electrostatic Interactions ◽  
Building Blocks ◽  
Charge Ratio ◽  
Hydroxyl Group ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Stability ◽  
Nanoscale Aggregates ◽  
State Dissociation

In this study, light-responsive nano-assemblies with light-switchable size based on photoacids are presented. Anionic disulfonated napthol derivates and cationic dendrimer macroions are used as building blocks for electrostatic self-assembly. Nanoparticles are already formed under the exclusion of light as a result of electrostatic interactions. Upon photoexcitation, an excited-state dissociation of the photoacidic hydroxyl group takes place, which leads to a more highly charged linker molecule and, subsequently, to a change in size and structure of the nano-assemblies. The effects of the charge ratio and the concentration on the stability have been examined with absorption spectroscopy and ζ-potential measurements. The influence of the chemical structure of three isomeric photoacids on the size and shape of the nanoscale aggregates has been studied by dynamic light scattering and atomic force microscopy, revealing a direct correlation of the strength of the photoacid with the changes of the assemblies upon irradiation.

scholarly journals Multivalent Lactose–Ferrocene Conjugates Based on Poly (Amido Amine) Dendrimers and Gold Nanoparticles as Electrochemical Probes for Sensing Galectin-3

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 203 ◽  
Author(s):  
Manuel C. Martos-Maldonado ◽  
Indalecio Quesada-Soriano ◽  
Luis García-Fuentes ◽  
Antonio Vargas-Berenguel
Keyword(s):  
Gold Nanoparticles ◽  
Surface Modification ◽  
Cardiac Remodeling ◽  
Building Blocks ◽  
Differential Pulse ◽  
Pamam Dendrimers ◽  
Titration Calorimetry ◽  
Vis Spectroscopy ◽  
Galectin 3 ◽  
Pulse Voltammetry

Galectin-3 is considered a cancer biomarker and bioindicator of fibrosis and cardiac remodeling and, therefore, it is desirable to develop convenient methods for its detection. Herein, an approach based on the development of multivalent electrochemical probes with high galectin-3 sensing abilities is reported. The probes consist of multivalent presentations of lactose–ferrocene conjugates scaffolded on poly (amido amine) (PAMAM) dendrimers and gold nanoparticles. Such multivalent lactose–ferrocene conjugates are synthesized by coupling of azidomethyl ferrocene–lactose building blocks on alkyne-functionalized PAMAM, for the case of the glycodendrimers, and to disulfide-functionalized linkers that are then used for the surface modification of citrate-stabilized gold nanoparticles. The binding and sensing abilities toward galectin-3 of both ferrocene-containing lactose dendrimers and gold nanoparticles have been evaluated by means of isothermal titration calorimetry, UV–vis spectroscopy, and differential pulse voltammetry. The highest sensitivity by electrochemical methods to galectin-3 was shown by lactosylferrocenylated gold nanoparticles, which are able to detect the lectin in nanomolar concentrations.

scholarly journals Chemically coded time-programmed self-assembly

2017 ◽  
Vol 2 (3) ◽  
pp. 274-282 ◽  
Author(s):  
Eszter Tóth-Szeles ◽  
Judit Horváth ◽  
Gábor Holló ◽  
Rózsa Szűcs ◽  
Hideyuki Nakanishi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
The Self ◽  
Ph Responsive ◽  
Clock Reaction

Coupling of a pH clock reaction (activation) with lactone hydrolysis (deactivation) can control and drive the self-assembly of pH-responsive building blocks.

scholarly journals A Supramolecular Assembly of Hemoproteins Formed in a Star-Shaped Structure via Heme–Heme Pocket Interactions

2021 ◽  
Vol 22 (3) ◽  
pp. 1012
Author(s):  
Julian Wong Soon ◽  
Koji Oohora ◽  
Shota Hirayama ◽  
Takashi Hayashi
Keyword(s):  
Supramolecular Assembly ◽  
Building Blocks ◽  
Size Exclusion ◽  
Hydrodynamic Diameter ◽  
Prosthetic Group ◽  
Heme Pocket ◽  
Cytochrome B562 ◽  
Sds Page ◽  
Vis Spectroscopy ◽  
Exclusion Chromatography

Proteins have been used as building blocks to provide various supramolecular structures in efforts to develop nano-biomaterials possessing broad biological functionalities. A series of unique structures have been obtained from the engineering of hemoproteins which contain the iron porphyrin known as heme, as a prosthetic group. This work in developing assembling systems is extended using cytochrome b562, a small electron transfer hemoprotein engineered to include an externally-attached heme moiety. The engineered units, which form a one-dimensional assembly via interprotein heme–heme pocket interactions, are conjugated to an apo-form of hexameric tyrosine-coordinated hemoprotein (apoHTHP) to provide a branching unit promoting the assembly of a star-shaped structure. The incorporation of the heme moiety attached to the protein surface of cytochrome b562 into apoHTHP can be accelerated by elevating the reaction temperature to generate a new assembly. The formation of a new larger assembly structure was confirmed by size exclusion chromatography. The ratio of the heme-containing units in the assemblies was analyzed by UV-Vis spectroscopy and the population of protein units estimated from SDS PAGE suggests the presence of plausible star-shaped structures, which are supported by hydrodynamic diameter data obtained by dynamic light scattering.

UV and pH-responsive supra-amphiphiles driven by combined interactions for controlled self-assembly behaviors

Soft Matter ◽  
2018 ◽  
Vol 14 (11) ◽  
pp. 2112-2117 ◽  
Author(s):  
Shangyang Li ◽  
Aiyou Hao ◽  
Jian Shen ◽  
Ningzhao Shang ◽  
Chun Wang
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Ph Responsive ◽  
Stimulus Properties ◽  
Multiple Stimulus

In order to fabricate a novel supra-amphiphile with multiple stimulus properties, we developed the strategy of introducing a bi-functional linker to bridge the hydrophilic and hydrophobic building blocks together, by utilizing more than one kind of interaction.

Folding induced supramolecular assembly into pH-responsive nanorods with a protein repellent shell

2018 ◽  
Vol 54 (4) ◽  
pp. 401-404 ◽  
Author(s):  
R. Otter ◽  
K. Klinker ◽  
D. Spitzer ◽  
M. Schinnerer ◽  
M. Barz ◽  
...  
Keyword(s):  
Self Assembly ◽  
Supramolecular Assembly ◽  
The Self ◽  
Core Shell ◽  
Ph Responsive ◽  
Peptide Conjugates ◽  
Β Sheets

ABA′ triblock peptide–polysarcosine–peptide conjugates fold into antiparallel β-sheets, which promotes the self-assembly into polysarcosine-shielded core–shell nanorods with protein repellent properties.

scholarly journals Multivalent Lactose–Ferrocene Conjugates Based on Poly(Amido Amine) Dendrimers and Gold Nanoparticles as Electrochemical Probes for Sensing Galectin-3

2020 ◽  
Author(s):  
Manuel C. Martos-Maldonado ◽  
Indalecio Quesada-Soriano ◽  
Luis García-Fuentes ◽  
Antonio Vargas-Berenguel
Keyword(s):  
Gold Nanoparticles ◽  
Surface Modification ◽  
Cardiac Remodeling ◽  
Building Blocks ◽  
Differential Pulse ◽  
Pamam Dendrimers ◽  
Titration Calorimetry ◽  
Vis Spectroscopy ◽  
Galectin 3 ◽  
Pulse Voltammetry

Galectin-3 is considered a cancer biomarker and bioindicator of fibrosis and cardiac remodeling, and, therefore, it is desirable to develop convenient methods for its detection. Herein, an approach based on the development of multivalent electrochemical probes with high galectin-3 sensing abilities is reported. The probes consist of multivalent presentations of lactose–ferrocene conjugates scaffolded on poly(amido amine) (PAMAM) dendrimers and gold nanoparticles. Such multivalent lactose–ferrocene conjugates are synthesized by coupling of azidomethylferrocene-lactose building blocks on alkyne-functionalized PAMAM, for the case of the glycodendrimers, and to disulfide‐functionalized linkers that are then used for the surface modification of citrate-stabilized gold nanoparticles. The binding and sensing abilities towards galectin 3 of both ferrocene-containing lactose dendrimers and gold nanoparticles have been evaluated by means of isothermal titration calorimetry, UV-vis spectroscopy, and differential pulse voltammetry. The highest sensitivity by electrochemical methods to galectin-3 was shown by lactosylferrocenylated gold nanoparticles, which are able to detect the lectin in nanomolar concentrations.

scholarly journals Evaluation of the stability of cucurbit[8]uril-based ternary host−guest complexation in physiological environment and the fabrication of a supramolecular theranostic nanomedicine

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Han Wu ◽  
Zuobing Chen ◽  
Shaolong Qi ◽  
Bing Bai ◽  
Jiajun Ye ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Isothermal Titration Calorimetry ◽  
Disease Diagnosis ◽  
Titration Calorimetry ◽  
Resonance Spectroscopy ◽  
Diagnosis And Therapy ◽  
Vis Spectroscopy ◽  
Non Covalent Interactions ◽  
The Stability ◽  
Covalent Interactions

Abstract Background Supramolecular theranostics have exhibited promising potentials in disease diagnosis and therapy by taking advantages of the dynamic and reversible nature of non-covalent interactions. It is extremely important to figure out the stability of the driving forces in physiological environment for the preparation of theranostic systems. Methods The host−guest complexation between cucurbit[8]uril (CB[8]), 4,4′-bipyridinium, and napththyl guest was fully studied using various characterizations, including nuclear magnetic resonance spectroscopy, ultraviolet–visible (UV–vis) spectroscopy, isothermal titration calorimetry (ITC). The association constants of this ternary complex were determined using isothermal titration calorimetry. The stability of the non-covalent interactions and self-assemblies form from this molecular recognition was confirmed by UV–vis spectroscopy and dynamic light scattering (DLS). A supramolecular nanomedicine was constructed on the basis of this 1:1:1 ternary recognition, and its in vitro and in vivo anticancer efficacy were thoroughly evaluated. Positron emission tomography (PET) imaging was used to monitor the delivery and biodistribution of the supramolecular nanomedicine. Results Various experiments confirmed that the ternary complexation between 4,4′-bipyridinium, and napththyl derivative and CB[8] was stable in physiological environment, including phosphate buffered solution and cell culture medium. Supramolecular nanomedicine (SNM@DOX) encapsulating a neutral anticancer drug (doxrubincin, DOX) was prepared based on this molecular recognition that linked the hydrophobic poly(ε-caprolactone) chain and hydrophilic polyethylene glycol segment. The non-covalent interactions guaranteed the stability of SNM@DOX during blood circulation and promoted its tumor accumulation by taking advantage of the enhanced permeability and retention effect, thus greatly improving the anti-tumor efficacy as compared with the free drug. Conclusion Arising from the host-enhanced charge-transfer interactions, the CB[8]-based ternary recognition was stable enough in physiological environment, which was suitable for the fabrication of supramolecular nanotheranostics showing promising potentials in precise cancer diagnosis and therapy. Graphic Abstract

Supramolecular assembly of functional peptide–polymer conjugates

2019 ◽  
Vol 17 (28) ◽  
pp. 6719-6734 ◽  
Author(s):  
Ronja Otter ◽  
Pol Besenius
Keyword(s):  
Self Assembly ◽  
Synthetic Peptide ◽  
Supramolecular Assembly ◽  
Building Blocks ◽  
Polymer Chains ◽  
Supramolecular Polymer ◽  
Polymer Conjugates ◽  
Supramolecular Architectures ◽  
Functional Peptide ◽  
3D Networks

The following review gives an overview about synthetic peptide–polymer conjugates as macromolecular building blocks and their self-assembly into a variety of supramolecular architectures, from supramolecular polymer chains, to anisotropic 1D arrays, 2D layers, and more complex 3D networks.

A regular thymine tetrad and a peculiar supramolecular assembly in the first crystal structure of an all-LNA G-quadruplex

2014 ◽  
Vol 70 (2) ◽  
pp. 362-370 ◽  
Author(s):  
Irene Russo Krauss ◽  
Gary Nigel Parkinson ◽  
Antonello Merlino ◽  
Carlo Andrea Mattia ◽  
Antonio Randazzo ◽  
...  
Keyword(s):  
Self Assembly ◽  
Supramolecular Assembly ◽  
Building Blocks ◽  
Crystallographic Analysis ◽  
Order Structure ◽  
Promising Tool ◽  
G Quadruplex ◽  
Nuclease Resistance ◽  
Diagnostic Applications ◽  
Structural Descriptions

Locked nucleic acids (LNAs) are formed by bicyclic ribonucleotides where the O2′ and C4′ atoms are linked through a methylene bridge and the sugar is blocked in a 3′-endoconformation. They represent a promising tool for therapeutic and diagnostic applications and are characterized by higher thermal stability and nuclease resistance with respect to their natural counterparts. However, structural descriptions of LNA-containing quadruplexes are rather limited, since few NMR models have been reported in the literature. Here, the first crystallographically derived model of an all-LNA-substituted quadruplex-forming sequence 5′-TGGGT-3′ is presented refined at 1.7 Å resolution. This high-resolution crystallographic analysis reveals a regular parallel G-quadruplex arrangement terminating in a well defined thymine tetrad at the 3′-end. The detailed picture of the hydration pattern reveals LNA-specific features in the solvent distribution. Interestingly, two closely packed quadruplexes are present in the asymmetric unit. They face one another with their 3′-ends giving rise to a compact higher-order structure. This new assembly suggests a possible way in which sequential quadruplexes can be disposed in the crowded cell environment. Furthermore, as the formation of ordered structures by molecular self-assembly is an effective strategy to obtain nanostructures, this study could open the way to the design of a new class of LNA-based building blocks for nanotechnology.

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