Synthesis of a Novel Zn-Salphen Building Block and Its Acrylic Terpolymer Counterparts as Tunable Supramolecular Recognition Systems

In this work, we present the synthesis of a novel Zn-Salphen complex containing an allyl group, which was used as building block in the further preparation of a new family of functional terpolymers. These polymers were obtained through radical co-polymerization with methyl metacrylate (MMA) and n-butyl acrylate (nBuA) in different ratios. The supramolecular recognition behavior of each polymer was evaluated via potentiometric measurements against selected anions in aqueous media. Interestingly, this proof of concept study shows that these systems were selective against only fluoride (F−) or both, fluoride and acetate (OAc−), by tailoring the relative content of Zn-Salphen monomer, thus making them a promising starting point for modular design of chemical sensors through straightforward synthetic approaches.

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Robust Helix Formation in a New Family of Oligoureas Based on a Constrained Bicyclic Building Block

Angewandte Chemie ◽

10.1002/ange.201205842 ◽

2012 ◽

Vol 124 (45) ◽

pp. 11429-11432 ◽

Cited By ~ 6

Author(s):

Baptiste Legrand ◽

Christophe André ◽

Emmanuel Wenger ◽

Claude Didierjean ◽

Marie Christine Averlant-Petit ◽

...

Keyword(s):

Building Block ◽

New Family ◽

Helix Formation

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Tailoring gold-conducting polymer nanocomposites for sensors applications: Proof of concept for As(III) sensing in aqueous media

Synthetic Metals ◽

10.1016/j.synthmet.2021.116834 ◽

2021 ◽

Vol 278 ◽

pp. 116834

Author(s):

Kristina Radinović ◽

Jadranka Milikić ◽

Una Stamenović ◽

Vesna Vodnik ◽

Mojca Otoničar ◽

...

Keyword(s):

Polymer Nanocomposites ◽

Conducting Polymer ◽

Aqueous Media ◽

Proof Of Concept

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Examining the Coiling Motion of Soft Actuators Reinforced With Tilted Helix Fibers

Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies ◽

10.1115/smasis2018-8038 ◽

2018 ◽

Cited By ~ 1

Author(s):

Ryan Geer ◽

Suyi Li

Keyword(s):

Longitudinal Axis ◽

Robotic Manipulation ◽

Proof Of Concept ◽

Soft Actuator ◽

Kevlar Fiber ◽

New Family ◽

End Caps ◽

Soft Actuators ◽

Unique Cell ◽

Cell Wall Architecture

This study aims to examine the coiling and uncoiling motion of a soft pneumatic actuator reinforced with tilted helix fibers. Coiling motion can be quite useful for robotic manipulation and locomotion purposes. This research proposes and investigates a novel actuator that is inspired and derived from the unique cell wall architecture in the seed appendage of Stork’s Bill plant (Erodium Gruinum). These plant cells are reinforced by cellulose fibers distributed in a tilted helix pattern — helixes that are tilted at a certain angle with respect to the longitudinal axis of the cell. As a result, the seed appendage can coil and uncoil via a combination of twisting and bending. This paper discusses the design, fabrication, and testing of a soft actuator that can mimic this sophisticated motion. This actuator consists of Kevlar fiber thread wrapped around a silicon rubber body that has the shape of a tube. The tube will be capped at both ends so that it can be pressurized internally to induce motion. Once the design parameter has been chosen, the soft actuator are fabricated by 1) designing and 3D printing molds, 2) tube casting and fiber wrapping, and 3) creating the end caps for pressure sealing. Carefully executing these fabrication steps is essential because any errors could give undesired deformation. Several soft actuators prototypes are fabricated based on different design choices regarding the actuator radius, tube wall thickness, and the number of tilted helix fibers (aka. fiber coverage). Proof-of-concept tests show that these actuator prototypes can indeed exhibit a combined twisting and bending under internal pressurization: all are the necessary receipts to achieve the coiling and uncoiling motion. Result of this paper can pave the way for a new family of soft actuators capable of unprecedented and sophisticated actuation motions, which are particularly appealing for soft robot application.

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Identification of high-efficiency 3′GG gRNA motifs in indexed FASTA files with ngg2

PeerJ Computer Science ◽

10.7717/peerj-cs.33 ◽

2015 ◽

Vol 1 ◽

pp. e33 ◽

Cited By ~ 2

Author(s):

Elisha D. Roberson

Keyword(s):

High Efficiency ◽

Homo Sapiens ◽

Model Organisms ◽

Proof Of Concept ◽

Protein Coding ◽

C Elegans ◽

Protein Coding Genes ◽

Starting Point ◽

Command Line Tool ◽

Reference Genomes

CRISPR/Cas9 is emerging as one of the most-used methods of genome modification in organisms ranging from bacteria to human cells. However, the efficiency of editing varies tremendously site-to-site. A recent report identified a novel motif, called the 3′GG motif, which substantially increases the efficiency of editing at all sites tested inC. elegans. Furthermore, they highlighted that previously published gRNAs with high editing efficiency also had this motif. I designed a Python command-line tool, ngg2, to identify 3′GG gRNA sites from indexed FASTA files. As a proof-of-concept, I screened for these motifs in six model genomes:Saccharomyces cerevisiae,Caenorhabditis elegans,Drosophila melanogaster,Danio rerio,Mus musculus, andHomo sapiens. I also scanned the genomes of pig (Sus scrofa) and African elephant (Loxodonta africana) to demonstrate the utility in non-model organisms. I identified more than 60 million single match 3′GG motifs in these genomes. Greater than 61% of all protein coding genes in the reference genomes had at least one unique 3′GG gRNA site overlapping an exon. In particular, more than 96% of mouse and 93% of human protein coding genes have at least one unique, overlapping 3′GG gRNA. These identified sites can be used as a starting point in gRNA selection, and the ngg2 tool provides an important ability to identify 3′GG editing sites in any species with an available genome sequence.

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Synthetic Approaches to Small- and Medium-Size Aza-Heterocycles in Aqueous Media

Green Synthetic Approaches for Biologically Relevant Heterocycles ◽

10.1016/b978-0-12-800070-0.00007-4 ◽

2015 ◽

pp. 163-184 ◽

Cited By ~ 1

Author(s):

Girija S. Singh ◽

Tumelo H. Tabane

Keyword(s):

Aqueous Media ◽

Medium Size ◽

Synthetic Approaches

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Proof-of-Concept Study of the NOTI Chelating Platform: Preclinical Evaluation of 64Cu-Labeled Mono- and Trimeric c(RGDfK) Conjugates

Molecular Imaging and Biology ◽

10.1007/s11307-020-01530-8 ◽

2020 ◽

Vol 23 (1) ◽

pp. 95-108

Author(s):

Sebastian Martin ◽

Stephan Maus ◽

Tobias Stemler ◽

Florian Rosar ◽

Fadi Khreish ◽

...

Keyword(s):

Ambient Temperature ◽

Building Block ◽

Metal Binding ◽

Small Animal ◽

Building Blocks ◽

Small Animal Pet ◽

Proof Of Concept ◽

Binding Properties ◽

Concept Study ◽

Biodistribution Studies

Abstract Purpose We recently developed a chelating platform based on the macrocycle 1,4,7-triazacyclononane with up to three five-membered azaheterocyclic arms for the preparation of 68Ga- and 64Cu-based radiopharmaceuticals. Based on this platform, the chelator scaffold NOTI-TVA with three additional carboxylic acid groups for bioconjugation was synthesized and characterized. The primary aims of this proof-of-concept study were (1) to evaluate if trimeric radiotracers on the basis of the NOTI-TVA 6 scaffold can be developed, (2) to determine if the additional substituents for bioconjugation at the non-coordinating NH atoms of the imidazole residues of the building block NOTI influence the metal binding properties, and (3) what influence multiple targeting vectors have on the biological performance of the radiotracer. The cyclic RGDfK peptide that specifically binds to the αvß3 integrin receptor was selected as the biological model system. Procedures Two different synthetic routes for the preparation of NOTI-TVA 6 were explored. Three c(RGDfK) peptide residues were conjugated to the NOTI-TVA 6 building block by standard peptide chemistry providing the trimeric bioconjugate NOTI-TVA-c(RGDfK)39. Labeling of 9 with [64Cu]CuCl2 was performed manually at pH 8.2 at ambient temperature. Binding affinities of Cu-8, the Cu2+ complex of the previously described monomer NODIA-Me-c(RGDfK) 8, and the trimer Cu-9 to integrin αvß3 were determined in competitive cell binding experiments in the U-87MG cell line. The pharmacokinetics of both 64Cu-labeled conjugates [64Cu]Cu-8 and [64Cu]Cu-9 were determined by small-animal PET imaging and ex vivo biodistribution studies in mice bearing U-87MG xenografts. Results Depending on the synthetic route, NOTI-TVA 6 was obtained with an overall yield up to 58 %. The bioconjugate 9 was prepared in 41 % yield. Both conjugates [64Cu]Cu-8 and [64Cu]Cu-9 were radiolabeled quantitatively at ambient temperature in high molar activities of Am ~ 20 MBq nmol−1 in less than 5 min. Competitive inhibitory constants IC50 of c(RDGfK) 7, Cu-8, and Cu-9 were determined to be 159.5 ± 1.3 nM, 256.1 ± 2.1 nM, and 99.5 ± 1.1 nM, respectively. In small-animal experiments, both radiotracers specifically delineated αvß3 integrin-positive U-87MG tumors with low uptake in non-target organs and rapid blood clearance. The trimer [64Cu]Cu-9 showed a ~ 2.5-fold higher tumor uptake compared with the monomer [64Cu]Cu-8. Conclusions Functionalization of NOTI at the non-coordinating NH atoms of the imidazole residues for bioconjugation was straightforward and allowed the preparation of a homotrimeric RGD conjugate. After optimization of the synthesis, required building blocks to make NOTI-TVA 6 are now available on multi-gram scale. Modifications at the imidazole groups had no measurable impact on metal binding properties in vitro and in vivo suggesting that the NOTI scaffold is a promising candidate for the development of 64Cu-labeled multimeric/multifunctional radiotracers.

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Highly stable noble metal nanoparticles dispersible in biocompatible solvents: synthesis of cationic phosphonium gold nanoparticles in water and DMSO

Faraday Discussions ◽

10.1039/c5fd00131e ◽

2016 ◽

Vol 186 ◽

pp. 77-93 ◽

Cited By ~ 4

Author(s):

Yon Ju-Nam ◽

Wanisa Abdussalam-Mohammed ◽

Jesus J. Ojeda

Keyword(s):

Gold Nanoparticles ◽

Drug Carrier ◽

Aqueous Media ◽

Noble Metal Nanoparticles ◽

Great Opportunity ◽

Thiolate Ligands ◽

New Family ◽

Uv Visible ◽

Potential Use

In this work, we report the synthesis of novel cationic phosphonium gold nanoparticles dispersible in water and dimethyl sulfoxide (DMSO) for their potential use in biomedical applications. All the cationic-functionalising ligands currently reported in the literature are ammonium-based species. Here, the synthesis and characterisation of an alternative system, based on phosphonioalkylthiosulfate zwitterions and phosphonioalkylthioacetate were carried out. We have also demonstrated that our phosphonioalkylthiosulfate zwitterions readily disproportionate into phosphonioalkylthiolates in situ during the synthesis of gold nanoparticles produced by the borohydride reduction of gold(iii) salts. The synthesis of the cationic gold nanoparticles using these phosphonium ligands was carried out in water and DMSO. UV-visible spectroscopic and TEM studies have shown that the phosphonioalkylthiolates bind to the surface of gold nanoparticles which are typically around 10 nm in diameter. The resulting cationic-functionalised gold nanoparticles are dispersible in aqueous media and in DMSO, which is the only organic solvent approved by the U.S. Food and Drug Administration (FDA) for drug carrier tests. This indicates their potential future use in biological applications. This work shows the synthesis of a new family of phosphonium-based ligands, which behave as cationic masked thiolate ligands in the functionalisation of gold nanoparticles. These highly stable colloidal cationic phosphonium gold nanoparticles dispersed in water and DMSO can offer a great opportunity for the design of novel biorecognition and drug delivery systems.

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