scholarly journals Fluorescent metallacycle-cored polymers via covalent linkage and their use as contrast agents for cell imaging

2016 ◽  
Vol 113 (40) ◽  
pp. 11100-11105 ◽  
Author(s):  
Mingming Zhang ◽  
Shuya Li ◽  
Xuzhou Yan ◽  
Zhixuan Zhou ◽  
Manik Lal Saha ◽  
...  
Keyword(s):  
Cell Imaging ◽  
Noncovalent Interactions ◽  
Polymeric Materials ◽  
Quantum Yields ◽  
Covalent Bonds ◽  
Covalent Linkage ◽  
Amidation Reaction ◽  
Potential Applications ◽  
Significant Enrichment ◽  
Selection Of

The covalent linkage of supramolecular monomers provides a powerful strategy for constructing dynamic polymeric materials whose properties can be readily tuned either by the selection of monomers or the choice of functional linkers. In this strategy, the stabilities of the supramolecular monomers and the reactions used to link the monomers are crucial because such monomers are normally dynamic and can disassemble during the linking process, leading to mixture of products. Therefore, although noncovalent interactions have been widely introduced into metallacycle structures to prepare metallosupramolecular polymers, metallacycle-cored polymers linked by covalent bonds have been rarely reported. Herein, we used the mild, highly efficient amidation reaction between alkylamine and N-hydroxysuccinimide-activated carboxylic acid to link the pendent amino functional groups of a rhomboidal metallacycle 10 to give metallacycle-cored polymers P1 and P2, which further yielded nanoparticles at low concentration and transformed into network structures as the concentration increased. Moreover, these polymers exhibited enhanced emission and showed better quantum yields than metallacycle 10 in methanol and methanol/water (1/9, vol/vol) due to the aggregation-induced emission properties of a tetraphenylethene-based pyridyl donor, which serves as a precursor for metallacycle 10. The fluorescence properties of these polymers were further used in cell imaging, and they showed a significant enrichment in lung cells after i.v. injection. Considering the anticancer activity of rhomboidal Pt(II) metallacycles, this type of fluorescent metallacycle-cored polymers can have potential applications toward lung cancer treatment.

Simultaneously improving the ductility and strength of aromatic thermoset films

2021 ◽  
pp. 095400832110171
Author(s):  
Cheng Wang ◽  
Long Fei Zhang ◽  
Wa Li ◽  
Li Rong Yang ◽  
Jia Jun Ma ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Large Scale ◽  
Noncovalent Interactions ◽  
Ion Pair ◽  
Special Group ◽  
Covalent Bonds ◽  
New Class ◽  
Wide Range ◽  
Potential Applications ◽  
Mechanical Strengths

Aromatic thermoset materials have shown great potential applications in various fields owing to their excellent mechanical strengths. However, their poor ductility is still hinders their large-scale applications. In this study, a new class of aromatic thermosets consisting of two types of crosslinks was successfully developed by incorporating the special group imidazole into a type of crosslinked thermoset. One crosslink is constituted of reversible multiple noncovalent interactions containing “face-face” π–π stacking, “point-point” hydrogen bonds, and ion-pair electrostatic interactions, whereas the other is composed of permanent covalent bonds. Most importantly, the synergetic interplay among these reversible multiple noncovalent interactions enables them to evade the restrictions from the aromatic polymer skeletons to proceed with their dynamic dissociating-rebuilding processes, which can timely and effectively dissipate the internal stress. Finally, owing to the coefficient of these two types of crosslinks, a significantly enhanced ductility was successfully obtained on these aromatic thermosets and their tensile strengths were also improved. Such thermosets having simultaneously enhanced strengths and ductility are predicted to be eventually used in a wide range of applications.

scholarly journals Covalent Organic Frameworks: New Materials Platform for Photocatalytic Degradation of Aqueous Pollutants

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5600
Author(s):  
Yuhang Qian ◽  
Dongge Ma
Keyword(s):  
Near Infrared ◽  
Gas Adsorption ◽  
Degradation Mechanism ◽  
Co2 Reduction ◽  
Polymeric Materials ◽  
Structural Type ◽  
Research Area ◽  
Covalent Organic Frameworks ◽  
Covalent Bonds ◽  
Potential Applications

Covalent organic frameworks (COFs) are highly porous and crystalline polymeric materials, constructed by covalent bonds and extending in two or threedimensions. After the discovery of the first COF materials in 2005 by Yaghi et al., COFs have experienced exciting progress and exhibitedtheirpromising potential applications invarious fields, such as gas adsorption and separation, energy storage, optoelectronics, sensing and catalysis. Because of their tunablestructures, abundant, regular and customizable pores in addition to large specific surface area, COFs can harvest ultraviolet, visible and near-infrared photons, adsorb a large amount of substrates in internal structures and initiate surface redox reactions to act as effective organic photocatalysts for water splitting, CO2 reduction, organic transformations and pollutant degradation. In this review, we will discuss COF photocatalysts for the degradation of aqueous pollutants. The state-of-the-art paragon examples in this research area will be discussed according to the different structural type of COF photocatalysts. The degradation mechanism will be emphasized. Furthermore, the future development direction, challenges required to be overcome and the perspective in this field will be summarized in the conclusion.

Electronic criterion for categorizing the chalcogen and halogen bonds: sulfur–iodine interactions in crystals

2019 ◽  
Vol 75 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Ekaterina Bartashevich ◽  
Svetlana Mukhitdinova ◽  
Irina Yushina ◽  
Vladimir Tsirelson
Keyword(s):  
Electrostatic Potential ◽  
Noncovalent Interactions ◽  
Molecular Crystals ◽  
Mutual Orientation ◽  
Halogen Bonds ◽  
Covalent Bonds ◽  
Interatomic Distances ◽  
Different Types ◽  
Electrophilic Site ◽  
Selection Of

Diversity of mutual orientations of Y–S and I–X and covalent bonds in molecular crystals complicate categorizing noncovalent chalcogen and halogen bonds. Here, the different types of S...I interactions with short interatomic distances are analysed. The selection of S...I interactions for the categorization of the chalcogen and halogen bonds has been made using angles that determine the mutual orientation of electron lone pairs and σ-holes interacted S and I atoms. In complicated cases of noncovalent interactions with `hole-to-hole' of S and I orientations, distinguishing the chalcogen and halogen bonds is only possible if the atom is uniquely determined, which also provides the electrophilic site. The electronic criterion for chalcogen/halogen bonds categorizing that is based on analysis of dispositions of electron density and electrostatic potential minima along the interatomic lines has been suggested and its effectiveness has been demonstrated.

scholarly journals Carbon Nanotubes as Emerging Nanocarriers in Drug Delivery: An Overview

2020 ◽  
Vol 11 (03) ◽  
pp. 373-378
Author(s):  
Ashish Suttee ◽  
Vijay Mishra ◽  
Manvendra Singh ◽  
Pallavi Nayak ◽  
Pavani Sriram
Keyword(s):  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Noncovalent Interactions ◽  
Pharmacokinetic Parameters ◽  
Covalent Bonds ◽  
Chemically Modified ◽  
Drug Delivery Carrier ◽  
Allotropic Form ◽  
Cylindrical Tubes ◽  
Potential Applications

Carbon nanotubes (CNTs) have been frequently acquired as one of the fascinating and advanced nanocarriers for drug delivery and many potential applications due to its unique physicochemical properties. During recent years CNTs have been attracted by many researchers as a drug delivery carrier. CNTs are the third allotropic form of carbon-fullerenes rolled into cylindrical tubes. To be integrated into the biological systems, CNTs can be chemically modified or functionalized with therapeutically active molecules by forming stable covalent bonds or supramolecular assemblies based on noncovalent interactions. Owing to their high carrying capacity, biocompatibility, and specificity to cells, various cancer cells have been explored with CNTs for evaluation of pharmacokinetic parameters, cell viability, cytotoxicity, and drug delivery in tumor cells.

Novel organic, polymeric materials for electronics applications

2002 ◽  
Vol 722 ◽  
Author(s):  
Ram W. Sabnis ◽  
Mary J. Spencer ◽  
Douglas J. Guerrero
Keyword(s):  
Optical Density ◽  
Chemical Vapor ◽  
Polymeric Materials ◽  
Substantial Improvement ◽  
Polymeric Systems ◽  
Patterned Wafers ◽  
Visible Spectra ◽  
Potential Applications ◽  
Deep Ultraviolet ◽  
Deposited Films

AbstractNovel organic, polymeric materials and processes of depositing thin films on electronics substrates by chemical vapor deposition (CVD) have been developed and the lithographic behavior of photoresist coated over these CVD films at deep ultraviolet (DUV) wavelength has been evaluated. The specific monomers synthesized for DUV applications include [2.2](1,4)- naphthalenophane, [2.2](9,10)-anthracenophane and their derivatives which showed remarkable film uniformity on flat wafers and conformality over structured topography wafers, upon polymerization by CVD. The chemical, physical and optical properties of the deposited films have been characterized by measuring parameters such as thickness uniformity, solubility, conformality, adhesion to semiconductor substrates, ultraviolet-visible spectra, optical density, optical constants, defectivity, and resist compatibility. Scanning electron microscope (SEM) photos of cross-sectioned patterned wafers showed verticle profiles with no footing, standing waves or undercut. Resist profiles down to 0.10 νm dense lines and 0.09 νm isolated lines were achieved in initial tests. CVD coatings generated 96-100% conformal films, which is a substantial improvement over commercial spin-on polymeric systems. The light absorbing layers have high optical density at 248 nm and are therefore capable materials for DUV lithography applications. CVD is a potentially useful technology to extend lithography for sub-0.15 νm devices. These films have potential applications in microelectronics, optoelectronics and photonics.

scholarly journals Study of Physical and Degradation Properties of 3D-Printed Biodegradable, Photocurable Copolymers, PGSA-co-PEGDA and PGSA-co-PCLDA

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1263 ◽  
Author(s):  
June-Yo Chen ◽  
Joanne Hwang ◽  
Wai-Sam Ao-Ieong ◽  
Yung-Che Lin ◽  
Yi-Kong Hsieh ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Weight Ratio ◽  
Polymeric Materials ◽  
Pure Substance ◽  
Digital Light Processing ◽  
Glycol Diacrylate ◽  
Young’S Moduli ◽  
Potential Applications ◽  
Degradation Properties

As acrylated polymers become more widely used in additive manufacturing, their potential applications toward biomedicine also raise the demand for biodegradable, photocurable polymeric materials. Polycaprolactone diacrylate (PCLDA) and poly(ethylene glycol) diacrylate (PEGDA) are two popular choices of materials for stereolithography (SLA) and digital light processing additive manufacturing (DLP-AM), and have been applied to many biomedical related research. However, both materials are known to degrade at a relatively low rate in vivo, limiting their applications in biomedical engineering. In this work, biodegradable, photocurable copolymers are introduced by copolymerizing PCLDA and/or PEGDA with poly(glycerol sebacate) acrylate (PGSA) to form a network polymer. Two main factors are discussed: the effect of degree of acrylation in PGSA and the weight ratio between the prepolymers toward the mechanical and degradation properties. It is found that by blending prepolymers with various degree of acrylation and at various weight ratios, the viscosity of the prepolymers remains stable, and are even more 3D printable than pure substances. The formation of various copolymers yielded a database with selectable Young’s moduli between 0.67–10.54 MPa, and the overall degradation rate was significantly higher than pure substance. In addition, it is shown that copolymers fabricated by DLP-AM fabrication presents higher mechanical strength than those fabricated via direct UV exposure. With the tunable mechanical and degradation properties, the photocurable, biodegradable copolymers are expected to enable a wider application of additive manufacturing toward tissue engineering.

Novel Behavior in Smart Polymeric Materials: Stress Memory and its Potential Applications

2016 ◽  
Vol 97 ◽  
pp. 93-99
Author(s):  
Jin Lian Hu ◽  
Harishkumar Narayana
Keyword(s):  
Magnetic Field ◽  
Shape Memory ◽  
Smart Materials ◽  
Shape Memory Polymers ◽  
Polymeric Materials ◽  
External Stimulus ◽  
Artificial Muscles ◽  
Recovery Stress ◽  
Stress Memory ◽  
Potential Applications

Materials, structures and systems, responsive to an external stimulus are smart and adaptive to our human demands. Among smart materials, polymers with shape memory effect are at the forefront of research leading to comprehensive publications and wide applications. In this paper, we extend the concept of shape memory polymers to stress memory ones, which have been discovered recently. Like shape memory, stress memory represents a phenomenon where the stress in a polymer can be programmed, stored and retrieved reversibly with an external stimulus such as temperature and magnetic field. Stress memory may be mistaken as the recovery stress which was studied quite broadly. Our further investigation also reveals that stress memory is quite different from recovery stress containing multi-components including elastic and viscoelastic forces in addition to possible memory stress. Stress memory could be used into applications such as sensors, pressure garments, massage devices, electronic skins and artificial muscles. The current revelation of stress memory potentials is emanated from an authentic application of memory fibres, films, and foams in the smart compression devices for the management of chronic and therapeutic disorders.

scholarly journals Methods and applications for visualization of SNOMED CT concept sets

2014 ◽  
Vol 05 (01) ◽  
pp. 127-152 ◽  
Author(s):  
E. Sundvall ◽  
K.R. Gøeg ◽  
A.R. Højen
Keyword(s):  
Content Management ◽  
Graph Layout ◽  
Snomed Ct ◽  
Focus Group Interviews ◽  
Web Based ◽  
Hierarchical Relations ◽  
Potential Applications ◽  
Group Interviews ◽  
And Training ◽  
Selection Of

SummaryInconsistent use of SNOMED CT concepts may reduce comparability of information in health information systems. Terminology implementation should be approached by common strategies for navigating and selecting proper concepts. This study aims to explore ways of illustrating common pathways and ancestors of particular sets of concepts, to support consistent use of SNOMED CT and also assess potential applications for such visualizations.The open source prototype presented is an interactive web-based re-implementation of the terminology visualization tool TermViz that provides an overview of concepts and their hierarchical relations. It provides terminological features such as interactively rearranging graphs, fetching more concept nodes, highlighting least common parents and shared pathways in merged graphs etc.Four teams of three to four people used the prototype to complete a terminology mapping task and then, in focus group interviews, discussed the user experience and potential future tool usage. Potential purposes discussed included SNOMED CT search and training, consistent selection of concepts and content management.The evaluation indicated that the tool may be useful in many contexts especially if integrated with existing systems, and that the graph layout needs further tuning and development.Citation: Højen AR, Sundvall E, Gøeg KR. Methods and applications for visualization of SNOMED CT concept sets. Appl Clin Inf 2014; 5: 127–152http://dx.doi.org/10.4338/ACI-2013-09-RA-0071

Dynamic Covalent Bonds in Polymeric Materials

2019 ◽  
Vol 58 (29) ◽  
pp. 9682-9695 ◽  
Author(s):  
Progyateg Chakma ◽  
Dominik Konkolewicz
Keyword(s):  
Polymeric Materials ◽  
Covalent Bonds

scholarly journals Moleculary imprinted micro- and nanoparticles for cancer associated glycan motifs

2021 ◽  
Author(s):  
◽  
Liliia Mavliutova
Keyword(s):  
Molecularly Imprinted Polymers ◽  
Binding Sites ◽  
Cell Imaging ◽  
Functional Monomers ◽  
Crosslinked Polymer ◽  
Relative Contribution ◽  
Potential Applications ◽  
Specific Receptors ◽  
Cancer Glycosylation ◽  
Complementary Binding

Sialic acids are an important family of monosaccharides that are typically found as terminal moieties of glycans. Aberrant sialylation has been proven to correlate with various diseases including cancer. Glycosylation analysis is complex due to high diversityof the glycan isomers and their low abundance. Antibodies and lectins are commonly used in glycan purification and enrichment. However, high cost, poor availability, and limitation in storage/testing conditions hinders their application on a broader scale. This thesis is focused on the development of alternative glycan specific receptors with their potential applications in glycomics and cell imaging. The underlying technique for producing the synthetic receptors is molecular imprinting. Highly complementary binding sites are formed by fixing pre-ordered template/functional monomer complexes into a highly crosslinked polymer matrix. Fundamental investigation of this intermolecular imprinting approach in the imprinting of glycosylated targets is reported here. The core of this study focuses on the elucidation of relative contribution of orthogonally interacting functional monomers, their structural tuning and the importance of monomer, solvent and counterion choice on the imprinting. Molecularly imprinted polymers (MIPs) are developed as particles of different sizes for glycan/glycopeptide enrichment applications or combined with fluorescent reportergroups for use as glycan imaging nanolabels. Special attention is given to the improvement of sialic acid MIP selectivities toward particular structures associated with cancer biomarkers. Development of MIPs against such complex targets includes design of linkage selective MIPs with comprehensive studies of the affinities and selectivities of the final glycan specific materials.

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