jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tianyue Jiang | Chendan Liu | Xiao Xu | Bingfang He | Ran Mo
Source: Frontiers in Bioengineering and Biotechnology (review, 2021-02-26)
Field: Materials Science — Biomaterials

Formation Mechanism and Biomedical Applications of Protease-Manipulated Peptide Assemblies Exploiting enzyme-catalyzed reactions to manipulate molecular assembly has been considered as an attractive bottom-up nanofabrication approach to developing a variety of nano-, micro-, and macroscale structures. Upon enzymatic catalysis, peptides and their derivatives transform to assemblable building blocks that form ordered architecture by non-covalent interactions. The peptide assemblies with unique characteristics have great potential for applications in bionanotechnology and biomedicine. In this mini review, we describe typical mechanisms of the protease-instructed peptide assembly <i>via</i> bond-cleaving or bond-forming reactions, and outline biomedical applications of the peptide assemblies, such as drug depot, sustained release, controlled release, gelation-regulated cytotoxicity, and matrix construction. Nanobiotechnology ; Peptide ; Nanotechnology ; Covalent bond ; Protease ; Chemistry ; Combinatorial chemistry ; Cleave ; Materials science ; Enzyme ; Biochemistry ; Nanoparticle ; Organic chemistry Supramolecular Self-Assembly in Materials ; Chemical Synthesis and Analysis ; Antimicrobial Peptides and Activities
Authors: A. Lapresta-Fernández | Alfonso Salinas‐Castillo | L.F. Capitán‐Vallvey
Source: Scientific Reports (article, 2021-02-17)
Field: Materials Science — Polymers and Plastics

Synthesis of a thermoresponsive crosslinked MEO2MA polymer coating on microclusters of iron oxide nanoparticles Encapsulation of magnetic nanoparticles (MNPs) of iron (II, III) oxide (Fe<sub>3</sub>O<sub>4</sub>) with a thermopolymeric shell of a crosslinked poly(2-(2-methoxyethoxy)ethyl methacrylate) P(MEO<sub>2</sub>MA) is successfully developed. Magnetic aggregates of large size, around 150-200 nm are obtained during the functionalization of the iron oxide NPs with vinyl groups by using 3-butenoic acid in the presence of a water soluble azo-initiator and a surfactant, at 70 °C. These polymerizable groups provide a covalent attachment of the P(MEO<sub>2</sub>MA) shell on the surface of the MNPs while a crosslinked network is achieved by including tetraethylene glycol dimethacrylate in the precipitation polymerization synthesis. Temperature control is used to modulate the swelling-to-collapse transition volume until a maximum of around 21:1 ratio between the expanded: shrunk states (from 364 to 144 nm in diameter) between 9 and 49 °C. The hybrid Fe<sub>3</sub>O<sub>4</sub>@P(MEO<sub>2</sub>MA) microgel exhibits a lower critical solution temperature of 21.9 °C below the corresponding value for P(MEO<sub>2</sub>MA) (bulk, 26 °C). The MEO<sub>2</sub>MA coating performance in the hybrid microgel is characterized by dynamic light scattering and transmission electron microscopy. The content of preformed MNPs [up to 30.2 (wt%) vs. microgel] was established by thermogravimetric analysis while magnetic properties by vibrating sample magnetometry. Coating ; Nanoparticle ; Polymer ; Iron oxide nanoparticles ; Materials science ; Chemical engineering ; Nanotechnology ; Composite material Polymer Nanocomposites and Properties ; Advanced Theoretical and Applied Studies in Material Sciences and Geometry ; Material Properties and Applications
Authors: Ilya G. Shenderovich
Source: Symmetry (article, 2021-04-27)
Field: Chemistry — Physical and Theoretical Chemistry

Actual Symmetry of Symmetric Molecular Adducts in the Gas Phase, Solution and in the Solid State This review discusses molecular adducts, whose composition allows a symmetric structure. Such adducts are popular model systems, as they are useful for analyzing the effect of structure on the property selected for study since they allow one to reduce the number of parameters. The main objectives of this discussion are to evaluate the influence of the surroundings on the symmetry of these adducts, steric hindrances within the adducts, competition between different noncovalent interactions responsible for stabilizing the adducts, and experimental methods that can be used to study the symmetry at different time scales. This review considers the following central binding units: hydrogen (proton), halogen (anion), metal (cation), water (hydrogen peroxide). Adduct ; Steric effects ; Halogen ; Symmetry (geometry) ; Hydrogen bond ; Chemistry ; Computational chemistry ; Chemical physics ; Phase (matter) ; Non-covalent interactions ; Molecule ; Stereochemistry ; Organic chemistry ; Mathematics Crystallography and molecular interactions ; Chemical Thermodynamics and Molecular Structure ; Molecular Spectroscopy and Structure
Authors: Pei Yang | Gustavo Tontini | Jiacheng Wang | Ian A. Kinloch | Suelen Barg
Source: Nanotechnology (article, 2021-01-25)
Field: Materials Science — Materials Chemistry

Ice-templated hybrid graphene oxide—graphene nanoplatelet lamellar architectures: tuning mechanical and electrical properties The traditional freeze-casting route for processing graphene-based aerogels is generally restricted to aqueously dispersed flakes of graphene oxide (GO) and post-processing reduction treatments, which brings restrictions to the aerogels electrical properties. In this work, we report a versatile aqueous processing route that uses the ability of GO todisperse graphene nanoplatelets (GNP) to produce rGO-GNP lamellar aerogels via unidirectional freeze-casting. In order to optimise the properties of the aerogel, GO-GNP dispersions were partially reduced by L-ascorbic acid prior to freeze-casting to tune the carbon and oxygen (C/O) ratio. The aerogels were then heat treated after casting to fully reduce the GO. The chemical reduction time was found to control the microstructure of the resulting aeorgels and thus to tune their electrical and mechanical properties. An rGO-GNP lamellar aerogel with density of 20.8 ± 0.8 mg cm<sup>-3</sup> reducing using a reduction of 60 min achieved an electrical conductivity of 42.3 S m<sup>-1</sup>. On the other hand, an optimal reduction time of 35 min led to an aerogel with compressive modulus of 0.51 ±0.06 MPa at a density of 23.2 ± 0.7 mg cm<sup>-3</sup>, revealing a compromise between the tuning of electrical and mechanical properties. We show the present processing route can also be easily applied to produce lamellar aerogels on other graphene-based materials such as electrochemically exfoliated graphene. Graphene ; Materials science ; Aerogel ; Lamellar structure ; Oxide ; Composite material ; Microstructure ; Electrical resistivity and conductivity ; Casting ; Graphene oxide paper ; Nanotechnology ; Chemical engineering ; Metallurgy Layered Double Hydroxides Synthesis and Applications ; Supercapacitor Materials and Fabrication ; Advanced Photocatalysis Techniques
Authors: Margot Jacquet | Miriam Izzo | Silvio Osella | Sylwia Kozdra | Paweł Piotr Michałowski | Dariusz Gołowicz | Krzysztof Kazimierczuk | Maciej T. Gorzkowski | Adam Lewera | M. Teodorczyk | Bartosz Trzaskowski | Rafał Jurczakowski | Daniel T. Gryko | Joanna Kargul
Source: Nanoscale (article, 2021-01-01)
Field: Chemistry — Electrochemistry

Development of a universal conductive platform for anchoring photo- and electroactive proteins using organometallic terpyridine molecular wires The construction of an efficient conductive interface between electrodes and electroactive proteins is a major challenge in the biosensor and bioelectrochemistry fields to achieve the desired nanodevice performance. Concomitantly, metallo-organic terpyridine wires have been extensively studied for their great ability to mediate electron transfer over a long-range distance. In this study, we report a novel stepwise bottom-up approach for assembling bioelectrodes based on a genetically modified model electroactive protein, cytochrome c553 (cyt c553) and an organometallic terpyridine (TPY) molecular wire self-assembled monolayer (SAM). Efficient anchoring of the TPY derivative (TPY-PO(OH)2) onto the ITO surface was achieved by optimising solvent composition. Uniform surface coverage with the electroactive protein was achieved by binding the cyt c553 molecules via the C-terminal His6-tag to the modified TPY macromolecules containing Earth abundant metallic redox centres. Photoelectrochemical characterisation demonstrates the crucial importance of the metal redox centre for the determination of the desired electron transfer properties between cyt and the ITO electrode. Even without the cyt protein, the ITO-TPY nanosystem reported here generates photocurrents whose densities are 2-fold higher that those reported earlier for ITO electrodes functionalised with the photoactive proteins such as photosystem I in the presence of an external mediator, and 30-fold higher than that of the pristine ITO. The universal chemical platform for anchoring and nanostructuring of (photo)electroactive proteins reported in this study provides a major advancement for the construction of efficient (bio)molecular systems requiring a high degree of precise supramolecular organisation as well as efficient charge transfer between (photo)redox-active molecular components and various types of electrode materials. Terpyridine ; Anchoring ; Rational design ; Materials science ; Electron transfer ; Template ; Nanotechnology ; Chemistry ; Organic chemistry ; Metal ; Engineering ; Metallurgy Electrochemical Analysis and Applications ; Molecular Junctions and Nanostructures ; Electrochemical sensors and biosensors
Authors: Taryn M. Golding | Mziyanda Mbaba | Gregory S. Smith
Source: Dalton Transactions (article, 2021-01-01)
Field: Chemistry — Spectroscopy

Modular synthesis of antimalarial quinoline-based PGM metallarectangles A new ditopic, quinoline-based ligand L (7-chloro-4-(pyridin-4-yl)quinoline) was synthesized <i>via</i> a Suzuki cross-coupling reaction. The ligand was utilized to synthesize the corresponding half-sandwich iridium(III) and ruthenium(II) binuclear complexes (1c and 1d) and the subsequent metallarectangles (2c, 2d, 3c, and 3d), <i>via</i> [2 + 2] coordination-driven self-assembly. Single-crystal X-ray diffraction confirmed the proposed molecular structure of the binuclear complex [{IrCl<sub>2</sub>(Cp*)}<sub>2</sub>(μ-L)] (1c) and DFT calculations were used to predict the optimized geometry of the rectangular nature of [{Ir(μ-Cl)(Cp*)}<sub>4</sub>(μ-L)<sub>2</sub>](CF<sub>3</sub>SO<sub>3</sub>)<sub>4</sub> (2c). All of the metallarectangles were isolated as their triflate salts and characterized using various spectroscopic (<sup>1</sup>H, <sup>13</sup>C{<sup>1</sup>H}, DOSY NMR, and IR spectroscopy) and analytical techniques (ESI-MS). The synthesized compounds were screened against the NF54 chloroquine-sensitive (CQS) and K1 chloroquine-resistant (CQR) strains of <i>Plasmodium falciparum</i>. Incorporation of the ubiquitous quinoline core and metal complexation significantly enhanced the <i>in vitro</i> biological activity, with an increase in the nuclearity correlating with an increase in the resultant antiplasmodial activity. This was observed across both parasitic strains, alluding to the potential of supramolecular metallarectangles to act as antiplasmodial agents. Inhibition of haemozoin formation was considered a potential mechanism of action and selected metallarectangles exhibit β-haematin inhibition activity with near comparable activity to chloroquine. Quinoline ; Chemistry ; Ligand (biochemistry) ; Trifluoromethanesulfonate ; Supramolecular chemistry ; Stereochemistry ; Combinatorial chemistry ; Proton NMR ; Ruthenium ; Crystallography ; Crystal structure ; Organic chemistry ; Catalysis ; Receptor Molecular Sensors and Ion Detection ; Metal complexes synthesis and properties ; Supramolecular Chemistry and Complexes
Authors: Ana M. Gómez | Clara Uriel | Ainhoa Oliden‐Sánchez | Jorge Bañuelos | Inmaculada García‐Moreno | J. Cristobal López
Source: The Journal of Organic Chemistry (article, 2021-06-22)
Field: Materials Science — Materials Chemistry

A Concise Route to Water-Soluble 2,6-Disubstituted BODIPY-Carbohydrate Fluorophores by Direct Ferrier-Type C-Glycosylation Novel, linker-free, BODIPY-carbohydrate derivatives containing sugar residues at positions C2 and C6 are efficiently obtained by, hitherto unreported, Ferrier-type <i>C</i>-glycosylation of 8-aryl-1,3,5,7-tetramethyl BODIPYs with commercially available tri-<i>O</i>-acetyl-d-glucal followed by saponification. This transformation, which involves the electrophilic aromatic substitution (S<sub>E</sub>Ar) of the dipyrrin framework with an allylic oxocarbenium ion, provides easy access to BODIPY-carbohydrate hybrids with excellent photophysical properties and a weaker tendency to aggregate in concentrated water solutions. Chemistry ; BODIPY ; Glycosylation ; Oxocarbenium ; Carbohydrate ; Allylic rearrangement ; Linker ; Combinatorial chemistry ; Organic chemistry ; Fluorescence ; Biochemistry ; Catalysis ; Nucleophile Luminescence and Fluorescent Materials ; Porphyrin and Phthalocyanine Chemistry ; Molecular Sensors and Ion Detection
Authors: Gonzalo Campillo‐Alvarado | Michael Bernhardt | Daniel W. Davies | Julio A. N. T. Soares | Toby J. Woods | Ying Diao
Source: The Journal of Chemical Physics (article, 2021-08-17)
Field: Materials Science — Materials Chemistry

Modulation of π-stacking modes and photophysical properties of an organic semiconductor through isosteric cocrystallization We report on the control of π-stacking modes (herringbone vs slipped-stack) and photophysical properties of 9,10-bis((E)-2-(pyridin-4-yl)vinyl)anthracene (BP4VA), an anthracene-based organic semiconductor (OSC), by isosteric cocrystallization (i.e., the replacement of one functional group in a coformer with another of "similar" electronic structure) with 2,4,6-trihalophenols (3X-ph-OH, where X = Cl, Br, and I). Specifically, BP4VA organizes as slipped-stacks when cocrystallized with 3Cl-ph-OH and 3Br-ph-OH, while cocrystallization with 3I-ph-OH results in a herringbone mode. The photoluminescence and molecular frontier orbital energy levels of BP4VA were effectively modulated by the presence of 3X-ph-OH through cocrystallization. We envisage that the cocrystallization of OSCs with minimal changes in cocrystal formers can provide access to convenient structural and property diversification for advanced single-crystal electronics. Stacking ; Anthracene ; Cocrystal ; Crystal structure ; Organic semiconductor ; Chemistry ; Crystallography ; Crystal engineering ; Semiconductor ; Photoluminescence ; Dendrimer ; Stereochemistry ; Materials science ; Supramolecular chemistry ; Molecule ; Photochemistry ; Optoelectronics ; Hydrogen bond ; Organic chemistry Luminescence and Fluorescent Materials ; Crystallography and molecular interactions ; Molecular Sensors and Ion Detection
Authors: Antoine Combes | Khanh-Nam Tang | Andrey S. Klymchenko | Andreas Reisch
Source: Journal of Colloid and Interface Science (article, 2021-09-19)
Field: Materials Science — Surfaces, Coatings and Films

Protein-like particles through nanoprecipitation of mixtures of polymers of opposite charge Polymer ; Methacrylate ; Surface charge ; Isoelectric point ; Methacrylic acid ; Nanoparticle ; Polyelectrolyte ; Chemistry ; Fluorescence ; Copolymer ; Polymer chemistry ; Chemical engineering ; Hydrodynamic radius ; Coacervate ; Materials science ; Nanotechnology ; Organic chemistry ; Chromatography ; Physical chemistry Polymer Surface Interaction Studies ; Nanoparticle-Based Drug Delivery ; Microfluidic and Capillary Electrophoresis Applications
Authors: Max Attwood | Hiroki Akutsu | Lee Martin | Toby J. Blundell | Pierre Le Maguerè | Scott S. Turner
Source: Dalton Transactions (article, 2021-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Exceptionally high temperature spin crossover in amide-functionalised 2,6-bis(pyrazol-1-yl)pyridine iron(<scp>ii</scp>) complex revealed by variable temperature Raman spectroscopy and single crystal X-ray diffraction The synthesis of a novel amide-functionalised 2,6-bis(pyrazol-1-yl)pyridine-4-carboxamide ligand (bppCONH<sub>2</sub>) is described. The complex salts [Fe(bppCONH<sub>2</sub>)<sub>2</sub>](BF<sub>4</sub>)<sub>2</sub> and [Fe(bppCONH<sub>2</sub>)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub> were synthesised and characterised by SQUID magnetometry, differential scanning calorimetry, variable temperature Raman spectroscopy and single crystal X-ray diffraction. DSC measurements of [Fe(bppCONH<sub>2</sub>)<sub>2</sub>](BF<sub>4</sub>)<sub>2</sub> indicate a spin-crossover (SCO) transition with T↑ at 481 K and T↓ at 461 K, showing a 20 K hysteresis. DSC for the perchlorate salt shows an SCO transition with T↑ at 459 K and T↓ at 445 K with a 14 K hysteresis. For the BF<sub>4</sub><sup>-</sup> salt analysis of low and high-spin state crystal structures at 101, 290 and 500 K, suggest stabilisation of the low spin state due to the formation of 1D hydrogen-bonded cationic chains. Variable temperature Raman studies of the BF<sub>4</sub> salt support the presence of a high temperature SCO. It is speculated that the presence of hysteresis may be attributed to differences in the inter-molecular hydrogen bonding in the low spin and high spin states. Spin crossover ; Pyridine ; Amide ; Crystallography ; Raman spectroscopy ; Ligand (biochemistry) ; Chemistry ; Diffraction ; Single crystal ; Spin transition ; Medicinal chemistry ; Organic chemistry ; Physics ; Receptor ; Optics Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Metal complexes synthesis and properties
Authors: Enikő Bitay | Attila Gergely | Ioan Balint | Kristóf Molnár | István Fülöp | E. Fogarasi | Zoltán‐István Szabó
Source: eXPRESS Polymer Letters (article, 2021-01-01)
Field: Materials Science — Biomaterials

Preparation and characterization of lapatinib-loaded PVP nanofiber amorphous solid dispersion by electrospinning Lapatinib-loaded polyvinylpyrrolidone-based nanofibrous solid dispersions were prepared by electrospinning in order to enhance the aqueous solubility and dissolution rate of the anticancer drug. The prepared nanofibers were characterized by smooth-surfaced, homogenous filaments with average diameters of 462160 nm determined by scanning electron microscopy. The crystalline to amorphous transition of the active ingredient was confirmed by differential scanning calorimetry, while Raman spectroscopy showed that amorphous lapatinib was uniformly distributed in the fibrous structures. Gas chromatographic analyses revealed that residual solvents in the nanofiber mats were below the ICH Guideline Q3C recommended limits, namely ethanol 10.92.3 ppm (recommended limit 5000 ppm) and dimethyl formamide 78056 ppm (recommended limit 880 ppm). Determination of drug content and in vitro dissolution studies were performed in order to observe the influence of electrospinning on the drug release characteristics of the product obtained. The lapatinib content in the nanofibers were measured to be 16.760.11 w/w%, whereas the dissolution study at pH 6.8 indicated a rapid disintegration of the nanofibrous mats, releasing ~70% of the drug loading under 5 minutes compared to the ~0.05% dissolution of the neat lapatinib ditosylate. The results confirm the applicability of electrospinning for the improvement of physicochemical characteristics of the poorly bioavailable anticancer agent. Materials science ; Nanofiber ; Electrospinning ; Amorphous solid ; Characterization (materials science) ; Dispersion (optics) ; Lapatinib ; Composite material ; Chemical engineering ; Nanotechnology ; Polymer science ; Polymer ; Organic chemistry ; Optics ; Cancer Electrospun Nanofibers in Biomedical Applications
Authors: Junta Yonemoto | Yasuyuki Maki | Isabel Koh | Kazuya Furusawa | Masahiko Annaka
Source: Biomacromolecules (article, 2021-08-03)
Field: Materials Science — Biomaterials

Formation of Multi-Channel Collagen Gels Investigated Using Particle Tracking Microrheology Collagen is one of the most common materials used to form scaffolds for tissue engineering applications. The multi-channel collagen gel (MCCG) obtained by the dialysis of an acidic collagen solution in a neutral buffer solution has a unique structure, with many capillaries of diameters several tens to a few hundred micrometers, and could be a potential candidate as a biomimetic scaffold for three-dimensional tissue engineering. In the present study, the formation of MCCG was investigated by <i>in situ</i> rheological measurements based on a particle tracking method (particle tracking microrheology, PTM). PTM enabled us to measure changes in the rheological properties of collagen solutions under the continuous exchange of substances during dialysis. When an observation plane was set perpendicular to the direction of gel growth, we first observed convectional flow of the collagen solution, followed by phase separation and gelation. We showed that the structure of the MCCG originated from the transient structure formed during the initial stage of viscoelastic phase separation and was fixed by the subsequent gelation. Microrheology ; Rheology ; Viscoelasticity ; Particle (ecology) ; Materials science ; Chemical engineering ; Phase (matter) ; Tissue engineering ; Tracking (education) ; Composite material ; Biomedical engineering ; Chemistry Collagen: Extraction and Characterization ; Blood properties and coagulation ; Proteins in Food Systems
Authors: María Mar Quesada‐Moreno | Pablo Pinacho | Cristóbal Pérez | Marina Šekutor | Peter R. Schreiner | Melanie Schnell
Source: Chemistry - A European Journal (article, 2021-01-29)
Field: Chemistry — Spectroscopy

Do Docking Sites Persist Upon Fluorination? The Diadamantyl Ether‐Aromatics Challenge for Rotational Spectroscopy and Theory Fluorinated derivatives of biological molecules have proven to be highly efficient at modifying the biological activity of a given protein through changes in the stability and the kind of docking interactions. These interactions can be hindered or facilitated based on the hydrophilic/hydrophobic character of a particular protein region. Diadamantyl ether (C<sub>20</sub> H<sub>30</sub> O) possesses both kinds of docking sites, serving as a good template to model these important contacts with aromatic fluorinated counterparts. In this work, an experimental study on the structures of several complexes between diadamantyl ether and benzene as well as a series of fluorinated benzenes is reported to analyze the effect of H→F substitution on the interaction and structure of the resulting molecular clusters using rotational spectroscopy. All experimentally observed complexes are largely dominated by London dispersion interactions with the hydrogen-terminated surface areas of diadamantyl ether. Already single substitution of one hydrogen atom with fluorine changes the preferred docking site of the complexes. However, the overall contributions of the different intermolecular interactions are similar for the different complexes, contrary to previous studies focusing on the difference in interactions using fluorinated and non-fluorinated molecules. Chemistry ; Docking (animal) ; Ether ; Molecule ; Hydrogen bond ; Intermolecular force ; Computational chemistry ; Benzene ; Fluorine ; London dispersion force ; Spectroscopy ; Stereochemistry ; van der Waals force ; Organic chemistry Molecular Spectroscopy and Structure ; Advanced Chemical Physics Studies ; Atmospheric Ozone and Climate