Only in Titles

Search results for: CHEMISTRY

paperclip

#34563032   2021/09/17 To Up

Stimuli-Responsive Nucleotide-Amino Acid Hybrid Supramolecular Hydrogels.

The ability to assemble chemically different gelator molecules into complex supramolecular hydrogels provides excellent opportunities to construct functional soft materials. Herein, we demonstrate the formation of hybrid nucleotide-amino acid supramolecular hydrogels. These are generated by the silver ion (Ag)-triggered formation of silver-guanosine monophosphate (GMP) dimers, which undergo self-assembly through non-covalent interactions to produce nanofilaments. This process results in a concomitant pH reduction due to the abstraction of a proton from the guanine residue, which triggers the in situ gelation of a pH-sensitive amino acid, N-fluorenylmethyloxycarbonyl tyrosine (FY), to form nucleotide-amino acid hybrid hydrogels. Alterations in the supramolecular structures due to changes in the assembly process are observed, with the molar ratio of Ag:GMP:FY affecting the assembly kinetics, and the resulting supramolecular organisation and mechanical properties of the hydrogels. Higher Ag:GMP stoichiometries result in almost instantaneous gelation with non-orthogonal assembly of the gelators, while at lower molar ratios, orthogonal assembly is observed. Significantly, by increasing the pH as an external stimulus, nanofilaments comprising FY can be selectively disassembled from the hybrid hydrogels. Our results demonstrate a simple approach for the construction of multicomponent stimuli-responsive supramolecular hydrogels with adaptable network and mechanical properties.
Matthew Mulvee, Natasa Vasiljevic, Stephen Mann, Avinash J Patil

1126 related Products with: Stimuli-Responsive Nucleotide-Amino Acid Hybrid Supramolecular Hydrogels.

100 mg2.5 g1 mg1 mg 1 G1 g1 mg5 mg5 mg500 mg 25 G100ml

Related Pathways

paperclip

#34563031   2021/09/17 To Up

Robust Silica-Bacterial Cellulose Composite Aerogel Fibers for Thermal Insulation Textile.

Aerogels are nanoporous materials with excellent properties, especially super thermal insulation. However, owing to their serious high brittleness, the macroscopic forms of aerogels are not sufficiently rich for the application in some fields, such as thermal insulation clothing fabric. Recently, freeze spinning and wet spinning have been attempted for the synthesis of aerogel fibers. In this study, robust fibrous silica-bacterial cellulose (BC) composite aerogels with high performance were synthesized in a novel way. Silica sol was diffused into a fiber-like matrix, which was obtained by cutting the BC hydrogel and followed by secondary shaping to form a composite wet gel fiber with a nanoscale interpenetrating network structure. The tensile strength of the resulting aerogel fibers reached up to 5.4 MPa because the quantity of BC nanofibers in the unit volume of the matrix was improved significantly by the secondary shaping process. In addition, the composite aerogel fibers had a high specific area (up to 606.9 m/g), low density (less than 0.164 g/cm), and outstanding hydrophobicity. Most notably, they exhibited excellent thermal insulation performance in high-temperature (210 °C) or low-temperature (-72 °C) environments. Moreover, the thermal stability of CAFs (decomposition temperature was about 330 °C) was higher than that of natural polymer fiber. A novel method was proposed herein to prepare aerogel fibers with excellent performance to meet the requirements of wearable applications.
Huazheng Sai, Meijuan Wang, Changqing Miao, Qiqi Song, Yutong Wang, Rui Fu, Yaxiong Wang, Litong Ma, Yan Hao

1789 related Products with: Robust Silica-Bacterial Cellulose Composite Aerogel Fibers for Thermal Insulation Textile.

0.2 mg10 mg 500 ml 1 mg0.1 mg12.5 mg50 assays100μg

Related Pathways

paperclip

#34563029   2021/09/16 To Up

Silica Xerogel Doped with Iron(III) as Sensor Material for Salicylhydroxamic Acid Determination in Urine.

Salicylhydroxamic acid (SHA) is used as antimicrobic medicine and its concentration has to be monitored in urine. For the first time, silica xerogels doped with iron(III) have been proposed as sensor materials for SHA determination in biological samples. Three xerogels with iron(III) content in the range of 0.04-1.74% wt have been synthesized. BET surface area of these xerogels has varied in the range of 696-529 m/g and total pore volume has varied in the range of 0.92-0.23 cm/g. Complex formation between immobilized iron(III) and salicylhydroxamic acid has been investigated with solid phase spectrophotometry and IR spectroscopy. Orange-brown iron(III)-SHA complex with 1:1 stoichiometry is formed at pH 1-4 with half-reaction time of 17 min. Silica xerogel doped with 0.33% wt iron(III)) has been used as sensor material for SHA solid phase spectrophotometric determination (LOD 1.4 mg/L ( = 3), analytical range 4-230 mg/L). Proposed sensor material has been applied for SHA determination in biological samples of synthetic and human urine. The proposed procedure is characterized by a good level of accuracy (recovery values 97-120%) and precision (RSD values 4-9%) and can be recommended for pharmacokinetic-pharmacodynamic studies of hydroxamic acid-based medications.
Maria A Morosanova, Vitaliy A Kovalev, Elena I Morosanova

1087 related Products with: Silica Xerogel Doped with Iron(III) as Sensor Material for Salicylhydroxamic Acid Determination in Urine.

100tests100Tests400Tests100tests100Tests100tests100 assays100 μl1 kit1kg0.1ml (1mg/ml)

Related Pathways

paperclip

#34563027   2021/09/14 To Up

Chemically Crosslinked Methylcellulose Substrates for Cell Sheet Engineering.

Methylcellulose (MC) hydrogels have been successfully proposed in the field of cell sheet engineering (CSE), allowing cell detachment from their surface by lowering the temperature below their transition temperature (T). Among the main limitations of pristine MC hydrogels, low physical stability and mechanical performances limit the breadth of their potential applications. In this study, a crosslinking strategy based on citric acid (CA) was used to prepare thermoresponsive MC hydrogels, with different degrees of crosslinking, to exploit their possible use as substrates in CSE. The investigated amounts of CA did not cause any cytotoxic effect while improving the mechanical performance of the hydrogels (+11-fold increase in E, compared to control MC). The possibility to obtain cell sheets (CSs) was then demonstrated using murine fibroblast cell line (L929 cells). Cells adhered on crosslinked MC hydrogels' surface in standard culture conditions and then were harvested at selected time points as single CSs. CS detachment was achieved simply by lowering the external temperature below the T of MC. The detached CSs displayed adhesive and proliferative activity when transferred to new plastic culture surfaces, indicating a high potential for regenerative purposes.
Lorenzo Bonetti, Luigi De Nardo, Silvia Farè

1462 related Products with: Chemically Crosslinked Methylcellulose Substrates for Cell Sheet Engineering.

500 ml10 lt50 ml10 ml50 ml10 ml 5 lt500 ml

Related Pathways

paperclip

#34563024   2021/09/10 To Up

Ovarian Cell Encapsulation in an Enzymatically Crosslinked Silk-Based Hydrogel with Tunable Mechanical Properties.

An artificial ovary is a promising approach for preserving fertility in prepubertal girls and women who cannot undergo current cryopreservation strategies. However, this approach is in its infancy, due to the possible challenges of creating a suitable 3D matrix for encapsulating ovarian follicles and stromal cells. To maintain the ovarian stromal cell viability and proliferation, as a first step towards developing an artificial ovary, in this study, a double network hydrogel with a high water swelling capacity (swelling index 15-19) was developed, based on phenol conjugated chitosan (Cs-Ph) and silk fibroin (SF) through an enzymatic crosslinking method using horseradish peroxidase. The addition of SF (1%) to Cs (1%) decreased the storage modulus (G') from 3500 Pa (Cs1) to 1600 Pa (Cs-SF1), and the hydrogels with a rapid gelation kinetic produced a spatially homogeneous distribution of ovarian cells that demonstrated 167% proliferation after 7 days. This new Cs-SF hydrogel benefits from the toughness and flexibility of SF, and phenolic chemistry could provide the potential microstructure for encapsulating human ovarian stromal cells.
Hafez Jafari, Arezoo Dadashzadeh, Saeid Moghassemi, Payam Zahedi, Christiani A Amorim, Amin Shavandi

2273 related Products with: Ovarian Cell Encapsulation in an Enzymatically Crosslinked Silk-Based Hydrogel with Tunable Mechanical Properties.

100ug Lyophilized2 Pieces/Box100ug Lyophilized100ug Lyophilized100ug Lyophilized100ug Lyophilized2 Pieces/Box1 mL

Related Pathways

paperclip

#34563020   2021/09/07 To Up

Fine-Tuning of Molecular Structures to Generate Carbohydrate Based Super Gelators and Their Applications for Drug Delivery and Dye Absorption.

Carbohydrate-based low molecular weight gelators (LMWGs) exhibit many desirable properties making them useful in various fields including applications as drug delivery carriers. In order to further understand the structural connection to gelation properties, especially the influence of halide substitutions, we have designed and synthesized a series of -chlorobenzylidene acetal protected D-glucosamine amide derivatives. Fifteen different amides were synthesized, and their self-assembling properties were assessed in multiple organic solvents, as well as mixtures of organic solvents with water. All derivatives were found to be gelators for at least one solvent and majority formed gels in multiple solvents at concentrations lower than 2 wt%. A few derivatives rendered remarkably stable gels in aqueous solutions at concentrations below 0.1 wt%. The benzamide formed gels in water and in EtOH/HO (/ 1:2) at 0.36 mg/mL. The gels were characterized using optical microscopy and atomic force microscopy, and the self-assembly mechanism was probed using variable temperature H-NMR spectroscopy. Gel extrusion studies using HO/DMSO gels successfully printed lines of gels on glass slides, which retained viscoelasticity based on rheology. Gels formed by the benzamide were used for encapsulation and the controlled release of chloramphenicol and naproxen, as well as for dye removal for toluidine blue aqueous solutions.
Jonathan Bietsch, Mary Olson, Guijun Wang

2777 related Products with: Fine-Tuning of Molecular Structures to Generate Carbohydrate Based Super Gelators and Their Applications for Drug Delivery and Dye Absorption.

50 ug 100ul100ug200ul10 mg25 µg100 mg 25 MG5mg25 µg100ul25 mg

Related Pathways

paperclip

#34563015   2021/08/29 To Up

Molecular Simulation and Theoretical Analysis of Slide-Ring Gels under Biaxial Deformation.

S
Kotaro Tanahashi, Tsuyoshi Koga

2945 related Products with: Molecular Simulation and Theoretical Analysis of Slide-Ring Gels under Biaxial Deformation.

10 ug1 module96T16 Arrays/Slide100ul5mg1 module1 module50 mg4 Arrays/Slide

Related Pathways

    No related Items
paperclip

Error loading info... Pleas try again later.
paperclip

#34562931   2021/09/16 To Up

Genetically Encoded Sensor Cells for the Screening of Glucocorticoid Receptor (GR) Effectors in Herbal Extracts.

A
Chungwon Kang, Soyoun Kim, Euiyeon Lee, Jeahee Ryu, Minhyeong Lee, Youngeun Kwon

2617 related Products with: Genetically Encoded Sensor Cells for the Screening of Glucocorticoid Receptor (GR) Effectors in Herbal Extracts.

100 μg100 assays2 Pieces/Box-100ug Lyophilized100 assays100ug100ug100ug Lyophilized96T

Related Pathways

    No related Items
paperclip

#34562930   2021/09/15 To Up

FLIM-Based Intracellular and Extracellular pH Measurements Using Genetically Encoded pH Sensor.

T
Alexander S Goryashchenko, Alexey A Pakhomov, Anastasia V Ryabova, Igor D Romanishkin, Eugene G Maksimov, Alexander N Orsa, Oxana V Serova, Andrey A Mozhaev, Margarita A Maksimova, Vladimir I Martynov, Alexander G Petrenko, Igor E Deyev

2394 related Products with: FLIM-Based Intracellular and Extracellular pH Measurements Using Genetically Encoded pH Sensor.

Two 96-Well Microplate KiOne 96-Well Microplate Ki100ugOne 96-Well Microplate Ki50 ug One 96-Well Microplate KiOne 96-Well Microplate KiTwo 96-Well Microplate Ki50 ug One 96-Well Microplate Ki500 testsOne 96-Well Microplate Ki

Related Pathways

    No related Items