scholarly journals Stimuli-Responsive Nucleotide–Amino Acid Hybrid Supramolecular Hydrogels

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 146
Author(s):  
Matthew Mulvee ◽  
Natasa Vasiljevic ◽  
Stephen Mann ◽  
Avinash J. Patil
Keyword(s):  
Mechanical Properties ◽  
Amino Acid ◽  
Self Assembly ◽  
Soft Materials ◽  
Guanosine Monophosphate ◽  
Molar Ratio ◽  
Stimuli Responsive ◽  
Molar Ratios ◽  
Hybrid Hydrogels ◽  
Guanine Residue

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.

Systematic evaluation of pH and thermoresponsive poly(n-isopropylacrylamide-chitosan-fluorescein) microgel

e-Polymers ◽  
2017 ◽  
Vol 17 (5) ◽  
pp. 399-408 ◽  
Author(s):  
Pedro Hernández ◽  
Armando Lucero-Acuña ◽  
Cindy Alejandra Gutiérrez-Valenzuela ◽  
Ramón Moreno ◽  
Reynaldo Esquivel
Keyword(s):  
Biomedical Application ◽  
Systematic Evaluation ◽  
Molar Ratio ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
Stimuli Responsive Polymers ◽  
Wide Range ◽  
Low Molecular Weight Chitosan

AbstractThe interesting properties of stimuli-responsive polymers lead to a wide range of possibilities in design and engineering of functional material for the biomedical application. A systematic approach focused on the evaluation of the physical properties of multiresponse (pH and temperature) PNIPAM was reported in this work. The effect of three different molar ratios of poly(n-isopropylacrylamide): chitosan (1:49, 1:99 and 1:198) were evaluated and labeled correspondingly as PC1F, PC2F, and PC3F. An increase in the lower critical solution temperature (LCST) of sample PC1F (34°C) was observed by differential scanning calorimetry (DSC). The presence of low molecular weight chitosan (LMWC) full-interpenetrating polymer (Full-IPN) segments in poly(n-isopropylacrylamide) was confirmed by Fourier-transform infrared spectroscopy (FT-IR). The hydrogel’s water capture was analyzed by two models of swelling, the power law model and a model that considers the relaxation of polymeric chains of the hydrogel, finding good correlations with experimental data in both cases. Sample PC3F resulted with higher swellability, increasing the weight of the hydrogel around seven times. Hydrogel pH-sensibility was confirmed placing the samples at different pH environments, with an apparent increase in swellability for acidic conditions, confirming the highest swellability for sample PC3F, due to hydrogen bonds boosted by chitosan high molar ratio. Based on these results, the hydrogel obtained has potential as a thermo-pH triggered hydrogel in drug delivery applications.

STM STUDY OF A SELF-ASSEMBLY BEHAVIOR OF PHTHALOCYANINE AND 1-BROMOHEXADECANE ON HIGHLY ORIENTED PYROLYTIC GRAPHITE

2006 ◽  
Vol 05 (06) ◽  
pp. 877-882
Author(s):  
WU YANG ◽  
WEILIAN LV ◽  
LILI BO ◽  
XIAOYAN HE ◽  
GANG NI ◽  
...  
Keyword(s):  
Self Assembly ◽  
Substrate Surface ◽  
Pyrolytic Graphite ◽  
Molar Ratio ◽  
Highly Oriented Pyrolytic Graphite ◽  
Molar Ratios ◽  
Molecular Features ◽  
Planar Molecules ◽  
Assembly Behavior ◽  
Stm Images

In this paper, we present the results of using alkane derivatives to assist in the adsorption of planar molecules by employing 1-bromohexadecane( C 16 Br ) and phthalocyanine (Pc) as examples. Their assembly behaviors have been well resolved on the observed STM images. The observations presented in this work demonstrate that single molecular arrays of Pc can be obtained with a template of C 16 Br on highly oriented pyrolytic graphite (HOPG) substrate surface to allow high-resolution STM studies. Binary mixtures of different molar ratios were also observed. By adjusting the molar ratio of Pc to C 16 Br to about 1:3–1:4, uniform assembly can become dominative on the surface. The resulting high stability and the well ordered assembly are attributed to the increased adsorption barrier of alkanes. This approach could be adapted to the studies of other molecules to observe molecular features and could be helpful in obtaining two-dimensional assemblies of monodispersed molecules, especially planar molecules.

scholarly journals Peptide:glycosaminoglycan hybrid hydrogels as an injectable intervention for spinal disc degeneration

2016 ◽  
Vol 4 (19) ◽  
pp. 3225-3231 ◽  
Author(s):  
D. E. Miles ◽  
E. A. Mitchell ◽  
N. Kapur ◽  
P. A. Beales ◽  
R. K. Wilcox
Keyword(s):  
Mechanical Properties ◽  
Disc Degeneration ◽  
Self Assembly ◽  
Hybrid Gels ◽  
Hybrid Hydrogels ◽  
Spinal Disc

Peptide and glycosaminoglycan hybrid gels undergo self-assembly and result in tuneable mechanical properties with suitability for intradiscal treatments.

Nanoscale metallogel via self-assembly of self-assembled trinuclear coordination rings: multi-stimuli-responsive soft materials

2015 ◽  
Vol 44 (34) ◽  
pp. 15181-15188 ◽  
Author(s):  
Sudhakar Ganta ◽  
Dillip Kumar Chand
Keyword(s):  
Self Assembly ◽  
Soft Materials ◽  
The Self ◽  
Stimuli Responsive ◽  
Self Assembled

A multi-stimuli-responsive metallogel is obtained by the self-assembly of an already self-assembled trinuclear palladium(ii) based coordination ring of the rare M3L6 composition.

The Effect of Zinc to Aluminium Molar Ratio on the Physico-Chemical Properties of Zinc-Aluminium-3,4-Dichlorophenoxy Acetate Nanocomposite

2013 ◽  
Vol 756 ◽  
pp. 127-134
Author(s):  
Sheikh Ahmad Izaddin Sheikh Mohd Ghazali ◽  
Mohd Zobir Hussein ◽  
Siti Halimah Sarijo
Keyword(s):  
Layered Double Hydroxide ◽  
Mole Fraction ◽  
Self Assembly ◽  
Chemical Properties ◽  
Zinc Ion ◽  
Molar Ratio ◽  
Basal Spacing ◽  
Molar Ratios ◽  
Assembly Method ◽  
Double Hydroxide

Layered double hydroxide (LDH) hybrid materials of Zn-Al-layered double hydroxide-3,4-dichlorophenoxy acetate acidnanocomposites (ZADs) were prepared by direct self-assembly method. The pH of the solution was adjusted to 7.5 using 2M NaOH. Various Zn2+ to Al3+ molar ratios, R ranging from 1 to 6 were used with a fixed concentration of 3,4-D at 0.3 M. The Powder X-ray diffraction (PXRD) patterns showed the formation of well-ordered nanocomposite with the expansion of basal spacing from 8.9 Å in the Zinc-Aluminium-Layered Double Hydroxide (ZAL) to 18.7 - 22.1 Å in the resulting nanocomposites. The Fourier transform infrared (FTIR)spectra for the nanocomposites showed features for both ZAL and ZAD, showing the successful intercalation of the organic moiety into the LDH interlayer. The percentage loading of 3,4-dichlorophenoxy acetati acid(3,4-D) in LDH was found to be increased from 34.7-48.1 % (w/w), as the mole fraction of Al decreased from 0.44-0.15. This study shows that the mole fraction of zinc ion was replaced by aluminium ion in the LDH plays an important role in controlling the physic-chemical properties of the resulting material.

Hierarchical self-assembly of amino acid derivatives into stimuli-responsive luminescent gels

Soft Matter ◽  
2014 ◽  
Vol 10 (41) ◽  
pp. 8261-8266 ◽  
Author(s):  
Yibao Li ◽  
Linxiu Cheng ◽  
Chunhua Liu ◽  
Yunzhi Xie ◽  
Wei Liu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Amino Acid Derivatives ◽  
Stimuli Responsive

Theoretical insight into the cocrystal explosive of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20)/1-Methyl-4,5-dinitro-1H-imidazole (MDNI)

2017 ◽  
Vol 16 (07) ◽  
pp. 1750061 ◽  
Author(s):  
Chunlei Wu ◽  
Shuhai Zhang ◽  
Fude Ren ◽  
Ruijun Gou ◽  
Gang Han
Keyword(s):  
Mechanical Properties ◽  
Density Functional ◽  
High Energy ◽  
High Energy Density ◽  
Molar Ratio ◽  
Detonation Pressure ◽  
Oxygen Balance ◽  
Molar Ratios ◽  
Surface Electrostatic Potentials ◽  
Low Sensitivity

Cocrystal explosive is getting more and more attention in high energy density material field. Different molar ratios of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20)/1-Methyl-4,5-dinitro-1H-imidazole (MDNI) cocrystal were studied by molecular dynamics (MD) simulation and quantum-chemical density functional theory (DFT) calculation. Binding energy of CL-20/MDNI cocrystal and radial distribution function (RDF) were used to estimate the interaction. Mechanical properties were calculated to predict the elasticity and ductility. The length and bond dissociation energy of trigger bond, surface electrostatic potentials (ESP) of CL-20/MDNI framework were calculated at B3LYP/6-311[Formula: see text]G(d,p) level. The results indicate that CL-20/MDNI cocrystal explosive might have better mechanical properties and stability in a molar ratio 3:2. The N–NO2 bond becomes stronger upon the formation of intermolecular H-bonding interaction. The surface electrostatic potential further confirms that the sensitivity decreases in cocrystal explosive in comparison with that in isolated CL-20. The oxygen balance (OB), heat of detonation ([Formula: see text], detonation velocity ([Formula: see text] and detonation pressure ([Formula: see text] of CL-20/MDNI suggest that the CL-20/MDNI cocrystal possesses excellent detonation performance and low sensitivity.

Polymerization-induced self-assembly driving chiral nanostructured materials

2015 ◽  
Vol 6 (34) ◽  
pp. 6152-6162 ◽  
Author(s):  
Kamal Bauri ◽  
Amal Narayanan ◽  
Ujjal Haldar ◽  
Priyadarsi De
Keyword(s):  
Amino Acid ◽  
Nanostructured Materials ◽  
Self Assembly ◽  
Soft Materials ◽  
Morphological Transition ◽  
Group Transformation

Amino acid coated chiral nanostructured soft materials are made by the polymerization induced self-assembly (PISA) technique, where the post-polymerization chemical group transformation leads to a morphological transition.

scholarly journals Influence of Capping Groups on the Synthesis of γ-Fe2O3 Nanocrystals

2004 ◽  
Vol 19 (4) ◽  
pp. 1208-1215 ◽  
Author(s):  
Ming Yin ◽  
Amanda Willis ◽  
Franz Redl ◽  
Nicholas J. Turro ◽  
Stephen P. O’Brien
Keyword(s):  
Self Assembly ◽  
Carbon Chain ◽  
Iron Pentacarbonyl ◽  
Decomposition Temperature ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Nonpolar Solvents ◽  
Transmission Electron ◽  
Iron Precursor ◽  
Chain Lengths

Monodisperse and uniform γ-Fe2O3 (maghemite) nanocrystals of variable size were prepared by thermal decomposition of iron pentacarbonyl [Fe(CO)5] in the presence of surfactants, following controlled oxidation with trimethylamine N-oxide as a mild oxidant. The influence of carboxylic acids with variable alkyl carbon chain lengths on the synthesis of γ-Fe2O3 nanocrystals was investigated. The effect of the molar ratios of surfactant to iron precursor was also studied. The nanocrystals were characterized by x-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD showed the particles were highly crystalline at the nanometer scale. The results showed that the size and shape of the nanocrystal is strongly influenced by the decomposition temperature of iron pentacarbonyl and closely related to the length of carbon chain of the capping groups and the molar ratio of surfactant to iron precursor. Following controlled evaporation from nonpolar solvents, self-assembly into two-dimensional arrays could be observed by TEM. It was also found that the distance between the nanocrystals in self-assembled structures matched the length of the capping molecules very well.

scholarly journals Synthesis and Self-Assembly Properties of Bola-Amphiphilic Glycosylated Lipopeptide-Type Supramolecular Hydrogels Showing Colour Changes Along with Gel–Sol Transition

2021 ◽  
Vol 22 (4) ◽  
pp. 1860
Author(s):  
Naoki Tsutsumi ◽  
Akitaka Ito ◽  
Azumi Ishigamori ◽  
Masato Ikeda ◽  
Masayuki Izumi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Soft Materials ◽  
The Self ◽  
Low Molecular Weight ◽  
Stimuli Responsive ◽  
Short Peptide ◽  
Peptide Moiety ◽  
Colour Changes ◽  
Reversible Thermochromism ◽  
Significant Attention

Supramolecular hydrogels formed by self-assembly of low-molecular-weight amphiphiles (hydrogelators) have attracted significant attention, as smart and soft materials. However, most of the observed stimuli-responsive behaviour of these supramolecular hydrogels are limited to gel–sol transitions. In this study, we present bola-amphiphilic glycosylated lipopeptide-type supramolecular hydrogelators that exhibit reversible thermochromism along with a gel–sol transition. The bola-amphiphiles have mono-, di-, tri- or tetra-phenylalanine (F) as a short peptide moiety. We investigate and discuss the effects of the number of F residues on the gelation ability and the morphology of the self-assembled nanostructures.

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