Water soluble stimuli-responsive star copolymers with multiple encapsulation and release properties

RSC Advances ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. 8773-8785 ◽  
Author(s):  
Sandip Das ◽  
Dhruba P. Chatterjee ◽  
Radhakanta Ghosh ◽  
Pradip Das ◽  
Arun K. Nandi
Keyword(s):  
Water Soluble ◽  
Stimuli Responsive ◽  
Drug Molecule ◽  
Star Copolymers ◽  
Decreasing Ph ◽  
Increasing Temperature

Stimuli-responsive, water soluble, nontoxic, star-copolymers showing reversible encapsulation and release of hydrophobic dye/drug molecule with increasing temperature and decreasing pH.

Synthesis and supramolecular self-assembly of stimuli-responsive water-soluble Janus-type heteroarm star copolymers

Soft Matter ◽  
2009 ◽  
Vol 5 (20) ◽  
pp. 3932 ◽  
Author(s):  
Zhishen Ge ◽  
Jian Xu ◽  
Jinming Hu ◽  
Yanfeng Zhang ◽  
Shiyong Liu
Keyword(s):  
Self Assembly ◽  
Water Soluble ◽  
Stimuli Responsive ◽  
Star Copolymers

Smart Polymers and their Applications: A Review

2017 ◽  
Vol 8 (03) ◽  
Author(s):  
Gore S. A. ◽  
Gholve S. B. ◽  
Savalsure S. M. ◽  
Ghodake K. B. ◽  
Bhusnure O. G. ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Water Soluble ◽  
Solution Temperature ◽  
Smart Polymers ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Water Soluble Polymers ◽  
Commercial Applications ◽  
Stimuli Sensitive ◽  
External Stimuli

Smart polymers are materials that respond to small external stimuli. These are also referred as stimuli responsive materials or intelligent materials. Smart polymers that can exhibit stimuli-sensitive properties are becoming important in many commercial applications. These polymers can change shape, strength and pore size based on external factors such as temperature, pH and stress. The stimuli include salt, UV irradiation, temperature, pH, magnetic or electric field, ionic factors etc. Smart polymers are very promising applicants in drug delivery, tissue engineering, cell culture, gene carriers, textile engineering, oil recovery, radioactive wastage and protein purification. The study is focused on the entire features of smart polymers and their most recent and relevant applications. Water soluble polymers with tunable lower critical solution temperature (LCST) are of increasing interest for biological applications such as cell patterning, smart drug release, DNA sequencing etc.

Molecular, rheological and physicochemical characterisation of puka gum, an arabinogalactan-protein extracted from the Meryta sinclairii tree

2020 ◽  
Author(s):  
MSM Wee ◽  
Ian Sims ◽  
KKT Goh ◽  
L Matia-Merino
Keyword(s):  
Hydrodynamic Radius ◽  
Average Molecular Weight ◽  
Gum Arabic ◽  
Water Soluble ◽  
Arabinogalactan Protein ◽  
Type Ii ◽  
Weight Average Molecular Weight ◽  
Soluble Polysaccharide ◽  
Physicochemical Characterisation ◽  
Increasing Temperature

© 2019 Elsevier Ltd A water-soluble polysaccharide (type II arabinogalactan-protein) extracted from the gum exudate of the native New Zealand puka tree (Meryta sinclairii), was characterised for its molecular, rheological and physicochemical properties. In 0.1 M NaCl, the weight average molecular weight (Mw) of puka gum is 5.9 × 106 Da with an RMS radius of 56 nm and z-average hydrodynamic radius of 79 nm. The intrinsic viscosity of the polysaccharide is 57 ml/g with a coil overlap concentration 15% w/w. Together, the shape factor, p, of 0.70 (exponent of RMS radius vs. hydrodynamic radius), Smidsrød-Haug's stiffness parameter B of 0.031 and Mark-Houwink exponent α of 0.375 indicate that the polysaccharide adopts a spherical conformation in solution, similar to gum arabic. The pKa is 1.8. The polysaccharide exhibits a Newtonian to shear-thinning behaviour from 0.2 to 25% w/w. Viscosity of the polysaccharide (1 s−1) decreases with decreasing concentration, increasing temperature, ionic strength, and at acidic pH.

scholarly journals Thermo- and Photoresponsive Behaviors of Dual-Stimuli-Responsive Organogels Consisting of Homopolymers of Coumarin-Containing Methacrylate

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 329
Author(s):  
Seidai Okada ◽  
Eriko Sato
Keyword(s):  
Functional Group ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Equilibrium Degree ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Dual Functional ◽  
Wide Range ◽  
Increasing Temperature

Coumarin-containing vinyl homopolymers, such as poly(7-methacryloyloxycoumarin) (P1a) and poly(7-(2′-methacryloyloxyethoxy)coumarin) (P1b), show a lower critical solution temperature (LCST) in chloroform, which can be controlled by the [2 + 2] photochemical cycloaddition of the coumarin moiety, and they are recognized as monofunctional dual-stimuli-responsive polymers. A single functional group of monofunctional dual-stimuli-responsive polymers responds to dual stimuli and can be introduced more uniformly and densely than those of dual-functional dual-stimuli-responsive polymers. In this study, considering a wide range of applications, organogels consisting of P1a and P1b, i.e., P1a-gel and P1b-gel, respectively, were synthesized, and their thermo- and photoresponsive behaviors in chloroform were investigated in detail. P1a-gel and P1b-gel in a swollen state (transparent) exhibited phase separation (turbid) through a temperature jump and reached a shrunken state (transparent), i.e., an equilibrium state, over time. Moreover, the equilibrium degree of swelling decreased non-linearly with increasing temperature. Furthermore, different thermoresponsive sites were photopatterned on the organogel through the photodimerization of the coumarin unit. The organogels consisting of homopolymers of coumarin-containing methacrylate exhibited unique thermo- and photoresponsivities and behaved as monofunctional dual-stimuli-responsive organogels.

scholarly journals Thermo-Responsive Behavior of Mixed Aqueous Solution of Hydrophilic Polymer with Pendant Phosphorylcholine Group and Poly(Acrylic Acid)

Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 148
Author(s):  
Hirokazu Fukumoto ◽  
Kazuhiko Ishihara ◽  
Shin-Ichi Yusa
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Solution Temperature ◽  
Interpolymer Complex ◽  
Mixed Aqueous Solution ◽  
Upper Critical Solution Temperature ◽  
Acidic Conditions ◽  
Decreasing Ph ◽  
Increasing Temperature ◽  
Poly Acrylic Acid

A mixed aqueous solution of hydrophilic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly(acrylic acid) (PAAc) becomes cloudy under acidic conditions at room temperature. The pendant carboxylic acid groups in PAAc form hydrogen bonds with the ester and phosphate groups in PMPC. While the polymers aggregate under acidic conditions, neither one associate under basic conditions because of the deprotonation of the pendant carboxy groups in PAAc. We observed that the interpolymer complex formed from PMPC, and PAAc was dissociated in aqueous solutions with increasing temperature, which is an upper critical solution temperature behavior. With increasing temperature, the molecular motion increased to dissociate the interpolymer complex. The phase transition temperature increased with increasing polymer and salt concentrations, and with decreasing pH.

Triple-stimuli-responsive nanocontainers assembled by water-soluble pillar[5]arene-based pseudorotaxanes for controlled release

2016 ◽  
Vol 4 (16) ◽  
pp. 2819-2827 ◽  
Author(s):  
ChenDi Ding ◽  
Ying Liu ◽  
Ting Wang ◽  
JiaJun Fu
Keyword(s):  
Controlled Release ◽  
Water Soluble ◽  
Stimuli Responsive ◽  
Working Mechanism

Working mechanism of triple-stimuli-responsive nanocontainers: alkaline, acid and Zn2+ stimuli can open the advanced supramolecular nanovalves.

scholarly journals Effects of the Temperature and the pH on the Main Protease of SARS-CoV-2: A Molecular Dynamics Simulation Study

2021 ◽  
Vol 12 (6) ◽  
pp. 7239-7248
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Root Mean Square ◽  
Dynamics Simulation ◽  
Effect Of Temperature ◽  
Water Molecules ◽  
Mean Square ◽  
Main Protease ◽  
Decreasing Ph ◽  
Increasing Temperature

The novel coronavirus, recognized as COVID-19, is the cause of an infection outbreak in December 2019. The effect of temperature and pH changes on the main protease of SARS-CoV-2 were investigated using all-atom molecular dynamics simulation. The obtained results from the root mean square deviation (RMSD) and root mean square fluctuations (RMSF) analyses showed that at a constant temperature of 25℃ and pH=5, the conformational change of the main protease is more significant than that of pH=6 and 7. Also, by increasing temperature from 25℃ to 55℃ at constant pH=7, a remarkable change in protein structure was observed. The radial probability of water molecules around the main protease was decreased by increasing temperature and decreasing pH. The weakening of the binding energy between the main protease and water molecules due to the increasing temperature and decreasing pH has reduced the number of hydrogen bonds between the main protease and water molecules. Finding conditions that alter the conformation of the main protease could be fundamental because this change could affect the virus’s functionality and its ability to impose illness.

scholarly journals Photoproduction of nitric oxide in seawater

Ocean Science ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 135-148 ◽  
Author(s):  
Ye Tian ◽  
Gui-Peng Yang ◽  
Chun-Ying Liu ◽  
Pei-Feng Li ◽  
Hong-Tao Chen ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
North Pacific Ocean ◽  
Artificial Seawater ◽  
Natural Seawater ◽  
Factors Affecting ◽  
Decreasing Ph ◽  
Seawater Samples ◽  
Major Factors ◽  
Increasing Temperature ◽  
Increasing Trends

Abstract. Nitric oxide (NO) is a short-lived intermediate of the oceanic nitrogen cycle. However, our knowledge about its production and consumption pathways in oceanic environments is rudimentary. In order to decipher the major factors affecting NO photochemical production, we irradiated several artificial seawater samples as well as 31 natural surface seawater samples in laboratory experiments. The seawater samples were collected during a cruise to the western tropical North Pacific Ocean (WTNP, a N–S section from 36 to 2∘ N along 146 to 143∘ E with 6 and 12 stations, respectively, and a W–E section from 137 to 161∘ E along the Equator with 13 stations) from November 2015 to January 2016. NO photoproduction rates from dissolved nitrite in artificial seawater showed increasing trends with decreasing pH, increasing temperature, and increasing salinity. In contrast, NO photoproduction rates (average: 0.5±0.2×10-12 mol L−1 s−1) in the natural seawater samples from the WTNP did not show any correlations with pH, water temperature, salinity, or dissolved inorganic nitrite concentrations. The flux induced by NO photoproduction in the WTNP (average: 13×10-12 mol m−2 s−1) was significantly larger than the NO air–sea flux density (average: 1.8×10-12 mol m−2 s−1), indicating a further NO loss process in the surface layer.

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