Article
Biochemistry & Molecular Biology
Jing-Kun Yan, Zi-Wei Wang, Jie Zhu, Yujia Liu, Xu Chen, Lin Li
Summary: This study successfully developed a new method for encapsulating curcumin using polyelectrolyte nanoparticles. Compared with free curcumin, curcumin loaded in the nanoparticles demonstrated improved performance, including better redispersion, thermal stability, photostability, and sustained release.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2022)
Article
Polymer Science
Giuseppe Rosario Del Sorbo, Viviana Cristiglio, Daniel Clemens, Ingo Hoffmann, Emanuel Schneck
Summary: Aqueous mixtures of polyelectrolytes and oppositely charged surfactants can form clear and homogeneous solutions when one component is in excess, but macroscopic precipitates are formed around charge equilibrium. Near the phase boundary, nanometric polyelectrolyte/surfactant complexes can greatly increase the viscosity of aqueous solutions, governed by the composition and chemical nature of the polyelectrolyte and surfactant. The interaction between polycation JR 400 and sodium tetradecyl sulfate (STS) leads to a significant increase in viscosity, while no such increase is observed with sodium octyl sulfate (SOS) due to the absence of mixed aggregates.
Article
Polymer Science
Christian Aponte-Rivera, Michael Rubinstein
Summary: This study presents a scaling theory to predict the dynamics of symmetric and asymmetric unentangled liquid coacervates formed by solutions of oppositely charged polyelectrolytes. Symmetric coacervates consist of polycations and polyanions with equal charge densities and a single correlation length, while asymmetric coacervates have unequal charge densities and a double semidilute structure with two correlation lengths. The dynamic coupling in asymmetric coacervates increases the friction and contribution to zero-shear viscosity of high-charge-density polyelectrolytes, with a non-monotonic salt concentration dependence of the zero-shear viscosity predicted.
Article
Chemistry, Multidisciplinary
Sofia M. Morozova, Leticia Lopez-Flores, Albert Gevorkian, Honghu Zhang, Vahid Adibnia, Weiqing Shi, Dmytro Nykypanchuk, Tatiana G. Statsenko, Gilbert C. Walker, Oleg Gang, Monica Olvera de la Cruz, Eugenia Kumacheva
Summary: Particle softness plays an important role in the formation of colloidal clusters and gels. Experimental and simulation studies were conducted to investigate the impact of particle softness on the assembly of clusters and networks from mixtures of oppositely charged polymer nanoparticles. It was found that hard nanoparticles formed fractal clusters and subsequently organized into a kinetically arrested colloidal gel, while soft nanoparticles formed dense precipitating aggregates. Moreover, interactions between hard and soft nanoparticles resulted in the formation of discrete precipitating aggregates at a relatively low volume fraction of soft nanoparticles.
Article
Chemistry, Physical
Revaz Chachanidze, Kaili Xie, Hanna Massaad, Denis Roux, Marc Leonetti, Clement de Loubens
Summary: Controlling the assembly of polyelectrolytes and surfactant at liquid-liquid interfaces is important for fabricating soft materials with specific physical properties. The kinetics and properties of the assembly process of a positively charged biopolymer, chitosan, with an anionic fatty acid at the water-oil interface were studied. The results revealed that the interfacial complexation is a multi-step process.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Physical
Monika Bak, Judith Mihaly, Gergo Gyulai, Istvan Szalai, Imre Varga, Robert Meszaros
Summary: Experiments revealed the formation of solid films at liquid interfaces through the interfacial association of anionic polyelectrolytes and surfactants. These films possess temperature sensitivity and offer an alternative to previously synthesized solid polyion/surfactant assemblies.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Review
Physics, Condensed Matter
Eduardo Guzman, Armando Maestro, Francisco Ortega, Ramon G. Rubio
Summary: The association of polyelectrolytes and surfactants with opposite charges has traditionally been considered under an equilibrium framework. However, this does not accurately describe the physico-chemical rules of the association process when kinetically arrested nonequilibrium states are formed. The specific interaction pathways between the polyelectrolyte chains and surfactant molecules are determined by the mixing procedure and mixture composition, which can induce local inhomogeneities and drive the system away from true equilibrium. This topical review aims to provide a general perspective on the role of nonequilibrium aspects in controlling the polyelectrolyte-surfactant association process and their impact on the properties of supramolecular nanoassemblies.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Marek Bekir, Anja Hoermann, Christoph Brueckner, Ingo Hoffmann, Sylvain Prevost, Michael Gradzielski
Summary: Nanoparticles have the potential for biological applications due to their size-dependent properties, with interactions with phospholipid membranes being crucial. While electrostatic attraction favors binding, the presence of a polymer layer drastically reduces the binding rate.
Review
Pharmacology & Pharmacy
Ritesh Kumar Tiwari, Lalit Singh, Vaibhav Rastogi
Summary: Polyelectrolyte complexes (PECs) are adaptable constructs formed by electrostatic interaction between biopolymers with inverse charges, with significant advancements in new drug delivery systems.
CURRENT DRUG DELIVERY
(2021)
Article
Chemistry, Multidisciplinary
Thi Hai Yen Doan, Voon Huey Lim, Yasuhisa Adachi, Tien Duc Pham
Summary: The effects of ionic strength on the adsorption of highly charged polycationic onto polystyrene sulfate latex particles were investigated, revealing that the thickness of the adsorbed layer increased more at lower ionic strength in the presence of polyanions. Electrophoretic mobility remained unchanged or increased over time, depending on the concentration ratio of the two polyelectrolytes.
Article
Biochemistry & Molecular Biology
Nairiti J. Sinha, Keila Cristina Cunha, Robert Murphy, Craig J. Hawker, Joan-Emma Shea, Matthew E. Helgeson
Summary: Biomolecular assembly processes involve competition between specific interactions and phase instability. Aqueous mixtures of oppositely charged homochiral polypeptides can form solid-like precipitates or liquid-like coacervate droplets depending on hydrogen bonding interactions. Polypeptide mixtures exhibit diverse morphologies including partially coalescing and aggregated droplets, bulk precipitates, and a re-entrant liquid-liquid phase separation. The concentration dependence of beta-sheet-rich secondary structure correlates with the observed morphologies.
Article
Chemistry, Multidisciplinary
Mohsen Ghasemi, Sumanth N. Jamadagni, Eric S. Johnson, Ronald G. Larson
Summary: In order to design personal care formulations more effectively, we have developed a molecular thermodynamic model that can predict the formation of coacervates from cationic polymers and mixed micelles containing neutral and anionic surfactants with added salt. The coacervates formed by dilution of conditioning shampoos during use can provide conditioning agents, actives, and lubrication benefits to the scalp or skin. Our model takes into account various factors such as mixing entropy, hydrophobic interactions, binding energies, and electrostatic interactions. By studying the effects of different compositions and charge fractions, we were able to validate our model with experimental data and compare the coacervation behavior of different systems.
Article
Physics, Condensed Matter
Susmita Ghosh, Satyavani Vemparala
Summary: Extensive molecular dynamics simulations were used to investigate the collapse kinetics of a single flexible polyelectrolyte (PE) chain under poor solvent conditions. The charged nature of the PE chain and the valency of counterions were found to significantly affect the collapse kinetics. The behavior of charged polymers differed from that of neutral polymers, and the finite-size scaling of PE collapse times did not follow the Rouse scaling observed for neutral polymers. The coarsening of clusters along the PE chain suggested a multi-stage collapse with opposite exponents compared to neutral polymers.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Gulnara A. Ahmadova, Ravan A. Rahimov, Z. Abilova, Khuraman A. Huseynova, Elmar Imanov, Fedor I. Zubkov
Summary: This study investigated the interaction between cationic surfactants and anionic polyelectrolytes in aqueous media, evaluating various parameters such as surface tension, surface pressure, and adsorption efficiency. Thermodynamic parameters were calculated, and the influence of the nature of the head-groups on the colloidal properties of the complexes was compared. Additionally, the ability of these complexes to collect oil in waters of different mineralization degrees was examined.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Physical
Lester C. Geonzon, Motoyoshi Kobayashi, Takuya Sugimoto, Yasuhisa Adachi
Summary: The adsorption kinetics of polyelectrolytes on a single particle were investigated, showing that the charge density and salt concentration have an impact on the adsorption behavior. The adsorption process of cationic polyelectrolytes is controlled by attractive interactions, while the adsorption of anionic polyelectrolytes is influenced by repulsion between charged segments and the particle surfaces.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Jiayun Han, Rintaro Takahashi, Chen Kuang, Takahiro Sato
Summary: The study investigated the phase-separating properties of aqueous PNIPAM solution, revealing a temperature-dependent relationship between droplet size and heating rate.
Article
Polymer Science
Rintaro Takahashi, Theyencheri Narayanan, Shin-ichi Yusa, Takahiro Sato
Summary: This study reports the self-assembly kinetics of polymer vesicles probed by time-resolved small-angle scattering. The formation process of polymer vesicles was found to exhibit different kinetic behavior compared to conventional low-molecular-weight surfactants. This finding is significant for understanding the formation mechanism of polymer vesicles.
Article
Chemistry, Physical
Thomas Zinn, Lewis Sharpnack, Theyencheri Narayanan
Summary: The orientation behavior and translational dynamics of spherical magnetic silica-nickel Janus colloids in an external magnetic field have been studied. The research findings reveal that the particle dynamics is dominated by Brownian motion for weak applied fields and low volume fractions. However, higher fields result in more complex structural changes and chain-like configurations. The study also demonstrates anisotropic particle dynamics at higher volume fractions and strong magnetic fields.
Article
Polymer Science
Yoko Mizoue, Rintaro Takahashi, Kazuo Sakurai, Shin-ichi Yusa
Summary: An amphiphilic diblock copolymer (PChM-PNIPAM) was synthesized and it demonstrated liquid crystalline behavior and a lower critical solution temperature (LCST) due to the poly(cholesteryl 6-methacryloyloxy hexanoate) (PChM) and poly(N-isopropyl acrylamide) (PNIPAM) blocks it contained. PChM-PNIPAM formed water-soluble polymer micelles through hydrophobic interactions below the LCST. The core and hydrophilic shell of the micelles were formed by the PChM and PNIPAM blocks, respectively. Increasing temperature caused a liquid crystalline phase transition in the core and dehydration of the PNIPAM block in the shell, leading to inter-micellar aggregation above the LCST.
Article
Chemistry, Physical
Lauren Matthews, Theyencheri Narayanan
Summary: This article presents the recent progress of synchrotron scattering methods for elucidating the self-assembly pathways in dilute surfactant systems. The improved source brilliance and advanced detectors enable time-resolved structural investigations of low contrast and dilute surfactant solutions in the millisecond range. The results demonstrate that spontaneous self-assembly occurs in dilute solutions without any pre-existing motifs.
COLLOID AND POLYMER SCIENCE
(2023)
Article
Chemistry, Physical
Anja F. Hoermann, Artem Feoktystov, Theyencheri Narayanan, Jeremie Gummel, Michael Gradzielski
Summary: A quantitative analysis of small-angle x-ray scattering on a mixed surfactant system of tetradecyldimethylamine oxide (TDMAO) and lithium perfluorooctanoate (LiPFO) was conducted using densitometry, conductimetry, and contrast-variation small-angle neutron scattering. The study found that the vesicles formed contained a higher mole fraction of TDMAO than predicted by Regular Solution Theory (RST), and the unimer concentration of LiPFO was significantly higher than predicted by RST. Additionally, the vesicle bilayer was asymmetric with a higher fraction of LiPFO on the outside. These findings are important for understanding similar mixed surfactant vesicle systems and their applications.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Shukanta Bhowmik, Thu Thao Pham, Rintaro Takahashi, Dongwook Kim, Hideki Matsuoka, Kazuhiko Ishihara, Shin-ichi Yusa
Summary: Cationic random copolymers and anionic random copolymers were prepared using a reversible addition-fragmentation chain transfer method. The copolymers were mixed to form water-soluble polyion complex micelles, with MPC-rich surface and MCC/MPS core. The size of these micelles depended on the mixing ratio of the oppositely charged copolymers.
Article
Polymer Science
Tatsuya Mizuno, Mikihiro Hayashi, Rintaro Takahashi
Summary: This study analyzes the unique tensile properties of acrylate elastomers prepared using macro cross-linker polymers with multiple vinyl side groups. The macro cross-linker is prepared by synthesizing poly(ethyl acrylate) copolymers with hydroxy functional groups, followed by a hydroxy-isocyanate reaction. Elastomer samples are then prepared by UV polymerization of ethyl acrylate. The results reveal that the stress upturn in the large elongation region varies based on the fraction of vinyl side groups in the macro cross-linkers, while stress in the small elongation region remains unchanged.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
Riku Yamanaka, Ayae Sugawara-Narutaki, Rintaro Takahashi
Summary: The polymerization of solvophobic monomers from both ends of solvophilic polymers produces BAB triblock copolymers in solution, which can lead to network formation and gelation through the self-assembly of the extending solvophobic blocks. This polymerization-induced self-assembly (PISA) process in triblock copolymers is of significant interest, but its underlying mechanism has been poorly understood compared to that of PISA in diblock copolymers. In this study, the PISA and gelation process of triblock copolymers were monitored for the first time using two independent in situ time-resolved techniques - small-angle X-ray scattering and oscillatory rheology. It was discovered that the gelation proceeds instantaneously after an induction period and is distinct from conventional gelation processes involving polycondensation or cross-linking reactions of polymers. This study sheds light on the entire process of PISA and network formation during the synthesis of triblock copolymers.
Article
Chemistry, Multidisciplinary
Theyencheri Narayanan, William Chevremont, Thomas Zinn
Summary: Recently, fourth-generation synchrotron sources with higher brightness and coherence compared to previous sources have opened up new possibilities for small-angle X-ray scattering (SAXS) and X-ray photon correlation spectroscopy (XPCS). These advancements in beam properties and detector technology have improved the angular resolution and enabled the probing of equilibrium dynamics over broader scales. This article showcases the performance of SAXS and XPCS using the Extremely Brilliant Source at the European Synchrotron Radiation Facility, while also addressing the challenge of radiation damage in sample analysis.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2023)
Article
Chemistry, Multidisciplinary
Angelo Pommella, Pablo Griffiths, Gildas Coativy, Florent Dalmas, Surojit Ranoo, Annette M. M. Schmidt, Francoise Mechin, Julien Bernard, Thomas Zinn, Theyencheri Narayanan, Sylvain Meille, Guilhem P. P. Baeza
Summary: By investigating the heating mechanism in multi-block copolymers filled with Fe nanoparticles and subjected to an oscillatory magnetic field, the physical origin of the secondary heating mechanism in magnetic hyperthermia is revealed. It is found that the enormous drop of viscosity at the polymer melting temperature enables motion of nanoparticles that generates additional heat through friction.
Article
Physiology
Marco Caremani, Luca Fusi, Massimo Reconditi, Gabriella Piazzesi, Theyencheri Narayanan, Malcolm Irving, Vincenzo Lombardi, Marco Linari, Elisabetta Brunello
Summary: Skeletal muscle contraction is triggered by an increase in intracellular calcium concentration. The release of folded motors and the conformation of thick filaments are both influenced by calcium. A new intermediate regulatory state of myosin motors appears at low levels of calcium activation.
JOURNAL OF GENERAL PHYSIOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Rintaro Takahashi, Kazuki Yamamoto, Ryo Sugahara, Ryusuke Otake, Keisuke Hayashi, Jin Nakamura, Chikara Ohtsuki, Sadahito Aoshima, Ayae Sugawara-Narutaki
Summary: Block copolymer-mediated self-assembly can induce the formation of ring-like nanostructures from colloidal nanoparticles. Previous studies have shown that silica nanoparticles can assemble into ring-like structures in the presence of temperature-responsive block copolymer PEOVE-PMOVE. In this work, we demonstrate that silica nanoparticles can also form ring-like structures with a different temperature-responsive block copolymer PPO-PEO.
Article
Polymer Science
Kengo Takagi, Shukanta Bhowmik, Kang-Ting Huang, Chun-Jen Huang, Rintaro Takahashi, Shin-ichi Yusa
Summary: Excess copper accumulation in the body can cause various health problems. This study synthesized a copolymer (P(MPC/LysA)) with the potential to remove excess copper in the body. The copolymer exhibited a zwitterionic structure at physiological pH and formed water-soluble aggregates with copper ions.
Article
Chemistry, Multidisciplinary
A. Gibaud, D. Younas, L. Matthews, T. Narayanan, K. Longkaew, I. U. Hageberg, Y. Chushkin, D. W. Breiby, B. Chattopadhyay
Summary: The formation of calcium carbonate (CaCO3) nanoparticles in the presence of polystyrene sulfonate (PSS) additive was studied using time-resolved small-angle X-ray scattering in a flow system that mimics home experimental conditions. It was found that the concentration of precursors at a fixed PSS concentration plays a key role in determining the size of the obtained nanoparticles. Wide-angle X-ray scattering experiments showed that the formed particles have the structure of vaterite.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2023)
