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Triblock Copolymers

Riya Modi, Laxmikanta Khamari, Atanu Nandy, Saptarshi Mukherjee
We report the unfolding of the globular protein, Bovine Serum Albumin (BSA) induced by anionic surfactant sodium dodecyl sulfate (SDS) and subsequently monitored the refolding of this denatured BSA using triblock copolymers F127 and P123 through the formation of mixed micelles. Our study exclusively represents the reversibility of this unfolding-refolding process using pluronic triblock copolymers F127/P123 as refolding agents. We confirm the recovery of its native state from its denatured state estimating the α-helical structure of the denatured protein from the CD data which support our steady state fluorescence spectra monitoring the fluorescence of the intrinsic Trp molecules present in BSA...
March 6, 2019: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Jens Gaitzsch, Stephan Hirschi, Sven Freimann, Dimitrios Fotiadis, Wolfgang Peter Meier
Nanoscopic artificial vesicles containing functional protein transporters are fundamental for synthetic biology. Energy providing modules, such as proton pumps, are a basis for simple nanoreactors. We report on the first insertion of a functional transmembrane protein into asymmetric polymersomes from an ABC triblock-copolymer. The polymer with the composition poly(ethylene glycol)-poly(diisopropylaminoethyl methacrylate)-poly(styrene sulfonate) (PEG-PDPA-PSS) was synthesized by sequential controlled radical polymerization...
March 15, 2019: Nano Letters
Yan-Ling Yang, Yu-Jane Sheng, Heng-Kwong Tsao
HYPOTHESIS: Membranes formed by ABA (hydrophilic-hydrophobic-hydrophilic) triblock copolymers were studied. Bridge- and Loop-conformation of ABA copolymers are identified in the membrane and monolayered, bilayered, and mixed structured membranes can be formed. When lipids co-assemble with ABA copolymers, a hybrid membrane is developed. EXPERIMENTS: The monolayered (bridge-conformation) and bilayered membranes (loop-conformation) formed by ABA copolymers were investigated by dissipative particle dynamics, and their hybridization with lipids was studied as well...
February 22, 2019: Journal of Colloid and Interface Science
Prajakta Tambe, Pramod Kumar, Kishore M Paknikar, Virendra Gajbhiye
Recent interest in triblock dendritic unimolecular micelles has opened a new spectrum for its ubiquitous application in biomedical sciences specially drug delivery. Unimolecular dendritic micelles have brought significant attention due to their high encapsulation efficiency, high-functionality, and site specific confinement capabilities. During the last decade, the number of publications in this field has increased drastically, reinforced by the fact that several clinical trials are underway using micelles for drug delivery...
February 20, 2019: Journal of Controlled Release: Official Journal of the Controlled Release Society
Xu Liu, Chen-Gang Wang, Atsushi Goto
Molecular weight distribution of polymer, termed dispersity (Đ), is a fundamental key parameter for determining polymer material properties. This paper reports a novel approach for controlling Đ, exploiting a temperature-selective radical generation in organocatalyzed living radical polymerization. The polymers with tailored Đ were synthesized in a batch system without the assistance of an external pump. A unique aspect of this approach is that Đ was tuneable from 1.11 to 1.50 in any segments in diblock, triblock, and multi-block copolymers and any forms of star and brush polymers without segmental or topological restriction...
February 20, 2019: Angewandte Chemie
Justin P Cole, Celia R Federico, Chern-Hooi Lim, Garret M Miyake
Photoinduced organocatalyzed atom-transfer radical polymerization (O-ATRP) is a controlled radical polymerization methodology that can be mediated by organic photoredox catalysts under the influence of light. However, typical O-ATRP systems require relatively high catalyst loadings (1000 ppm) to achieve control over the polymerization. Here, new core-extended diaryl dihydrophenazine photoredox catalysts were developed for O-ATRP and demonstrated to efficiently operate at low catalyst loadings of 5-50 ppm to produce polymers with excellent molecular weight control and low dispersity, while achieving near-quantitative initiator efficiency...
January 22, 2019: Macromolecules
Jianhua Zhou, Yannan Li, Hong Li, Hongtao Yao
Cellulose nanocrystals/fluorinated polyacrylate soap-free emulsion was successfully synthesized via RAFT-assisted Pickering emulsion process using modified cellulose nanocrystals as particle stabilizers. The cellulose nanocrystals were organically modified by linear triblock copolymer poly(2-(dimethylamino) ethyl methacrylate)-b-poly(glycidyl methacrylate)-b-poly(2,2,3,4,4,4-Hexafluorobutyl acrylate) (PDMAEMA-b-PGMA-b-PHFBA) with reactive trithiocarbonate group. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses showed that modified cellulose nanocrystals were armored on the surface of spherical particles...
February 10, 2019: Colloids and Surfaces. B, Biointerfaces
Guansheng Zhong, Chuan Yang, Shaoqiong Liu, Yiran Zheng, Weiyang Lou, Jye Yng Teo, Chang Bao, Wei Cheng, Jeremy P K Tan, Shujun Gao, Nathaniel Park, Shrinivas Venkataraman, Yuan Huang, Min Han Tan, Xiaojia Wang, James L Hedrick, Weimin Fan, Yi Yan Yang
Although mortality continues to decline over the past two decades, cancer is still a pervasive healthcare problem worldwide due to the increase in the number of cases, multidrug resistance (MDR) and metastasis. As a consequence of multidrug resistance, cancer treatment must rely on a host of chemotherapeutic agents and chemosensitizers to achieve remission. To overcome these problems, a series of biodegradable triblock copolymers of PEG, guanidinium-functionalized polycarbonate and polylactide (PEG-PGCx -PDLAy ) is designed as chemotherapeutic agents...
January 25, 2019: Biomaterials
Shankar P Khatiwada, Uwe Gohs, Ralf Lach, Gert Heinrich, Rameshwar Adhikari
The work aims at establishing the optimum conditions for dual thermal and electron beam curing of thermosetting systems modified by styrene/butadiene (SB)-based triblock copolymers in order to develop transparent and toughened materials. The work also investigates the effects of curing procedures on the ultimate phase morphology and mechanical properties of these thermoset⁻SB copolymer blends. It was found that at least 46 mol% of the epoxidation degree of the SB copolymer was needed to enable the miscibility of the modified block copolymer into the epoxy resin...
February 12, 2019: Materials
Ruxi Dai, Paula L Diaconescu
A zirconium compound, (salfen)Zr(OiPr)2 (salfen = N,N'-bis(2,4-di-tert-butylphenoxy)-1,1'-ferrocenediimine), was tested as a redox switchable catalyst for the ring opening polymerization of cyclic esters and epoxides. Different activities were observed in the reduced and oxidized state, and an orthogonal switch on monomer activities could be achieved. Diblock and triblock copolymers were synthesized using an in situ redox switch of the catalyst oxidation state.
February 12, 2019: Dalton Transactions: An International Journal of Inorganic Chemistry
Yusheng Zhou, Haiyang Gao, Fangming Zhu, Mingliang Ge, Guodong Liang
A kind of self-stabilized micelles of fluorescent block copolymers are constructed for rapid and sensitive detection of aliphatic amines in water based on capture-report strategy. An amphiphilic triblock copolymer functionalized with aggregation induced emission (AIE) chromophores self assembles into micelles with core-shell structures in aqueous solution. Hydrophobic AIE chromophores organize into cores, where hydrophobic interaction among the AIE chromophores inhibits the micelles from disassembling. The cores of AIE chromophores are surrounded by a corona of water-soluble polymer segments, endowing the micelles with superior dispersibility in water...
January 30, 2019: Journal of Hazardous Materials
Yoshinori Arisaka, Nobuhiko Yui
Hepatocytes in vitro may be useful for treating various types of liver diseases, but these cells immediately lose their functions. Here, we designed sulfonated-polyrotaxane (PRX) surfaces with immobilized heparin binding-epidermal growth factor-like growth factors (HB-EGFs) for improving hepatic functions. Sulfonated-PRX triblock copolymers, composed of sulfopropyl ether modified α-cyclodextrins (α-CDs) threaded onto a poly(ethylene glycol) (PEG) chain as a PRX segment and poly(benzyl methacrylate) at both terminals of the PEG as anchoring segments, were coated onto polystyrene surfaces by a drop cast method...
February 5, 2019: Journal of Biomedical Materials Research. Part A
Shiro Ishii, Shou Sakaue, Yukio Nagasaki
To provide sustained release of exenatide and enhance therapeutic efficacy for the treatment of type 2 diabetes compared to the existing products for exenatide, we developed an exenatide-loaded, redox-active, injectable gel (Exe@RIG). This injectable gel is formed by a polyion complex (PIC) comprising three components, (1) cationic polyamine-poly(ethylene glycol)-polyamine triblock copolymer possessing reactive oxygen species (ROS)-scavenging moieties as side chains, (2) anionic poly(acrylic acid), and (3) exenatide...
February 5, 2019: Journal of Biomedical Materials Research. Part A
Tingyao Zhou, Jiayi Zhu, Lingshan Gong, Liting Nong, Jinbin Liu
Assembling instable ultrasmall nanoparticles (NPs) into uniform nanoarchitectures with excellent stability and controllability in aqueous solution is still challenging. Herein, taking the advantage of controllable size and shape of amphiphilic triblock copolymer template, we report a facile and robust strategy for in-situ fabrication of highly luminescent Cu nanoassemblies with uniform morphology and remarkable stability. The dominant number of encapsulated CuNPs in an assembly can be controlled through regulating hydrophobic core size by varying block segments of the template...
February 4, 2019: Journal of the American Chemical Society
Hung-Hsun Lu, Cheng-Hung Huang, Ting-Yun Shiue, Fu-Sheng Wang, Ko-Kai Chang, Yunching Chen, Chi-How Peng
Triblock copolymer of poly(ethylene glycol)- b -poly(2-dimethylaminoethyl methacrylate)- b -poly(pyrenylmethyl methacrylate) (PEG- b -PDMAEMA- b -PPy) has been developed for use as an ideal gene delivery system, which showed both high stability under physiological conditions and efficient gene release in a mimetic cancer environment. The siRNA release from this system without external stimulation was 16% in 1 h and then remained steady. However, the photo-triggered siRNA release was 78% within 1 h and was higher than 91% after 24 h...
January 7, 2019: Chemical Science
Dinglingge Cao, Xingxian Zhang, M D Akabar, Yuan Luo, Hao Wu, Xue Ke, Tianyuan Ci
The aim of this research is to utilize a hybrid system of liposomal doxorubicin (DOX-Lip) loaded thermogel (DOX-Lip-Gel) to realize the steady sustained delivery of doxorubicin (DOX), a small hydrophilic drug, for the treatment of breast cancer locally. Herein, liposomal doxorubicin was prepared via the traditional film dispersion method with the particle size of 75 nm and drug entrapment efficiency of 86%. And, the triblock copolymer of poly (D, L-lactide-co-glycolide)-b-poly (ethylene glycol)-b-poly (D, L-lactide -co-glycolide) (PLGA-PEG-PLGA) was synthesized via ring-opening polymerization to prepare the thermosensitive hydrogel through dissolving the polymers in DOX-Lip solution...
December 2019: Artificial Cells, Nanomedicine, and Biotechnology
Elisamaria Tasca, Alessandra Del Giudice, Luciano Galantini, Karin Schillén, Anna Maria Giuliani, Mauro Giustini
HYPOTHESIS: Doxorubicin hydrochloride (DX) is one of the most powerful anticancer agents though its clinical use is impaired by severe undesired side effects. DX encapsulation in nanocarrier systems has been introduced as a mean to reduce its toxicity. Micelles of the nonionic triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) (PEO-PPO-PEO), are very promising carrier systems. The positive charge of DX confines the drug to the hydrophilic corona region of the micelles...
January 17, 2019: Journal of Colloid and Interface Science
Ivan Terzic, Niels L Meereboer, Mónica Acuautla, Giuseppe Portale, Katja Loos
A facile ferroelectric nanostructures preparation method is developed based on the self-assembly of poly(2-vinylpyridine)- b -poly(vinylidene fluoride- co -trifluoroethylene)- b -poly(2-vinylpyridine) triblock copolymers (P2VP- b -P(VDF-TrFE)- b -P2VP), and the effect of morphological characteristics of the block copolymers on the ferroelectric response has been investigated for the first time. By simple adjustment of the ratio between the blocks, lamellar, cylindrical, and spherical morphologies are obtained in the melt and preserved upon crystallization of P(VDF-TrFE)...
January 8, 2019: Macromolecules
Joseba Gomez-Hermoso-de-Mendoza, Hernane S Barud, Junkal Gutierrez, Agnieszka Tercjak
Transparent and flexible bionanocomposites with photochromic properties based on cellulose triacetate (CTA) and sol-gel synthesized V2 O5 nanoparticles were prepared. Poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (EPE) triblock copolymer was added to achieve nanostructured materials and simultaneously control the dispersion of synthesized V2 O5 nanoparticles. Investigated bionanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), atomic force microscopy (AFM), tensile tests, and UV-vis spectroscopy...
March 15, 2019: Carbohydrate Polymers
Sneha B Chakrapani, Michael J Minkler, Bryan S Beckingham
The accurate characterization of relative composition in multicomponent polymer systems such as statistical copolymers, block copolymers, and polymer blends is critical to understanding and predicting their behavior. Typically, polymer compositional analysis is performed using 1H Nuclear Magnetic Resonance (NMR) Spectroscopy which provides quantitative chemical group concentrations without prior calibration. This utility has led 1H NMR spectroscopy to become a routine method for the molecular characterization of polymers...
January 18, 2019: Analyst
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