Novel Fluoroalkyl End-Capped Amphiphilic Diblock Copolymers with pH/Temperature Response and Self-Assembly Behavior

Langmuir ◽  
2008 ◽  
Vol 24 (9) ◽  
pp. 4647-4654 ◽  
Author(s):  
Hu Zhang ◽  
Peihong Ni ◽  
Jinlin He ◽  
Cuicui Liu
2011 ◽  
Vol 345 ◽  
pp. 334-337
Author(s):  
Yong Zhou ◽  
Bing Liu

Novel chiral amphiphilic diblock copolymers bearing L-phenylalanine was synthesized using a “click” reaction of N3-L-phenylalanine and MPEO-b-PGPE. The structure and composition of copolymers were characterized by 1H-NMR and elemental analysis. Additionally, the self-assembly behavior of these chiral copolymers was investigated in sodium dihydrogen phosphate buffer (pH 4.5): the CMC of copolymer MPEO-b-PGTP determined by the measurement of surface tension was 2.1 mg/mL; the size and morphology of the micelles were studied using TEM; the specific optical rotation ([α]25D) of the micellar solutions was also measured; the result indicated that the copolymers can form chiral micelles in sodium dihydrogen phosphate buffer (pH =4.5).In recent years, the synthesis, structure and properties of optically active polymer have been paid attention by scientists owing to its potential applications in chiral separation, asymmetric adsorption, chiral synthesis[1]. The amphiphilic block polymers bearing amino acid possess not only the characteristics of the conventional amphiphilic block copolymer, but also good optically activity and biocompatibility. So it can be employed as nanoreactors for asymmetrical catalysis and materials for drug delivery. But there have been few reports published on the synthesis of chiral amphiphilic copolymers bearing amino acid. Sutthira Sutthasupa reported the synthesis of amino acid-based norbornene block copolymer with ester and carboxyl groups as hydrophobic and hydrophilic units[2]. O’Reilly group synthesized the amino acid-based chiral amphiphilic block copolymers using RAFT technique, and elucidated its self-assembly into spherical micelles with optically active hydrophobic core[3]. In the present work, chiral amphiphilic diblock copolymers bearing L-phenylalanine (L-Phe) pendants poly(ethylene oxide)-b-poly (glycidyl triazolyl-L-phenylalanine) (MPEO-b-PGTP) have been synthesized by the modification of poly(ethylene oxide)-b-poly (propargyl glycidyl ether) (MPEO-b-PGPE) with L-phenylalanine.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 338
Author(s):  
Martha Kafetzi ◽  
Stergios Pispas

In this work, the synthesis and the aqueous solution self-assembly behavior of novel partially hydrophobically modified poly(2-(dimethylamino) ethyl methacrylate)-b-poly(oligo(ethylelene glycol) methyl ether methacrylatetabel) pH and temperature responsive random diblock copolymers (P(DMAEMA-co-Q6/12DMAEMA)-b-POEGMA), are reported. The chemical modifications were accomplished via quaternization with 1-iodohexane (Q6) and 1-iodododecane (Q12) and confirmed by 1H-NMR spectroscopy. The successful synthesis of PDMAEMA-b-POEGMA precursor block copolymers was conducted by RAFT polymerization. The partial chemical modification of the diblocks resulted in the permanent attachment of long alkyl chains on the amine groups of the PDMAEMA block and the presence of tertiary and quaternary amines randomly distributed within the PDMAEMA block. Light scattering techniques confirmed that the increased hydrophobic character results in the formation of nanoaggregates of high mass and tunable pH and temperature response. The characteristics of the aggregates are also affected by the aqueous solution preparation protocol, the nature of the quaternizing agent and the quaternization degree. The incorporation of long alkyl chains allowed the encapsulation of indomethacin within the amphiphilic diblock copolymer aggregates. Nanostructures of increased size were detected due to the encapsulation of indomethacin into the interior of the hydrophobic domains. Drug release studies demonstrated that almost 50% of the encapsulated drug can be released on demand by aid of ultrasonication.


2008 ◽  
Vol 57 (4) ◽  
pp. 571-576 ◽  
Author(s):  
Dongshuang Li ◽  
Ke Sha ◽  
Yapeng Li ◽  
Peng Ai ◽  
Xiaotian Liu ◽  
...  

1999 ◽  
Vol 77 (8) ◽  
pp. 1311-1326 ◽  
Author(s):  
Neil S Cameron ◽  
Muriel K Corbierre ◽  
Adi Eisenberg

Asymmetric amphiphilic diblock copolymers self-assemble in selective solvents. Since 1995, when we first reported the systematic preparation of a sequence of various "crew-cut" aggregate morphologies from this class of copolymer in solution (1), we have identified a vast array of structures and have begun a detailed investigation of the thermodynamic and kinetic parameters that induce morphogenesis. Not only spheres, rods, bilayer and bicontinuous architectures, as well as inverted structures are observed, but also a selection of mixed, combined and much more complex aggregates is documented. All of these aggregates have a phase-separated insoluble core and a crew-cut soluble corona. Thus, all parameters that permit selective modification of the component of either phase or of the interface provide a window for morphological control. By carefully adjusting the polymer chain environment, it has been possible to develop a systematic understanding of morphogenic parameters, which include, among others, polymer composition, common solvent, initial concentration, temperature, type and concentration of added ions, method of preparation, and added homopolymer. To date, more than 30 publications have appeared in the literature from our group alone on this subject. One of the problems inherent with such a complicated system is the taxonomy or classification: which morphologies correspond to equilibrium positions and which are intermediate or trapped? An attempt at a logical presentation of the observed aggregates is given, preceded by a qualitative discussion of the thermodynamic framework for this system. Where possible, the transitions between morphologies are explained in the context of the thermodynamic parameters. Finally, parallels are drawn between the copolymer aggregates and biological architectures.Key words: crew-cut, morphology, block copolymer, self-assembly, amphiphile.


2021 ◽  
Vol 12 (37) ◽  
pp. 5377-5389
Author(s):  
Riccardo Wehr ◽  
Elena C. dos Santos ◽  
Moritz S. Muthwill ◽  
Vittoria Chimisso ◽  
Jens Gaitzsch ◽  
...  

Analysis of the membrane properties and stability of fully amorphous small and giant unilamellar vesicles composed of atactic or isotactic poly(butylene oxide)-block-poly(glycidol) (PBO-b-PG) amphiphilic diblock copolymers.


Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 827
Author(s):  
Xiaowei An ◽  
Weihong Lu ◽  
Jian Zhu ◽  
Xiangqiang Pan ◽  
Xiulin Zhu

Selenide-containing amphiphilic copolymers have shown significant potential for application in drug release systems. Herein, we present a methodology for the design of a reactive oxygen species-responsive amphiphilic diblock selenide-labeled copolymer. This copolymer with controlled molecular weight and narrow molecular weight distribution was prepared by sequential organoselenium-mediated reversible addition fragmentation chain transfer (Se-RAFT) polymerization and selenol-based nucleophilic reaction. Nuclear magnetic resonance (NMR) and matrix-assisted laser desorption/ionization time-to-flight (MALDI-TOF) techniques were used to characterize its structure. Its corresponding nanomicelles successfully formed through self-assembly from the copolymer itself. Such nanomicelles could rapidly disassemble under oxidative conditions due to the fragmentation of the Se–C bond. Therefore, this type of nanomicelle based on selenide-labeled amphiphilic copolymers potentially provides a new platform for drug delivery.


Sign in / Sign up

Export Citation Format

Share Document