Fluorescence to study aggregation of amphiphilic copolymers in aqueous media

1999 ◽  
Vol 141 (1) ◽  
pp. 293-301 ◽  
Author(s):  
Céline Frochot ◽  
Alain Brembilla ◽  
Pierre Lochon ◽  
Marie-Laure Viriot
Keyword(s):  
Aqueous Media ◽  
Amphiphilic Copolymers

scholarly journals Synthesis of amphiphilic copolymers based on acrylic acid, fluoroalkyl acrylates and n-butyl acrylate in organic, aqueous–organic, and aqueous media via RAFT polymerization

RSC Advances ◽  
2017 ◽  
Vol 7 (39) ◽  
pp. 24522-24536 ◽  
Author(s):  
N. S. Serkhacheva ◽  
O. I. Smirnov ◽  
A. V. Tolkachev ◽  
N. I. Prokopov ◽  
A. V. Plutalova ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Polyacrylic Acid ◽  
Self Assembly ◽  
Butyl Acrylate ◽  
Raft Polymerization ◽  
Aqueous Media ◽  
Amphiphilic Copolymers

Hydrophilic and amphiphilic polymeric trithiocarbonates based on polyacrylic acid are able to provide polymerization-induced self-assembly in copolymerization of butyl and fluoroalkyl acrylates.

scholarly journals Synthesis and Characterization of Macroinitiators Based on Polyorganophosphazenes for the Ring Opening Polymerization of N-Carboxyanhydrides

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1446
Author(s):  
Natalia Zashikhina ◽  
Marina Vasileva ◽  
Olga Perevedentseva ◽  
Irina Tarasenko ◽  
Tatiana Tennikova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Degradation Rate ◽  
Aqueous Media ◽  
Delivery Systems ◽  
In Vitro Cytotoxicity ◽  
Side Chains ◽  
Amphiphilic Copolymers ◽  
Hybrid Copolymers

Among the various biocompatible amphiphilic copolymers, biodegradable ones are the most promising for the preparation of drug delivery systems since they are destroyed under physiological conditions, that, as a rule, reduce toxicity and provide controlled release of the drug. Hybrid graft-copolymers consisting of the main inorganic polyphosphazene chain and polypeptide side chains are of considerable interest for the development of delivery systems with a controlled degradation rate, since the main and side chains will have different degradation mechanisms (chemical and enzymatic hydrolysis, respectively). Variable particle degradation rate, controlled by the adjusting the composition of substituents, will allow selective delivery in vivo and controlled drug release. The present work proposes the preparation of biodegradable macroinitiators based on polyorganophosphazenes for the synthesis of hybrid copolymers. Synthesis of novel biodegradable macroinitiators based on polyorganophosphazenes was performed via macromolecular substitution of a polydichlorophosphazene chain with the sodium alcoholates, amines and amino acids. The composition of copolymers obtained was calculated using NMR. These polyorganophosphazenes bearing primary amino groups can be considered as convenient macroinitiators for the polymerization of NCA of α-amino acids in order to prepare hybrid copolymers polyphosphazene-graft-polypeptide. The developed macroinitiators were amphiphilic and self-assembled in the aqueous media into nanoparticles. Furthermore, the ability to encapsulate and release a model substance was demonstrated. In addition, the in vitro cytotoxicity of synthesized polymers was evaluated using two cell lines.

scholarly journals Highly Efficient Modular Construction of Functional Drug Delivery Platform Based on Amphiphilic Biodegradable Polymers via Click Chemistry

2021 ◽  
Vol 22 (19) ◽  
pp. 10407
Author(s):  
Guangkuo Zhao ◽  
Tongtong Ge ◽  
Yunfeng Yan ◽  
Qi Shuai ◽  
Wei-Ke Su
Keyword(s):  
Drug Delivery ◽  
Click Chemistry ◽  
Aqueous Media ◽  
Cycloaddition Reaction ◽  
Kinetic Studies ◽  
Random Copolymers ◽  
Amphiphilic Copolymers ◽  
Modular Construction ◽  
Low Cytotoxicity

Amphiphilic copolymers with pendant functional groups in polyester segments are widely used in nanomedicine. These enriched functionalities are designed to form covalent conjugates with payloads or provide additional stabilization effects for encapsulated drugs. A general method is successfully developed for the efficient preparation of functional biodegradable PEG-polyester copolymers via click chemistry. Firstly, in the presence of mPEG as initiator, Sn(Oct)2-catalyzed ring-opening polymerization of the α-alkynyl functionalized lactone with D,L-lactide or ε-caprolactone afforded linear mPEG-polyesters bearing multiple pendant alkynyl groups. Kinetic studies indicated the formation of random copolymers. Through copper-catalyzed azide-alkyne cycloaddition reaction, various small azido molecules with different functionalities to polyester segments are efficiently grafted. The molecular weights, polydispersities and grafting efficiencies of azido molecules of these copolymers were investigated by NMR and GPC. Secondly, it is demonstrated that the resulting amphiphilic functional copolymers with low CMC values could self-assemble to form nanoparticles in aqueous media. In addition, the in vitro degradation study and cytotoxicity assays indicated the excellent biodegradability and low cytotoxicity of these copolymers. This work provides a general approach toward the preparation of functional PEG-polyester copolymers in a quite efficient way, which may further facilitate the application of functional PEG-polyesters as drug delivery materials.

scholarly journals Amphiphilic Copolymers Consisting of Vinylphenanthrene and Cationic Segments. Fluorescence Quenching by Amphiphilic Quenchers in Aqueous Media

1982 ◽  
Vol 14 (11) ◽  
pp. 861-868 ◽  
Author(s):  
Yotaro Morishima ◽  
Tohru Tanaka ◽  
Yoshihiro Itoh ◽  
Shun-ichi Nozakura
Keyword(s):  
Fluorescence Quenching ◽  
Aqueous Media ◽  
Amphiphilic Copolymers

scholarly journals Relationship between the Ionization Degree and the Inter-Polymeric Aggregation of the Poly(maleic acid-alt-octadecene) Salts Regarding Time

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1036
Author(s):  
Isabella Reyes ◽  
Maria M. Palacio ◽  
Cristhian J. Yarce ◽  
Jose Oñate-Garzón ◽  
Constain H. Salamanca
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Zeta Potential ◽  
Maleic Acid ◽  
Aqueous Media ◽  
Polymeric Materials ◽  
Polydispersity Index ◽  
Amphiphilic Copolymers ◽  
Ionization Degree ◽  
Macromolecular Systems

Alternating amphiphilic copolymers are macromolecular systems with a polarity duality in their structure, since they are generally formed by alternating segments corresponding to a potential electrolyte group and an alkyl (aliphatic or aromatic) group. These systems, depending on the ionization degree, as well as the time, may form different types of intra and interpolymeric aggregates in aqueous media. Therefore, this study, which in fact is the continuation of a previously reported work, is focused on establishing how the ionization degree of the sodium and potassium salts of the poly(maleic acid-alt-octadecene) affect zeta potential, pH, electrical conductivity, particle size, polydispersity index, and surface tension over time. The results showed that polymeric salts with a high ionization degree in aqueous media formed homogeneous systems with bimodal sizes and high zeta potential values, which tended to quickly become less negative, lowering the pH and slightly increasing the electrical conductivity; while systems with low ionization degree lead to the opposite, forming heterodispersed systems with several populations of particle sizes, high polydispersity, low zeta potential values, neutral and invariable pH values, and high electrical conductivity values. Consequently, these results suggest that the values of particle size, polydispersity index, zeta potential, pH, and electrical conductivity change regarding the polymeric ionization degree, as well as the time. Therefore, such variables should be considered and controlled when working with this kind of polymeric materials.

Self-assembly of pH-responsive and fluorescent comb-like amphiphilic copolymers in aqueous media

Polymer ◽  
2010 ◽  
Vol 51 (15) ◽  
pp. 3377-3386 ◽  
Author(s):  
Min Li ◽  
Guo Liang Li ◽  
Zhiguo Zhang ◽  
Jun Li ◽  
Koon-Gee Neoh ◽  
...  
Keyword(s):  
Self Assembly ◽  
Aqueous Media ◽  
Amphiphilic Copolymers ◽  
Ph Responsive
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