Amphiphilic poly micelles

Arimura H, Ohya Y, Ouchi T (2005) Formation of core-shell type biodegradable polymeric micelles from amphiphilic poly(aspartic acid)-Wock-polylactide diblock copolymer. Biomacromolecules 6 720-725... 

Gohy JE, Lohmeijer BGG, Alexeev A, Wang XS, Manners 1, Winnik MA, Schubert US (2004) Cylindrical micelles from the aqueous self-assembly of an amphiphilic poly(ethylene oxide)-b-poly(ferrocenylsilane) (PEO-b-PES) block copolymer with a metallo-supramolecular linker at the block junction. Chem Eur J 20 4315 323... 

Amphiphilic poly(ethylene glycol)-alkyl dextran ethers are emerging as vehicles in the oral delivery of poorly water soluble drugs [251,268,269]. They form polymer micelles of low critical association concentrations (CAC) and small micelle sizes in aqueous solution. Particulate delivery systems lead to an enhancement of the absorption efficiency and bioavailability of highly hpophihc drugs orally applied, and provide the drug with some level of pro-... 

Erhardt R et al (2003) Amphiphilic Janus micelles with polystyrene and poly(methacrylic acid) hemispheres. J Am Chem Soc 125(11) 3260-3267... 

Three-layered nanoparticles containing an hbPG core and cross-linked block copolymers based on N-isopropyl acrylate and N,N-dimethylaminoethyl acrylate as the respective arms were synthesized and proved to be thermoresponsive. ° Chu and co-workers" reported electrically conductive core-shell nanoparticles based on poly(n-butylacrylate-b-polystyrene) multiarm star polymers. The PS segments were converted to poly(p-styrenesulfonate) (PSS), thus generating amphiphilic tmimolecular micelles. Then the oxidative propagation of 3,4-ethylenedioxythiophene (EDOT) on the PSS chains was carried out by counterion-induced polymerization to produce a stable aqueous dispersion of the respective PEDOT complex. 

Gheybi, H. and Entezami, AA. (2013) Nanosized micelles self-assembled from amphiphilic poly(citric acid)—poly(e-caprolactone)—poly(citric acid) copolymers. Polym. Bull, 70, 1875. 

Section 3 then reviews the behavior of diblock copolymers in mixed micelles with surfactants. Section 4 discusses other polymer surfactant mixtures, such as mixtures of amphiphilic poly(para-phenylenes) (PPP) with nonionic surfactants [48]. The packing parameter and the curvature of an amphiphilic BCP are not only influenced by means of co-micellization with a surfactant. Both parameters can also be influenced by changing the solvent quality for one of the blocks, e.g., by adding alcohol or salt. Denkova et al. have shown that this also leads to structural changes [49], However, despite the similarity of both approaches, the present review will only focus on aqueous BCP surfactant mixtures. Surfactants can also be used to assist structure formation in BCP thin films [50], This is an area of growing importance, but is beyond the scope of the present contribution. 

Y. Yu, X. Zhang, and L. Qiu, The anti-tumor efficacy of curcumin when delivered by size/ charge-changing multistage polymeric micelles based on amphiphilic poly(beta-amino ester) derivates. Biomaterials, 35 (10), 3467-79,2014. 

Cao T, Munk P, Ramireddy C, Tuzar Z, Webber SE (1991) Fluorescence studies of amphiphilic poly(methacrylic acid)-i)/ock-polystyrene-b/ock-poly(methacrylic acid) micelles. Macromolecules 24 6300-6305... 

Blau and co-workers prepared a CNT-polymer hybrid by suspended SWNTs in organic solvents poly (p-phenylenevinylene-co-2,5-dioctyloxy-m-phenylenevinylene) to wrap the copolymer around the CNTs. The electrical properties of these hybrids were improved relative to those of the individual components. A noncovalent method has been used to functionalize SWNTs by encapsulating SWNTs within cross-linked and amphiphilic poly(styrene)-blocfe-poly(actylic add) copolymer micelles (Figure 19). This encapsulation significantly enhanced the dispersion of SWNTs in a wide variety of polar and nonpolar solvents and polymer matrices because the copolymer shell was permanently fixed. Thus, encapsulated SWNTs may be stabilized with respect to typical polymer processing and recovery from the polymer matrix. 

This chapter deals with a recently developed unimer micelle, a novel intramolecular assembly with a higher-order structure, formed from tailored amphiphilic random copolymers bearing charge and bulky hydrophobes. The first half of this chapter will be devoted to the synthesis of such amphiphilic poly electrolytes and characterization of the unimer micelle. The functionalization of the unimer micelles with chromophoric molecules and some functional properties of these functionalized unimer micelles will be described in some detail in the second half of this chapter. 

M. Zulauf, K. Weckstrom, J. B. Hayter, V. Degiorgio, M. Corti. Neutron scattering study of micelle structure in isotopic aqueous solutions of poly(oxy-ethylene) amphiphiles. J Phys Chem 29 3411-3417, 1985. 

The pioneering work on amphiphilic polyelectrolytes goes back to 1951, when Strauss et al. [25] first synthesized amphiphilic polycations by quaternization of poly(2-vinylpyridine) with n-dodecyl bromide. They revealed that the long alkyl side chains attached to partially quaternized poly(vinylpyridine)s tended to aggregate in aqueous solution so that the polymers assumed a compact conformation when the mole fraction of the hydrophobic side chains exceeded a certain critical value. Thus, Strauss et al. became the first to show experimentally the intramolecular micellation of amphiphilic polymers and the existence of a critical content of hydrophobic residues which may be compared to the critical micelle concentration of ordinary surfactants. They called such amphiphilic polyelectrolytes polysoaps [25],... 

As has been described in Chapter 4, random copolymers of styrene (St) and 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS) form a micelle-like microphase structure in aqueous solution [29]. The intramolecular hydrophobic aggregation of the St residues occurs when the St content in the copolymer is higher than ca. 50 mol%. When a small mole fraction of the phenanthrene (Phen) residues is covalently incorporated into such an amphiphilic polyelectrolyte, the Phen residues are hydrophobically encapsulated in the aggregate of the St residues. This kind of polymer system (poly(A/St/Phen), 29) can be prepared by free radical ter-polymerization of AMPS, St, and a small mole fraction of 9-vinylphenanthrene [119]. 

The use of ordered supramolecular assemblies, such as micelles, monolayers, vesicles, inverted micelles, and lyotropic liquid crystalline systems, allows for the controlled nucleation of inorganic materials on molecular templates with well-defined structure and surface chemistry. Poly(propyleneimine) dendrimers modified with long aliphatic chains are a new class of amphiphiles which display a variety of aggregation states due to their conformational flexibility [38]. In the presence of octadecylamine, poly(propyleneimine) dendrimers modified with long alkyl chains self-assemble to form remarkably rigid and well-defined aggregates. When the aggregate dispersion was injected into a supersaturated... 

Many kinds of nonbiodegradable vinyl-type hydrophilic polymers were also used in combination with aliphatic polyesters to prepare amphiphilic block copolymers. Two typical examples of the vinyl-polymers used are poly(/V-isopropylacrylamide) (PNIPAAm) [149-152] and poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) [153]. PNIPAAm is well known as a temperature-responsive polymer and has been used in biomedicine to provide smart materials. Temperature-responsive nanoparticles or polymer micelles could be prepared using PNIPAAm-6-PLA block copolymers [149-152]. PMPC is also a well-known biocompatible polymer that suppresses protein adsorption and platelet adhesion, and has been used as the hydrophilic outer shell of polymer micelles consisting of a block copolymer of PMPC -co-PLA [153]. Many other vinyl-type polymers used for PLA-based amphiphilic block copolymers were also introduced in a recent review [16]. 

Polymer micelles are nanometer sized (usually several tens of nanometers) self-assembled particles having a hydrophobic core and hydrophilic outer shell composed of amphiphilic AB- or ABA-type block copolymers, and are utilized as drug delivery vehicles. The first polymer micelle-type drug delivery vehicle was made of PEG-b-poly(aspartic acid) (PEG-b-PAsp), immobilizing the hydro-phobic anticancer drugDXR [188-191]. After this achievement by Kataoka et al., a great amount of research on polymer micelles has been carried out, and there are several reviews available on the subject [192-194]. 

Here, we focus on one class ofblock copolymers synthesized by this method polystyrene-6-poly(vinylperfluorooctanic acid ester) block copolymers (Figure 10.33). After describing the synthesis and characterization, we will treat some properties and the potential applications of this new class ofblock copolymers. The amphiphilicity of the polymers is visualized by the ability to form micelles in diverse solvents that are characterized by dynamic light scattering (DLS). Then the use of these macromolecules for dispersion polymerization in very unpolar media is demonstrated by the polymerization of styrene in 1,1,2-trichlorotrifluoroethane (Freon 113). 

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