Pluronic polymeric micelles

Polymeric micelles formed by Pluronics, PEG phospholipid conjugates, PEG-b-polyesters, or PEG-b-poly-L-amino acids were proposed for drug delivery of poorly water-soluble compounds, such as amphotericin B, propofol, paclitaxel, and photosensitizers [77,86,87]. It was also emphasized that using polymeric micelles can significantly increase the drug transport into the brain. 

The use of polymeric micelles to deliver drugs to the central nervous system (CNS) has been reviewed recently. One strategy employs polymers with specific ligands to enhance transport across the blood-brain barrier (BBB), via interaction with receptor proteins on the BBB. Many of the polymers employed are derivatives of PEO- PPO PEO block copolymers (Pluronics). 

These are stable micelles that are formed with polymeric surfactants. Amphiphilic block copolymers such as the pluronics (polyoxyethylene-polyoxypropylene block copolymers) are able to self-assemble into polymeric micelles and hydrophobic drugs may be solubilized within the core of the micelle or, alternatively, conjugated to the micelle-forming polymer. Although micelles are rather dynamic systems that continuously exchange units between the micelle structure and the free units in solution, those composed of polyoxyethylene - poly(aspartic acid) have been found sufficiently... 

Simply modulating Pgp appears to be an extreme challenge in overcoming MDR in a clinical setting. As an alternative to Pgp modulators alone, various nanosized drug carriers have been tested to circumvent MDR in vitro and in vivo. Carriers include liposomes [216], alkylcyanoacrylate [217], nanoparticles [218], polymeric micelles of Pluronics [219] and other amphiphihc block copolymers [220], and PLGA nanoparticles [221]. 

Zhao, L., Shi, Y., Zou, S., Sun, M., Li, N., and Zhai, G. Eormulation and in vitro evalnation of qnercetin loaded polymeric micelles composed of pluronic P123 and D-a-tocopheryl polyethylene glycol succinates. Journal of Biomedical Nanotechnology 1 (2011) 358-365. 

Polymeric micelles to deliver photosensitizeis for photodynamic therapy van Nostmm CF Pluronics poly(ethylene glycol)-lipid conjugates pH-sensitive PiPAAm-based micelles polyion complex micelles dmg loading biodistribution studies therapeutic efficiency 2004 [65]... 

Amphiphilic block copolymers in selective solvents undergo self-assembly into various nanosized morphologies [2,3]. Typical aggregates formed by the block copolymers are polymeric micelles with spherical shapes consisting of a core and a coronal shell. These spherical polymeric micelles are several tens of nanometers across with a narrow size distribution, and they are characterized by their unique core-shell structure, in which a core composed of insoluble blocks is surrounded by a palisade of soluble (hydrophihc) blocks. So far, polymeric micelles intended for biomedical use have been prepared from a variety of amphiphilic block copolymers including PEO-fc-PBLA [51-56], poly(ethylene oxide)-fc-poly(propylene oxide)-fc-poly(ethylene oxide) (PEO-fo-PPO-fo-PEO) (Pluronic) [9], PEO-fo-phosphatidylethanolamine (PEO-fo-PE) [12,13], PEO-fo-PDLLA [40-43], PEO-fc-poly(e-caprolactone) (PEO-fc-PCL) [11], and PEO-fo-poly(lactide-co-glycolic acid) (PEO-fc-PLGA) [57]. 

Among the most commonly used thermosensitive polymers are poly(iV-isopropylacrylamide) (pNIPAAm) and pluronics (polyethylene glycol-b-polypropylene oxide-b-polyethylene glycol, PEG-h-PPO-h-PEG). The most extensively studied thermosensitive polymer is pNIPAAm with an LCST of 32°C. This has been used as a hydrophobic block of polymeric micelles with a PEG corona, as well as a hydrophilic shell combined with several other hydrophobic blocks. Work on the synthesis and applications of NIPAAm polymers as components for DDS (in most cases micelles) has been extensively described in several reviews over the years (Aoshima and Kanaoka, 2008 Schmaljohann, 2006 TaleUi and Hennink, 2011 Wei c/ /.,2009). 

Another study also utilized the technique of encapsulation of the chemotherapeutic agent within polymeric micelles in combination with a local ultrasonic irradiation of the tumor. Pure and mixed Pluronic P-105, PEG2000-diacylphospholipid, and... 

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