pH-Controlled, Polymer-Mediated Assembly of Polymer Micelle Nanoparticles

Abstract

We describe pH-controlled, polymer-mediated assembly of polymer micelles in aqueous media based on reversible complexation between the micelles of pyrene-labeled poly(epsilon-caprolactone)-b-poly(carboxylic acid) copolymers and proton-accepting water-soluble polymers such as poly(ethylene glycol) (PEG), poly(2-ethyl-2-oxazoline) (PEtOz), and poly(1-vinylpyrrolidone) (PVP). The key factor determining assembly phenomena was identified as the modulation of hydrogen-bonding interaction between ionizable anionic micellar shells and the proton-accepting polymers by the pH control. As pH decreased from 7.4 to 2.0, the mixture of the polymer micelles and polymers underwent assembly and formed solid hybrids at specific pH values. The micelles assembled in the hybrid could be reversibly dispersed as micelles above specific pH ranges. The assembly/disassembly behavior as well as phase transitions of the micelle/proton-accepting polymer could be precisely controlled by adjusting pH. This assembling behavior depended on the rationally designed parameters such as the chemical structure and length of micellar shell-forming poly(carboxylic acid)s and the class of proton-accepting polymers.

Polyphosphazene nanoparticles for cytoplasmic release of doxorubicin with improved cytotoxicity against Dox-resistant tumor cells

“…In previous studies, Bae's group has developed pH-responsive polymeric micelles based on amphiphilic poly(L-histidine)-block-poly(ethylene glycol) copolymers and has extensively characterized in drug release behavior and anti-tumor activities [20][21][22]. Other pH-responsive polymers have also been proposed to be candidates for drug carriers for tumor treatment [23][24][25][26]. It is well known that drug efflux transporters act as permeability barriers for multidrug-resistant (MDR) cells, and P-glycoprotein (Pgp) is the most abundantly expressed drug efflux system in cell membranes, by actively extruding cytotoxic drugs against a concentration gradient from the cell [15][16][17].…”

Synthesis of a Novel Polymeric Material Folate-Poly(2-ethyl-2-oxazoline)-Distearoyl Phosphatidyl Ethanolamine Tri-Block Polymer for Dual Receptor and pH-Sensitive Targeting Liposome

“…In recent years, PEOz has been shown to be a pH-sensitive polymer with a favorable pK a value (4-6). 14,15) This pH sensitivity is very beneficial for achieving rapid release of anticancer drugs in acid conditions, such as in tumor tissue and the endosomelysosome system. The pH-sensitivity of PEOz had been confirmed in many studies utilizing PEOz as a block of the Regular Article * To whom correspondence should be addressed.…”

ATRP of Silylated Glycerol Monomethacrylate in Organic Medium for Convenient Synthesis of Amphiphilic Copolymers

“…Macroinitiator (4) was prepared according to methods described in the literature. [18] Two samples were used in this work, which had the following macromolecular characteristics: HO-PCL 45 -Br [M n ðGPCÞ ¼ 5 100 g Á mol À1 , M w =M n ¼ 1.35] and HO-PCL 150 -Br…”