Synthesis of double‐hydrophilic poly(methylacrylic acid)–poly(ethylene glycol)–poly(methylacrylic acid) triblock copolymers and their micelle formation

Abstract

The aim of the work reported was to synthesize a series of double‐hydrophilic poly(methacrylic acid)‐block‐poly(ethylene glycol)‐block‐poly(methacrylic acid) (PMAA‐b‐PEG‐b‐PMAA) triblock copolymers and to study their self‐assembly behavior. These copolymeric self‐assembly systems are expected to be potential candidates for applications as carriers of hydrophilic drugs. Bromo‐terminated difunctional PEG macroinitiators were used to synthesize well‐defined triblock copolymers of poly(tert‐butyl methacrylate)‐block‐poly(ethylene glycol)‐block‐poly(tert‐butyl methacrylate) via reversible‐deactivation radical polymerization. After the removal of the tert‐butyl group by hydrolysis, double‐hydrophilic PMAA‐b‐PEG‐b‐PMAA triblock copolymers were obtained. pH‐sensitive spherical micelles with a core–corona structure were fabricated by self‐assembly of the double‐hydrophilic PMAA‐b‐PEG‐b‐PMAA triblock copolymers at lower solution pH. Transmission electron microscopy and laser light scattering studies showed the micelles were of nanometric scale with narrow size distribution. Solution pH and micelle concentration strongly influenced the hydrodynamic radius of the spherical micelles (48–310 nm). A possible reason for the formation of the micelles is proposed. Copyright © 2010 Society of Chemical Industry

pH-responsive PMAA-b-PEG-b-PMAA triblock copolymer micelles for prednisone drug release and release kinetics

“…Meanwhile, the interpolymer complexes containing PMAA and PEG may occur over a wider pH range than those containing PAA and PEG [25], which is believed to be in favor of the formation of stable micelles. In comparison with the work by Tao and Liu [23,24], a remarkable merit of the current drug release system is the study of drug release kinetics and transport mechanism, especially in the simulated physiological medium of pH 7.4 and 37°C, which is much meaningful in obtaining physically meaningful parameters for comparative purposes and relating some release parameters such as bioavailability. Consequently, an effective target therapy against lesion tissues for these polymeric micelles may be accomplished by a combination of selective delivery to lesion sites based on stable micellar structures and pH-induced response.…”

“…Sun et al [22] reported synthesis and micellization of double-hydrophilic pH-responsive poly(acrylic acid)-b-poly(ethylene oxide)-b-poly (acrylic acid) (PAA-b-PEO-b-PAA) triblock copolymers. Tao and Liu [23,24] synthesized poly(methylacrylic acid)-poly(ethylene glycol)-poly(methylacrylic acid) (PMAAb-PEG-b-PMAA) triblock copolymers, and investigated their pH-sensitivity.…”