pH-Sensitivity Control of PEG-Poly(β-amino ester) Block Copolymer Micelle

• Published in: Macromolecular research Vol. 15; no. 5; pp. 437 - 442
• Main Authors: Hwang, Su Jong, Kim, Min Sang, Han, Jong Kwon, Lee, Doo Sung, Kim, Bong Sup, Choi, Eun Kyung, Park, Heon Joo, Kim, Jin Seok
• Format: Journal Article
• Language: English
• Published: 한국고분자학회 01.08.2007
• Subjects: 고분자공학; polymeric micelle; block copolymers; pH-sensitive; β-amino ester
• ISSN: 1598-5032; 2092-7673
• DOI: 10.1007/BF03218811

Poly(ethylene glycol) methyl ether (PEG)-poly(-amino ester) (PAE) block copolymers were synthesized using a Michael-type step polymerization, and the construction of pH-sensitive polymeric micelles (PM) investigated. The -amino ester block of the block copolymers functioned as a pH-sensitive moiety as well as a hydrophobic block in relation to the ionization of PAE, while PEG acted as a hydrophilic block, regardless of ionization. The synthesized polymers were characterized using 1H-NMR, with their molecular weights measured using gel permeation chromatography. The pKb values of the pH-sensitive polymers were measured using a titration method. The pH-sensitivity and critical micelle concentration (CMC) of the block copolymers in PBS solution were estimated using fluorescence spectroscopy. The pH dependent micellization behaviors with various bisacrylate esters varied within a narrow pH range. The critical micelle concentration at pH 7.4 decreased from 0.032 to 0.004mg/mL on increasing the number of methyl group in the bisacrylate from 4 to 10. Also, the particle size of the block copolymer micelles was determined using dynamic light scattering (DLS). The DLS results revealed the micelles had an average size below 100nm. These pH-sensitive polymeric micelles may be good carriers for the delivery of an anticancer drug. KCI Citation Count: 39