pH-Sensitive Polymeric Micelles Based on PEG-Oligo(L-Lysine)-PCL System

Micelle;pH-sensitive;crosslinking;lysine;poly(ethylene glycol);poly(ε-caprolactone);620

공과대학 재료공학부 ;

University:서울대학교 대학원

关键词: Micelle;    pH-sensitive;    crosslinking;    lysine;    poly(ethylene glycol);    poly(ε-caprolactone);    620;   

Others  :  http://s-space.snu.ac.kr/bitstream/10371/123233/1/000000002956.pdf

美国|英语

来源: Seoul National University Open Repository

【 摘 要 】

Methoxy poly(ethylene glycol) amine with a molecular weight of 5K and ε-caprolactone with a molecular weight of 3K were conjugated to five lysine residues with a molecular weight and Mw/Mn of 9.6K and 1.04. The shift of peak molecular weight and narrow molecular weight distribution in GPC trace without any noticeable shoulder as well as 1H NMR analysis confirmed the successful synthesis of the copolymer. Polymeric micelles, size around 60 nm, were formed by dialysis and crosslinked micelles were prepared by adding crosslinker, terephthalaldehyde, to generate weak acid labile benzoic-imine bond in the interface of the micelle-forming amphiphilic copolymer. The critical micelle concentration of non-crosslinked micelle and crosslinked micelle was determined to be 4.26 x 10-2 mg/mL and 7.01 x 10-3 mg/mL, respectively. The hydrolysis rate of the crosslinked micelles is highly pH-dependent and much more rapid at mild acid than physiological conditions. Doxorubicin was successfully loaded into the crosslinked micelles and a controlled pH-dependent release behavior was observed. The enhanced micelle stability opens a way for preparing long circulating delivery systems encapsulating poorly water soluble drugs.