文献类型：期刊文献

英文题名：A pH dependent thermo-sensitive copolymer drug carrier incorporating 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl (4-NH2-TEMPO) residues for electron spin resonance (ESR) labeling

作者：Yu, Ronghua[1]; Zhao, Hongli[1]; Zhao, Zijun[1]; Wan, Yuanyuan[1]; Yuan, Huihui[1,2]; Lan, Minbo[1,2,3]; Lindoy, Leonard F.[4]; Wei, Gang[5]

机构：[1] Shanghai Key Lab. of Functional Materials Chemistry and Research Centre of Analysis and Test, East China University of Science and Technology, Shanghai 200237, China; [2] Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237, China; [3] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; [4] School of Chemistry, The University of Sydney, NSW 2006, Australia; [5] CSIRO Materials Science and Engineering, PO Box 218, Lindfield, NSW 2070, Australia

年份：2011

卷号：362

期号：2

起止页码：584

外文期刊名：Journal of Colloid and Interface Science

收录：EI(收录号：20113214228444)

语种：英文

外文关键词：Paramagnetic resonance - Drug delivery - Electrons - Magnetic moments - Block copolymers - Electron spin resonance spectroscopy - Electrospinning - Lactic acid - Solutions - Fluorescence spectroscopy - Nuclear magnetic resonance - Spin dynamics

摘要：The fabrication of a new amphiphilic block copolymer composed of a poly dl-lactic acid (PLA) hydrophobic backbone and pH dependent thermo-sensitive poly (N-isopropyl) methacrylamide-co-N-isopropylmaleamic acid-co-10-undecenoic acid (PNIPAAm-co-NIPMMA-co-UA) entities as hydrophilic domains as well as carrying 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) residues for electron spin resonance (ESR) labeling is reported. The lower critical solution temperature (LCST) of the copolymer was determined by optical absorbance measurements. The LCST was pH dependent and varied in a narrow practical range, 35.4°C at pH 5.0, 37.5°C at pH 6.5 and 39.4°C at pH 7.4, which was below, near and above nominal physiological temperature respectively. The assembly of the copolymer into micelles in aqueous solution at temperatures below the LCST was confirmed by FT-IR, 1H NMR and fluorescence spectroscopy. It is demonstrated that the anticancer drug, 5-fluorouracil (5-FU) can be loaded effectively within the polymeric micelles and released in response to environmental stimuli- namely, pH and temperature. ? 2011.