Fabrication of thermosensitive PCL‐PNIPAAm‐PCL triblock copolymeric micelles for drug delivery |
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Authors: | Cong Chang Hua Wei Chang‐Yun Quan Yong‐Yong Li Jia Liu Zong‐Chun Wang Si‐Xue Cheng Xian‐Zheng Zhang Ren‐Xi Zhuo |
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Institution: | 1. Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, People's Republic of China;2. Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan 430072, People's Republic of China |
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Abstract: | A series of thermosensitive ABA type triblock poly(ε‐caprolactone)‐b‐poly(N‐isopropylacrylamide)‐b‐poly(ε‐caprolactone) (PCL‐PNIPAAm‐PCL) copolymers with different molecular weights were synthesized by the combination of ring opening polymerization and reversible addition‐fragmentation chain transfer (RAFT) polymerization. The critical micelle concentrations (CMCs) of the resulted four triblock copolymers in aqueous solution were determined to be 33.8, 39.8, 35.5, and 41.7 mg/L, respectively, by fluorescence spectroscopy using pyrene as a fluorescence probe. Optical absorption measurements showed that the lower critical solution temperatures (LCSTs) of the copolymers were 35.8, 36.2, 35.2, and 36.2 °C, respectively, in distilled water, and 33.9, 34.2, 33.3, 34.6 °C, respectively, in PBS (pH = 6.8, I = 0.1). Transmission electron microscopy (TEM) showed that the self‐assembled micelles exhibited a well‐defined spherical shape with diameter of around 100 nm. The drug‐loaded PCL‐PNIPAAm‐PCL micelles displayed thermosensitive controlled release behaviors. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3048–3057, 2008 |
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Keywords: | drug release micelle RAFT ring opening polymerization thermosensitive triblock copolymer |
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