Thermo-responsive shell cross-linked PMMA-b-P(NIPAAm-co-NAS) micelles for drug delivery
Thermo-responsive shell cross-linked PMMA-b-P(NIPAAm-co-NAS) micelles for drug delivery
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DOI：
10.1016/j.ijpharm.2011.08.038
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发表时间：
2011-11-28
影响因子：
5.8
通讯作者：
Zhuo, Ren-Xi
中科院分区：
文献类型：
--
作者：
Chang, Cong;Wei, Hua;Zhuo, Ren-Xi
采用RAFT聚合法合成了温度响应型两亲性聚(甲基methacrylate)-b-poly(N-isopropylacrylamide-co-N-acryloxysuccinimide)-b-P(NIPAAM-co-NaS))嵌段共聚物。通过将嵌段共聚物直接溶解在水介质中，可以方便地制备出未交联的胶束，然后通过在胶束溶液中加入乙二胺作为双功能交联剂，进一步制备了壳层交联(SCL)胶束。光吸收测量表明，未交联型和交联型胶束的LCST分别为31.0℃和40.8℃。透射电子显微镜(TEM)表明，室温下，未交联态和交联态胶束在水相中均表现出良好的球形，而SCL胶束在40℃时仍能保持较小尺寸的球形，这是由于其具有交联型结构。体外药物释放研究表明，与未交联胶束相比，SCL胶束在高温下具有更慢、更持久的药物释放行为，这表明本文开发的SCL胶束作为新型智能载体在药物控制释放方面具有巨大的潜力。(C)2011爱思唯尔B.V.保留所有权利。
Thermo-responsive amphiphilic poly(methyl methacrylate)-b-poly(N-isopropylacrylamide-co-N-acryloxysuccinimide) (PMMA-b-P(NIPAAm-co-NAS)) block copolymer was synthesized by successive RAFT polymerizations. The uncross-linked micelles were facilely prepared by directly dissolving the block copolymer in an aqueous medium, and the shell cross-linked (SCL) micelles were further fabricated by the addition of ethylenediamine as a di-functional cross-linker into the micellar solution. Optical absorption measurements showed that the LCST of uncross-linked and cross-linked micelles was 31.0 degrees C and 40.8 degrees C, respectively. Transmission electron microscopy (TEM) showed that both uncross-linked and cross-linked micelles exhibited well-defined spherical shape in aqueous phase at room temperature, while the SCL micelles were able to retain the spherical shape with relatively smaller dimension even at 40 degrees C due to the cross-linked structure. In vitro drug release study demonstrated a slower and more sustained drug release behavior from the SCL micelles at high temperature as compared with the release profile of uncross-linked micelles, indicating the great potential of SCL micelles developed herein as novel smart carriers for controlled drug release. (c) 2011 Elsevier B.V. All rights reserved.