Facile preparation of core-crosslinked micelles from azide-containing thermoresponsive double hydrophilic diblock copolymer via click chemistry
Facile preparation of core-crosslinked micelles from azide-containing thermoresponsive double hydrophilic diblock copolymer via click chemistry
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DOI：
10.1002/pola.22430
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发表时间：
2008-02-01
影响因子：
--
通讯作者：
Liu, Shiyong
中科院分区：
文献类型：
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作者：
Jiang, Xiaoze;Zhang, Jingyan;Liu, Shiyong
采用连续可逆加成-断裂链转移聚合的方法合成了双亲水双嵌段共聚物Poly(N，N-dimethylacrylamide)-b-poly(N-isopropylacrylamide-co-3-azidopropylacrylamide))-b-P(NIPAM-co-AzPAM)。得到的两嵌段共聚物在室温下以分子形式溶解在水溶液中，在P(NIPAM-co-AzPAM)嵌段的较低临界溶液温度以上，可以进一步超分子自组装成由热响应性P(NIPAM-co-AzPAM)核和水溶性PDMA冠冕组成的核-壳纳米粒子。由于胶束核中含有反应性叠氮残基，因此通过点击化学方法加入双官能团丙烯基醚即可实现核的交联化。在另一种方法中，将PDMA-b-P(NIPAM-co-AzPAM)两嵌段共聚物溶解在普通有机溶剂(DMF)中，可通过添加丙烯基醚并随后进行水透析来制备核-交联型(CCL)胶束。与前一种方法相比，后一种方法制备的CCL胶束通常具有更大的尺寸和更宽的尺寸分布。在这两种情况下，得到的(CCL)胶束都具有热响应核心，其膨胀/收缩可以随温度微调，使其成为智能药物纳米载体的极佳候选者。由于点击反应的效率高，条件温和，我们期待这一策略可以推广到其他自组装纳米结构的结构固定。(C)2007年威利期刊公司。
Double hydrophilic diblock copolymer, poly(N,N-dimethylacrylamide)-b-poly(N-isopropylacrylamide-co-3-azidopropylacrylamide) (]PDMA-b-P(NIPAM-co-AzPAM), containing azide moieties in one of the blocks was synthesized via consecutive reversible addition-fragmentation chain transfer polymerization. The obtained diblock copolymer molecularly dissolves in aqueous solution at room temperature, and can further supramolecularly self-assemble into core-shell nanoparticles consisting of thermoresponsive P(NIPAM-co-AzPAM) cores and water-soluble PDMA coronas above the lower critical solution temperature of P(NIPAM-co-AzPAM) block. As the micelle cores contain reactive azide residues, core crosslinking can be facilely achieved upon addition of difunctional propargyl ether via click chemistry. In an alternate approach in which the PDMA-b-P(NIPAM-co-AzPAM) diblock copolymer was dissolved in a common organic solvent (DMF), the core-crosslinked (CCL) micelles can be fabricated via "click" crosslinking upon addition of propargyl ether and subsequent dialysis against water. CCL micelles prepared by the latter approach typically possess larger sizes and broader size distributions, compared with that obtained by the former one. In both cases, the obtained (CCL) micelles possess thermoresponsive cores, and the swelling/shrinking of which can be finely tuned with temperature, rendering them as excellent candidates as intelligent drug nanocarriers. Because of the high efficiency and quite mild conditions of click reactions, we expect that this strategy can be generalized for the structural fixation of other self-assembled nanostructures. (C) 2007 Wiley Periodicals, Inc.