Bioengineering Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan), Fax: (+81) 4-8462-4658; Current address: Department of Chemistry, Faculty of Science, Tokyo University of Science , 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan).
Chem Asian J. 2013 Dec;8(12):3079-84. doi: 10.1002/asia.201300704. Epub 2013 Sep 4.
Temperature-responsive diblock copolymers made of poly(N-isopropylacrylamide) (PNIPAAm) generated by reversible addition-fragmentation chain transfer (RAFT) polymerization and a single-stranded DNA (ssDNA) self-assembled into polymer micelles. The micelles consisted of the PNIPAAm core surrounded by the ssDNA corona with a hydrodynamic diameter up to 300 nm in an aqueous medium above the lower critical solution temperature. In a medium of high ionic strength, the formation of the fully matched duplex with the complementary ssDNA on the surface of the polymer micelles induced rapid and spontaneous aggregation. By contrast, the micelles remained dispersed under the identical conditions when single-base-substituted ssDNA was added to form the corresponding terminal-mismatched duplex on the micellar surface. This highly sequence-selective process took place irrespective of the size of the PNIPAAm core.
由可逆加成-断裂链转移（RAFT）聚合生成的聚 N-异丙基丙烯酰胺（PNIPAAm）和单链 DNA（ssDNA）组成的温敏两亲嵌段共聚物自组装成聚合物胶束。在高于下临界溶液温度的水相中，胶束由 PNIPAAm 核组成，ssDNA 冠围绕核，水动力直径可达 300nm。在高离子强度的介质中，与聚合物胶束表面互补 ssDNA 形成完全匹配的双链会诱导快速自发聚集。相比之下，当向胶束表面添加单碱基取代的 ssDNA 以形成相应的末端错配双链时，胶束在相同条件下仍保持分散状态。这种高度序列选择性的过程与 PNIPAAm 核的大小无关。
