Lee Jiyoung, Park Jong Min, Jang Woo-Dong
Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, 03722 Seoul, Republic of Korea.
Carbohydr Polym. 2019 Oct 1;221:48-54. doi: 10.1016/j.carbpol.2019.05.068. Epub 2019 May 24.
As a dual-stimuli-responsive polymer, α-cyclodextrin-bearing telechelic poly(2-isopropyl-2-oxazoline) (CD-PiPrOx-CD) was prepared by living cationic ring opening polymerization followed by click reaction (copper-catalyzed alkyne-azide cycloaddition). The phase transition temperature (T) of CD-PiPrOx-CD (0.33 mM) in 10 mM PBS solution (150 mM NaCl, pH 7.4) was 42.9 °C, and dramatically changed to 8.5 °C upon addition of the azobenzene-bearing penta(ethylene glycol) (Az-5EG) (3.3 mM). A change in the T was again observed for the mixture solution of CD-PiPrOx-CD and Az-5EG upon ultra-violet (UV) irradiation at 365 nm. Under 365-nm UV irradiation for 30 min, the T of CD-PiPrOx-CD changed to 41.3 °C, indicating the release of Az-5EG from the host-guest complex. During alternate irradiation at 365 and 254 nm, the T changed in a fully reversible manner.
作为一种双刺激响应聚合物，通过活性阳离子开环聚合反应随后进行点击反应（铜催化的炔基-叠氮环加成反应）制备了带有α-环糊精的遥爪聚（2-异丙基-2-恶唑啉）（CD-PiPrOx-CD）。CD-PiPrOx-CD（0.33 mM）在10 mM PBS溶液（150 mM NaCl，pH 7.4）中的相变温度（T）为42.9°C，加入带有偶氮苯的五乙二醇（Az-5EG）（3.3 mM）后急剧变化至8.5°C。在365 nm紫外线（UV）照射下，CD-PiPrOx-CD与Az-5EG的混合溶液的T再次发生变化。在365 nm UV照射30分钟后，CD-PiPrOx-CD的T变为41.3°C，表明Az-5EG从主客体复合物中释放出来。在365和254 nm交替照射期间，T以完全可逆的方式变化。
