Chung Yueh-Chi, Yang Chien-Hsin, Lee Rong-Ho, Wang Tzong-Liu
Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan, Republic of China.
Department of Chemical Engineering, National Chung Hsing University, Taichung 402, Taiwan, Republic of China.
ACS Omega. 2019 Feb 14;4(2):3322-3328. doi: 10.1021/acsomega.8b03414. eCollection 2019 Feb 28.
An amphiphilic block copolymer (BCP) which contains both photoresponsive and thermoresponsive blocks was synthesized by the atom transfer radical polymerization approach. Meanwhile, a new core/shell type of the upconversion nanoparticle (UCNP) LiYF:Yb ,Tm @LiYF:Yb was successfully synthesized. By encapsulating UCNPs inside the micelles of the BCP and incorporating Nile red (NR) into the UCNP@BCP hybrid nanoparticles as a model drug, controlled release of the drug by the dual-stimuli BCP could be studied. After exposing the UCNP-loaded micellar solution to near-infrared (NIR) light, it was found that the UV light pumped from UCNPs could disrupt the polymer micelles and the fluorescence intensity of NR decreased with the increase of the irradiation time of the NIR light. The thermoresponsive study indicated that the fluorescence intensity of NR decreased with the increase of temperature of the micellar solution because of the release of NR into water arising from the contraction of the amphiphilic BCP.
通过原子转移自由基聚合方法合成了一种同时包含光响应性和热响应性嵌段的两亲性嵌段共聚物（BCP）。同时，成功合成了一种新型核壳型上转换纳米粒子（UCNP）LiYF:Yb,Tm@LiYF:Yb。通过将UCNPs包裹在BCP的胶束内部，并将尼罗红（NR）作为模型药物掺入UCNP@BCP杂化纳米粒子中，可以研究双刺激BCP对药物的控释情况。将负载UCNP的胶束溶液暴露于近红外（NIR）光下后，发现从UCNPs泵浦出的紫外光会破坏聚合物胶束，并且随着NIR光照射时间的增加，NR的荧光强度降低。热响应性研究表明，由于两亲性BCP收缩导致NR释放到水中，胶束溶液温度升高时NR的荧光强度降低。
