Key Laboratory of Functional Polymer Materials, Ministry of Education, Institute of Polymer Chemistry, Nankai University, Tianjin, PR China.
J Colloid Interface Sci. 2011 Apr 1;356(1):16-23. doi: 10.1016/j.jcis.2011.01.005. Epub 2011 Jan 7.
A straightforward approach to the synthesis of "clickable" thermoresponsive core cross-linked (CCL) nanoparticles was developed. This approach was based on reversible addition-fragmentation chain transfer (RAFT) radical cross-linking polymerization of styrene and divinylbenzene with azide-functionalized poly(N-isopropylacrylamide) (PNIPAM-N(3)) as macro chain transfer agent in a selective solvent. Spherical nanoparticles with a diameter of 12nm were obtained after 24h polymerization. When the lyophilized CCL nanoparticles were dispersed in THF, spherical nanoparticles were observed, confirming the stability of CCL nanoparticles. The transmission electron microscopy (TEM) studies demonstrated that spherical nanoparticles and wormlike structure coexisted in the aqueous solution. The CCL nanoparticles have a lower critical solution temperature (LCST) at about 29.6°C, a little lower than that of PNIPAM homopolymer. Biotin molecules were conjugated to the surface of CCL nanoparticles via "click" chemistry in aqueous media. After bioconjugation, the LCST shifted to 28.3°C. The bioavailability of biotin to protein avidin was evaluated by a 4'-hydroxyazobenzene-2-carboxylic acid/avidin (HABA/avidin) binding assay and TEM.
开发了一种直截了当的方法来合成“可点击”的温敏核交联（CCL）纳米粒子。该方法基于可逆加成-断裂链转移（RAFT）自由基交联聚合苯乙烯和二乙烯基苯，以叠氮功能化的聚（N-异丙基丙烯酰胺）（PNIPAM-N（3））作为大单体转移剂，在选择性溶剂中进行。聚合 24 小时后，得到直径为 12nm 的球形纳米粒子。当冻干的 CCL 纳米粒子分散在四氢呋喃中时，观察到球形纳米粒子，证实了 CCL 纳米粒子的稳定性。透射电子显微镜（TEM）研究表明，在水溶液中同时存在球形纳米粒子和蠕虫状结构。CCL 纳米粒子的临界溶液温度（LCST）约为 29.6°C，略低于 PNIPAM 均聚物。通过“点击”化学在水相介质中将生物素分子接枝到 CCL 纳米粒子表面。接枝后，LCST 移至 28.3°C。通过 4'-羟基偶氮苯-2-羧酸/亲和素（HABA/亲和素）结合测定和 TEM 评估了生物素对蛋白亲和素的生物利用度。
