Abstract Introducing clickable groups onto polymer microspheres allows the microspheres to be facilely functionalized via a click reaction. In this report, we have synthesized monodisperse PMMA microspheres with clickable double bonds on the surface by one-step RAFT-assisted dispersion photopolymerization using a cyclohexyl-containing macro-RAFT agent as a stabilizer. This macro-RAFT agent, named P(THPAA-b-AA)-TTC, was synthesized by RAFT-mediated block copolymerization of a cyclohexyl-containing monomer (THPAA, obtained by esterification of cis-1,2,3,6-tetrahydrophthalic with 2-hydroxyethyl acrylate) and acrylic acid. The obtained microspheres were analyzed by 1H NMR and Iodometric method, indicating that the content of carbon double bonds on the microspheres increased with increasing the amount of P(THPAA-b-AA)-TTC in the polymerization feed. We then used a thiolated biotin to perform the photo-click reaction with the cyclohexene double bond on the microspheres, thereby attaching the biotin unit onto the microspheres. The biotinylated PMMA microspheres were found to be able to effectively immobilize fluorescein isothiocyanate streptavidin (FITC-SAv) via the specific adsorption of biotin to streptavidin, and thus exhibited clear fluorescence under confocal microscope. This study provides a convenient and feasible way to prepare surface-functionalized microspheres, which has great potential in biological applications as well as other fields.

中文翻译：

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单分散硫醇烯可点击聚合物微球的一步合成及其在生物功能化中的应用

摘要 在聚合物微球上引入可点击基团可以通过点击反应轻松地对微球进行功能化。在本报告中，我们使用含环己基的大分子 RAFT 试剂作为稳定剂，通过一步 RAFT 辅助分散光聚合合成了表面具有可点击双键的单分散 PMMA 微球。这种名为 P(THPAA-b-AA)-TTC 的大分子 RAFT 试剂是通过 RAFT 介导的含环己基单体（THPAA，通过顺式 1,2,3,6-四氢邻苯二甲酸酯化获得）的嵌段共聚反应合成的。与丙烯酸 2-羟乙酯）和丙烯酸。通过1H NMR和碘量法分析所得微球，表明微球上碳双键的含量随着聚合进料中P(THPAA-b-AA)-TTC量的增加而增加。然后我们使用硫醇化生物素与微球上的环己烯双键进行光点击反应，从而将生物素单元连接到微球上。发现生物素化的PMMA微球能够通过生物素对链霉亲和素的特异性吸附来有效固定异硫氰酸荧光素链霉亲和素（FITC-SAv），从而在共聚焦显微镜下表现出清晰的荧光。该研究为制备表面功能化微球提供了一种方便可行的方法，在生物应用和其他领域具有巨大的潜力。发现生物素化的PMMA微球能够通过生物素对链霉亲和素的特异性吸附来有效固定异硫氰酸荧光素链霉亲和素（FITC-SAv），从而在共聚焦显微镜下表现出清晰的荧光。该研究为制备表面功能化微球提供了一种方便可行的方法，在生物应用和其他领域具有巨大的潜力。发现生物素化的PMMA微球能够通过生物素对链霉亲和素的特异性吸附来有效固定异硫氰酸荧光素链霉亲和素（FITC-SAv），从而在共聚焦显微镜下表现出清晰的荧光。该研究为制备表面功能化微球提供了一种方便可行的方法，在生物应用和其他领域具有巨大的潜力。