Triply responsive coumarin-based microgels with remarkably large photo-switchable swelling
Triply responsive coumarin-based microgels with remarkably large photo-switchable swelling
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DOI：
10.1039/c9py00233b
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发表时间：
2019-05-28
影响因子：
4.6
通讯作者：
Saunders, Brian R.
中科院分区：
文献类型：
--
作者：
Lu, Dongdong;Zhu, Mingning;Saunders, Brian R.
具有可以使用光可逆地改变的溶胀尺寸的可溶胀交联聚合物胶体颗粒（微凝胶）是罕见的。我们报道了四种不同的三重响应微凝胶的合成，所制成的直径范围从25到124 nm。每个MG系统都具有pH、温度和光响应性。这些聚（MEO 2 MA-co-MAA-co-CMA）微凝胶是使用甲基丙烯酸2-（2-甲氧基乙氧基）乙酯（MEO 2 MA）、甲基丙烯酸（MAA）和7-（2-甲基丙烯酰氧基乙氧基）-4-甲基香豆素（CMA）的沉淀共聚制备的。这种一步合成方法是可扩展的。该微凝胶体系具有强烈的pH和温度响应性。它们还可以使用UV照射在高度交联和去交联状态之间进行光切换。通过在365 nm（光交联状态）和254 nm（光去交联状态）的波长下照射，可以容易地控制有效交联剂密度。有趣的是，发现光解交联后的颗粒体积比增加是其他基于纳米颗粒的系统所报道的至少两倍。本发明的微凝胶的强的光开关行为被示出是由于CMA在颗粒内的均匀掺入。出乎意料的是，发现光诱导二聚化的程度随着所制备的微凝胶尺寸的减小而增加。该微凝胶的光致溶胀用于加速抗癌药物阿霉素的释放，以展示未来按需药物释放应用的潜力。
Swellable crosslinked polymer colloid particles (microgels) which have a swollen size that can be reversibly changed using light are rare. We report the synthesis of four different triply responsive microgels with as-made diameters ranging from 25 to 124 nm. Each MG system is pH-, temperature-and photo-responsive. These poly(MEO2MA-co-MAA-co-CMA) microgels were prepared using precipitation copolymerisation of 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA), methacrylic acid (MAA) and 7-(2-methacryloyloxyethoxy)- 4-methylcoumarin (CMA). This one-step synthesis method is scalable. The microgel systems were strongly pH-and temperature-responsive. They were also photo-switchable between highly crosslinked and de-crosslinked states using UV-irradiation. The effective crosslinker density was easily controlled by irradiation at wavelengths of 365 nm (photo-crosslinked state) and 254 nm (photo-de-crosslinked state). Interestingly, the particle volume ratio increase upon photo-de-crosslinking was found to be at least twice that reported for other nanoparticle-based systems. The strong photo-switching behaviour of the present microgels was shown to be due to a uniform incorporation of CMA within the particles. Unexpectedly, it was found that the extent of photo-induced dimerisation increased with a decrease in the as-made microgel size. The photo-induced swelling of the microgel was used to accelerate the release of the anti-cancer drug doxorubicin to demonstrate potential for future application for ondemand drug release.