Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, 10617, Taiwan (R.O.C.
Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan (R.O.C.
Chemistry. 2023 Jul 14;29(40):e202300884. doi: 10.1002/chem.202300884. Epub 2023 Jun 5.
Multiple triggered-release strategies are widely utilized to control the release of caged target molecules. Among them, photocages with conditional triggers provide extra layers of control in photorelease. In this work, a series of pH-responsive photocages was designed that could be triggered under irradiation and specific intracellular pH values. pH-sensitive phenolic groups were conjugated with o-nitrobenzyl (oNB) to form azo-phenolic NPX photocages with tunable pKa. These azo-phenol-based oNB photocages showed differentiable photoreleasing profiles at pH 5.0, 7.2 and 9.0. By attaching fluorogenic cargos, it was shown that one of the photocages, NPdiCl, could be used to differentiate between acidic pH 5.0 and neutral pH 7.2 in cells under artificial pH conditions. Finally, NPdiCl was identified as a promising pH-responsive photocage for photoreleasing cargo inside acidic tumor cells.
多种触发式释放策略被广泛应用于控制被笼蔽靶分子的释放。其中，具有条件触发的光笼为光释放提供了额外的控制层次。在这项工作中，设计了一系列 pH 响应型光笼，可在光照和特定的细胞内 pH 值下被触发。将 pH 敏感的酚基团与邻硝基苄基（oNB）偶联，形成具有可调 pKa 的偶氮酚 NPX 光笼。这些基于偶氮酚的 oNB 光笼在 pH 5.0、7.2 和 9.0 下显示出可区分的光释放特性。通过连接荧光标记的负载物，表明其中一种光笼 NPdiCl 可在人工 pH 条件下区分细胞内酸性 pH 5.0 和中性 pH 7.2。最后，NPdiCl 被鉴定为一种有前途的 pH 响应型光笼，可用于在酸性肿瘤细胞内光释放货物。
