Cytosolic delivery of peptides remains a challenging task because of the limited binding sites on peptides and the existence of multiple intracellular barriers. Here, we proposed the use of polycatechols with a high cell permeability to deliver peptides of different physicochemical properties using the catechol-boronate chemistry. Peptides were decorated with boronate moieties via three strategies, and the introduced boronate groups greatly increased the binding affinity of cargo peptides with polycatechols. The loading peptides could be released under the endolysosomal acidity. When the cargo peptide was modified with boronate moiety via a p-hydroxybenzylcarbamate self-immolative spacer, it could be loaded by polycatechols and released in a traceless manner triggered by reactive oxygen species. The proposed strategies greatly promote the cytosolic delivery efficiency of different peptides into various cell lines and restored their biofunctions after intracellular delivery and release. This study provides a general and robust platform for the intracellular delivery of membrane-impermeable peptides.

中文翻译：

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通过儿茶酚-硼酸盐化学在细胞溶质肽递送中具有稳健效率的聚儿茶酚

由于肽上有限的结合位点和多个细胞内屏障的存在，肽的细胞溶质递送仍然是一项具有挑战性的任务。在这里，我们建议使用具有高细胞渗透性的聚儿茶酚，使用儿茶酚-硼酸盐化学传递具有不同物理化学性质的肽。通过三种策略用硼酸酯部分修饰肽，并且引入的硼酸酯基团大大增加了货物肽与聚儿茶酚的结合亲和力。加载肽可以在内溶酶体酸度下释放。当货物肽通过p用硼酸盐部分修饰时-羟基苄基氨基甲酸酯自牺牲间隔物，它可以被多邻苯二酚负载并由活性氧物质触发以无痕方式释放。所提出的策略极大地促进了不同肽向各种细胞系中的胞质递送效率，并在细胞内递送和释放后恢复了它们的生物功能。该研究为膜不透性肽的细胞内递送提供了一个通用且强大的平台。