Emulsions are commonly used for drug delivery, yet they are usually limited to exclusively delivering either lipophilic or hydrophilic compounds. This separation negates possible synergetic therapeutic roles between such compounds. Here, we introduce a design for a short peptide that can stabilize emulsions. Upon binding certain metal ions, the peptide acts as a molecular switch, changes conformation, and becomes amphiphilic. Spectroscopic methods, NMR, and molecular dynamics provide information on the mechanism of this complexation-triggered amphiphilicity. The stability of these unique emulsions is based on histidine-metal bonds, which break at low pH values, selectively releasing their contents at the extracellular pH of tumors. Paclitaxel-encapsulated emulsion demonstrates strong activity against HeLa cells with an IC₅₀ of 70 nM, possibly enhanced by the simultaneous release of Zn²⁺ ions. Importantly, the emulsion is easily functionalized with various hexahistidine-tagged motifs that can supply the emulsion with many functions beyond drug delivery.

乳液通常用于药物递送，但它们通常仅限于专门递送亲脂性或亲水性化合物。这种分离否定了这些化合物之间可能的协同治疗作用。在这里，我们介绍了一种可以稳定乳液的短肽的设计。结合某些金属离子后，肽充当分子开关，改变构象，并变成两亲性的。光谱方法、核磁共振和分子动力学提供了有关这种络合引发的两亲性机制的信息。这些独特乳液的稳定性基于组氨酸-金属键，组氨酸-金属键在低 pH 值下断裂，在肿瘤细胞外 pH 值下选择性释放其内容物。紫杉醇封装乳液对 HeLa 细胞表现出很强的活性，IC ₅₀为 70 nM，可能通过同时释放 Zn ²⁺离子而增强。重要的是，该乳液很容易用各种六组氨酸标记的基序进行功能化，这些基序可以为乳液提供除药物输送之外的许多功能。