Biological systems can create materials with intricate structures and specialized functions. In comparison, precise control of structures in human-made materials has been challenging. Here we report on insect cuticle peptides that spontaneously form nanocapsules through a single-step solvent exchange process, where the concentration gradient resulting from the mixing of water and acetone drives the localization and self-assembly of the peptides into hollow nanocapsules. The underlying driving force is found to be the intrinsic affinity of the peptides for a particular solvent concentration, while the diffusion of water and acetone creates a gradient interface that triggers peptide localization and self-assembly. This gradient-mediated self-assembly offers a transformative pathway towards simple generation of drug delivery systems based on peptide nanocapsules.

生物系统可以创造具有复杂结构和特殊功能的材料。相比之下，对人造材料结构的精确控制一直具有挑战性。在这里，我们报道了昆虫角质层肽通过一步溶剂交换过程自发形成纳米胶囊，其中水和丙酮混合产生的浓度梯度驱动肽定位和自组装成中空纳米胶囊。研究发现，潜在的驱动力是肽对特定溶剂浓度的内在亲和力，而水和丙酮的扩散会产生梯度界面，从而触发肽定位和自组装。这种梯度介导的自组装为简单生成基于肽纳米胶囊的药物递送系统提供了一条变革途径。