近日，美国加州大学圣芭芭拉分校Zvonimir Dogic团队研究了胶体组装和拆卸的拓扑结构和动力学途径。相关论文发表在2025年9月4日出版的《美国科学院院刊》杂志上。
封闭的胶囊，如脂质囊泡、肥皂泡和乳液滴，在生物学、工程物质和日常生活中无处不在。它们的产生和解体是由奇点定义的，奇点将拓扑上不同的扩展液膜从无边界的封闭壳中分离出来。这种拓扑变化过程具有根本性的意义。它们也是细胞间运输、细胞间通讯和药物传递所必需的。然而，囊泡形成的研究是具有挑战性的，因为涉及的快速动力学和小长度尺度。
研究组开发流体胶体，即微米大小的脂质囊泡类似物。胶体和脂质囊泡的机制用相同的理论模型来描述。研究组研究胶体接近其盘到球的拓扑转变。固有的胶体长度和时间尺度减缓了动态，以显示胶体在其组装和拆卸过程中的实时构象。值得注意的是，闭合囊泡转化为扁平圆盘的最低能量途径涉及一个拓扑结构不同的圆柱形中间体。这些结果揭示了与所有液体胶囊相关的拓扑变化方面。它们还为纳米级货物的封装、运输和交付提供了一个机器人平台。
附：英文原文
Title: Topology and kinetic pathways of colloidosome assembly and disassembly
Author: Adkins, Raymond, Robaszewski, Joanna, Shin, Seungwoo, Brauns, Fridtjof, Jia, Leroy, Khanra, Ayantika, Sharma, Prerna, Pelcovits, Robert A., Powers, Thomas R., Dogic, Zvonimir
Issue&Volume: 2025-9-4
Abstract: Closed capsules, such as lipid vesicles, soap bubbles, and emulsion droplets, are ubiquitous throughout biology, engineered matter, and everyday life. Their creation and disintegration are defined by a singularity that separates a topologically distinct extended liquid film from a boundary-free closed shell. Such topology-changing processes are of fundamental interest. They are also essential for intercellular transport, transcellular communication, and drug delivery. However, studies of vesicle formation are challenging because of the rapid dynamics and small length scale involved. We develop fluid colloidosomes, micrometer-sized analogues of lipid vesicles. The mechanics of colloidosomes and lipid vesicles are described by the same theoretical model. We study colloidosomes close to their disk-to-sphere topological transition. Intrinsic colloidal length and time scales slow down the dynamics to reveal colloidosome conformations in real time during their assembly and disassembly. Remarkably, the lowest-energy pathway by which a closed vesicle transforms into a flat disk involves a topologically distinct cylinder-like intermediate. These results reveal aspects of topological changes that are relevant to all liquid capsules. They also provide a robust platform for the encapsulation, transport, and delivery of nanosized cargoes.
DOI: 10.1073/pnas.2427024122
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2427024122