Janus Liposomes in Motion

在奥本大学化学系大分子、超分子和纳米化学项目的支持下，詹伟和他的研究小组将开发一种基于Janus脂质体的新型生物相容性微电机。Janus脂质体是脂质双分子层的球形小颗粒，在水中自组装形成。Janus脂质体由结构不同的两半组成，因此得名Janus，双面罗马的变化和二元之神。如果成功，这项研究将生产出能够在低电场、光或生物制剂（如胆固醇和酶）下进行定向运动的小型物体。这些对刺激有反应的移动粒子可能会在几个领域发挥作用，例如，作为生物传感器或目标货物运输。这项研究的结果将在文献中广泛传播，也将通过基于互联网的教育平台传播给公众。此外，詹氏小组计划开展外展活动，例如为小学生和他们的父母提供与科学相关的实践体验。奥本大学的詹小组率先开发了不对称Janus脂质体，作为一类新的基于脂质的组装纳米结构。在这项正在进行的研究中，Janus脂质体将被设计成含有反应性构建块，利用其破碎的表面对称性和化学非均质性，允许定向运动对抗布朗运动和水中的粘性阻力。三种基本驱动力或通道将被用来推动这些自组装粒子：(i)电场，（ii）光和（iii）酶促反应（降低激活势垒）。总之，这些努力将极大地促进对Janus脂质体主动/定向运动的机制，能力和应用的理解-这是一个在其他快速发展的领域中尚未开发的一类材料。这样一个系统的方法也可能产生洞察力，以建立多响应，功能可编程的微型电机。这项研究的目标是脂质结构，它长期以来一直是生物细胞的原型，有可能为自然马达的功能和集体行为提供新的线索。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Wei Zhan and his research group at Auburn University will develop a new type of biocompatible, micromotor based on Janus liposomes. Janus liposomes are small spherical particles of lipid bilayer formed by self-assembly in water. Janus liposomes are comprised of two halves with different structures – hence their name after, Janus, the two-faced Roman god of change and duality. If successful, this research will yield small-sized objects that can perform directional motion in response to low electric fields, light, or biological agents such as cholesterol and enzymes. These stimulus-responsive moving particles potentially will be useful in several areas, for example, as biosensors or for targeted cargo delivery. Results of this research will be broadly disseminated in the literature, but also through internet-based educational platforms that reach the general public. In addition, the Zhan group plans to conduct outreach activities such as providing for hands-on science-related experiences for elementary school students and their parents.The Zhan group at Auburn University has pioneered the development of asymmetric Janus liposomes as a new class of lipid-based assembled nanostructure. In this ongoing research, Janus liposomes will be designed to contain reactive building blocks that would allow for directional movement against Brownian motion and viscous drag in water, taking advantage of their broken surface symmetry and chemical heterogeneity. Three fundamental driving forces or gateways will be employed to propel these self-assembled particles: (i) electric fields,(ii) light and (iii) enzymatic reactions (lowers activation barrier). Together, these efforts will substantially advance understanding on the mechanisms, capabilities and applications of active/directional motion of Janus liposomes – an underexplored class of materials in an otherwise rapidly growing field. Such a systematic approach will also likely yield insight into building multi-responsive, function-programmable micromotors. This research is targeting a lipid architecture that has long served as a prototype of biological cells and has the potential to shed new light on the function and collective behavior of natural motors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.