CAREER: Bottlebrush polymers as gateways to multiresponsive structures

第一部分：非技术性概述活细胞控制什么进入它们，什么离开它们，使用仔细调节的跨膜蛋白组成的膜孔的运输，作为看门人。 在这样做的过程中，细胞能够评估环境中发生的事情并做出相应的反应。受此功能的启发，该CAREER项目的目标是开发独特的策略，使响应孔形成结构引入聚合物囊泡。具体来说，这项工作的目的是使用管状大分子，称为核壳瓶刷，以模拟跨膜蛋白的门控功能，并使一类新的材料，响应机械激活，光学刺激，酸度变化等，这些细胞状结构将有助于设计多响应系统，最终可能能够模仿感官，如触摸，视觉和嗅觉。基于这项研究奋进的结果，人们可以很容易地设想将类似的系统用于诸如靶向药物递送、传感以及用于高价值应用的主动过滤装置等应用。伴随着这些学术活动，社区活动将被用来促进STEM教育向公众，特别是代表性不足的少数民族。这些活动将包括超越艺术和科学的举措，鼓励初露头角的小学科学家成为创造者，并为研究生提供工具，成为未来的科学/技术全球思想家和领导者。本研究的根本目标是理解指导块状线性和瓶刷（BB）共组装的关键现象。两亲性共聚物的生物启发多响应聚合物囊泡的制造。为此，制定了一项综合和有针对性的战略，该战略依赖于三个相互关联的目标：（i）两亲性三嵌段共聚物的结构评价（例如刚度、叉指、侧链长度），（ii）理解两亲性线性和BB嵌段共聚物的共组装，和（iii）通过使用刺激如pH，光和机械力。可以在BB中控制的许多参数，通常是正交的，例如持续长度，嫁接长度和密度，使它们对这个项目特别有吸引力。这项工作的目的是带来迄今未被探索的方面的复杂的聚合物结构的自组装和他们的共组装与传统的线性嵌段共聚物。这项工作的更广泛的结果可以在模拟细胞过程的复杂的、区室化的聚合物囊泡的制造中实现，而且可以在依赖于按需货物释放的系统如活性过滤膜和/或靶向递送系统中实现。PI还将开展若干活动，以鼓励多样性，普遍促进STEM，并加强代表性不足的少数群体的参与。这些活动将包括创客大会和黑客马拉松，以及通过利用刺激响应材料固有的视觉吸引力来融合艺术和科学。促进全球科学观和将主动学习纳入课程是该职业项目的其他综合目标。该奖项反映了NSF的法定使命，并被认为是值得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的支持。

Part 1: Non-technical summaryLiving cells control what enters them and what leaves using carefully regulated transport across membrane pores made up of transmembrane proteins, which act as gatekeepers. In doing so, cells are able to assess what goes on in their environment and respond accordingly. Inspired by this function, the objective of this CAREER project is to develop unique strategies that enable the introduction of responsive pore-forming structures into polymeric vesicles. Specifically, the work aims to use tube-like macromolecules, known as core-shell bottlebrushes, to emulate the gating function of transmembrane proteins and enable a new class of materials that respond to mechanical activation, optical stimulation, changes in acidity, etc. These cell-like structures will help devise multiresponsive systems that may ultimately be capable of mimicking senses such as touch, sight, and smell. Building upon the results of this research endeavor, one can readily envision to use similar systems for applications such as targeted drug delivery, sensing, as well as active filtration devices for high-value applications. Concomitantly with these scholarly activities, community events will be used to promote STEM education to the general public and, particularly, underrepresented minorities. These activities will include initiatives that transcend the arts and sciences, encourage budding grade-school scientists to become makers, and provide graduate students with the tools to be scientific/technological global thinkers and leaders of tomorrow.Part 2: Technical summaryThe underlying goal of this research is to comprehend the crucial phenomena directing the co-assembly of blocky linear and bottlebrush (BB) amphiphilic copolymers towards the fabrication of bioinspired multiresponsive polymersomes. To this end, an integrative and directed strategy that relies on three connected aims was devised: (i) structural evaluation of amphiphilic triblock copolymers (e.g. stiffness, interdigitation, side-chain length), (ii) understanding of the co-assembly of amphiphilic linear and BB block copolymers, and (iii) bestowing of multi-stimuli-responsiveness to polymersomes by incorporating pore-forming BB triblocks in membranes using stimuli such as pH, light, and mechanical force. The numerous parameters that can be controlled in BBs, often orthogonally, such as persistence length, grafting length and density, make them especially alluring for this project. This work aims to bring about hitherto underexplored aspects of the self-assembly of complex polymeric architectures and their co-assembly with conventional linear block copolymers. The broader results of this work may be implemented in the fabrication of intricate, compartmentalized polymersomes that emulate cellular processes, but also in systems such active filtration membranes and/or targeted delivery systems that rely on on-demand cargo release. The PI will also implement several activities to encourage diversity and promote STEM universally and enhance participation of underrepresented minorities. These activities will include maker conferences and hackathons, as well as blending arts and sciences by exploiting the inherent visual appeal of stimuli-responsive materials. Promotions of global views of sciences and inclusion of active learning in curricula are amongst the other integrated objectives of this CAREER project..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.