Organized responsive soft matter: films and colloids

纳米技术影响着我们的日常活动，包括医疗保健。诊断工具以及医学成像或药物配方依赖于聚合物纳米颗粒，以保护其负载免受恶劣的体内环境的影响。我们最近发现聚甜菜碱可以绕过胞吞作用使细胞膜移位，从而导致高药物摄取。这一成功鼓励我们加深对聚甜菜碱与细胞膜相互作用的基本理解，使用模型磷脂囊泡和界面。具体来说，我们将评估聚甜菜碱链的拓扑结构（线性、环状、星形）对其被细胞膜吸收的影响。模拟和一些实验表明链拓扑在药物传递中的重要性，但这个主题大多未被探索。制备拓扑纯聚合物是困难的。凭借我们之前成功合成环状和星型非离子聚合物的经验，我们已经做好了克服这一挑战的准备。***该项目的第二部分致力于创造光驱动微型马达，作为未来诊断或治疗工具的模型。微型马达是由化学燃料或光自发驱动的。它们作为个体的运动只受环境的影响。在群体中，它们的动作是协调的。它模仿了活跃物质的集体运动特征，比如鸟群中的集体飞行。我们将制备带有光敏基团的聚合物微球，这些光敏基团通过与悬浮流体的界面张力变化来响应光，这是微球运动的原因。我们将监控他们个人和群体的行动。我们的观察将有助于理解活性物质的物理学。更重要的是，在未来，我们设想监测和控制它们与活细胞混合时的运动，用于体外受精和细胞间相互作用等应用。这个项目的设计反映了对重要和困难问题的答案的追求，以及培养下一代科学家的愿望。该计划利用高分子科学的各个方面：合成、表征、物理化学和自组装，为培养对加拿大未来重要领域的年轻科学家提供了丰富多样的领域，因为加拿大对高技能人才的需求很大。

Nanotechnology affects our daily activities, including medical care. Diagnostics tools as well as medical imaging or drug formulations rely on polymer nanoparticles that protect their load against the harsh in-vivo environment. We recently discovered that poly(betaines) can translocate the cell membrane, bypassing endocytosis, which results in high drug uptake. This success encouraged us to deepen our fundamental understanding of the interactions of poly(betaines) with the cell membrane, using model phospholipids vesicles and interfaces. Specifically, we will assess the effects of the topology (linear, cyclic, star-like) of the poly(betaine) chains on their uptake by the cell membrane. Simulations and a few experiments indicate the importance of chain topology in drug delivery, but the topic is mostly unexplored. The preparation of topologically pure polymers is difficult. With our previous experience in the successful synthesis of cyclic and star nonionic polymers, we are well prepared to overcome the challenge. ***The second part on the project is devoted to the creation of light-driven micro motors, as models for futuristic diagnostic or therapeutic tools. Micro motors move spontaneously powered by chemical fuel or light. Their motion as individuals is affected only by their environment. In groups, their motion is coordinated. It mimics the collective motion characteristic of what is known as active matter, such as the collective flight of birds in a flock. We will prepare polymeric microspheres bearing photosensitive groups that respond to light by a change of their interfacial tension with the suspending fluid, which is responsible for the microsphere motion. We will monitor their motion as individual and as groups. Our observations will contribute to the understanding of the physics of active matter. More importantly, in the future we envisage to monitor and control their motion when mixed with live cells for applications such as in-vitro fertilization and intercellular interactions. ***The design of this project reflects a quest for answers to important and difficult questions as well as a desire to train the next generation scientists. The program exploits all aspects of polymer science: synthesis, characterization, physical chemistry, and self-assembly, providing a rich and varied area for the training of young scientist in fields of importance to the future of Canada, where highly skilled manpower is in great demand.