Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

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.