Dr. Gillies leads a research program in smart materials and biomaterials spanning from fundamental discoveries to applications with a focus on polymer chemistry and the design and synthesis of materials with new properties and functions. She is collaborating with other research groups to explore applications of her materials in drug delivery, regenerative medicine, and agriculture. This interview is brought to you by the BioTEC Break Coordinator Molly Lu.
BioTEC: Could you tell us more about your work at your lab? What exactly are new polymeric platforms for applications in drug delivery and tissue engineering?
Dr. Gillies: Drug delivery and tissue engineering are broad fields that encompass a lot of different expertise. I guess what we bring to it, is a chemistry perspective to solve some current challenges. For example, the conventional way to administer medicine is often through an oral pill or intravenous injection, and then the drug will then be distributed systemically and will reach the target site rather indirectly, which often brings many side effects. In terms of tissue engineering, you want to deliver cells locally and retain them there, which requires the right material to achieve that. While many people in the field are looking at naturally occurring polymers like polysaccharides, collagen, proteins from natural sources etc., what we are interested in doing is developing synthetic materials or hybrids between natural and synthetic materials. In doing so, we can incorporate an element of custom design into the system where we can achieve certain functions or mechanical properties.
BioTEC: What are some of the differences between natural and synthetic polymers?
Dr. Gillies: There are definitely some advantages to natural polymers. For example, you can mimic the natural environment around the cells. Also, often they are biodegradable. But with natural polymers, there is a limited possibility to do chemistry on them to tune their properties. Another challenge is the difficulty of isolation and purification. It is sometimes hard to remove bioactive components such as RNA, DNA, or proteins. In terms of reproducibility, different batches of the same natural material sometimes are inconsistent in their properties and lead to inconsistent results. On the other hand, for synthetic polymers, there is a chemical process and it can be well controlled and characterization is usually easier. However, sometimes we try to combine natural material and synthetic material to achieve the properties that we want. So there are different approaches and we can try to get the best of both aspects.
BioTEC: Regarding reproducibility, does that mean synthetic material tends to be more economically cost-effective than natural polymers?
Dr. Gillies: It really depends on the material. Often synthetic polymers can be quite cost-effective, whereas the challenge of isolating something from natural sources does raise the cost. For example, let’s say you want to generate cellulose from bacteria, there is the cost of culturing bacteria, separating by-products being produced, as well as steps of purification. An analogy could be thinking about traditional small molecule drugs versus biotherapeutics. For example, antibody therapeutics are actually quite expensive to produce. For small molecules drugs, they may be expensive for patent reasons, but often they can be synthesized quite economically due to simpler processes. Having said that, some natural materials can be quite inexpensive if they can be found in large quantities in nature, and in particular from waste resources.
BioTEC: How do you envision your research to be translated into an industry setting? For example, maybe a new medical product on the market?
Dr. Gillies: I would say that would be our long-term goal. As an academic researcher, we are often working a bit more on the discovery end to understand how the chemical structure and properties of polymers will influence biological behavior. However, I would like, ideally that our research is translated into some part of a product. As a couple of examples, we developed a polymer that can trigger depolarization under certain conditions. There is a startup company that is using this technique to make drug capsules. The capsules are designed to release the drugs at different locations in the digestive tract.
We are also trying to develop injectable materials to potentially deliver disease-modifying drugs for osteoarthritis. These are drugs that should not be administered orally because they might have side effects. By injecting them directly into the joint, there will be fewer side effects and the higher local concentrations should make them more effective for treatment.
In terms of the tissue engineering field, again, we are trying to develop a new scaffold
materials designed to incorporate bioactive elements with synthetic tunable material so we can control the cells that adhere to the scaffold and differentiate into the desired cell type.
BioTEC: Working as a researcher in the frontier of these fields, where do you see drug delivery and tissue engineering going in the future?
Dr. Gillies: Yes, I would say it is one of those frontier fields. Unlike cell phone applications, which might take a few months or a year to develop and bring to market, it does take a much longer time to develop materials to put into the human body.
It is really the future, I think, to develop less-toxic, more-effective therapeutics, and cell-based therapies.
I think the field is getting there, but perhaps it has been slower than what we would like it to be because it is complex and challenging to understand what happens when we put the material in the body. We need to be patient and do all the appropriate tests.
BioTEC: What initially motivated you to pursue a research career in the field of polymers and biomaterials? What did the journey look like?
Dr. Gillies: There definitely have been many turns. I actually entered the university as a psychology major. I became interested in learning about neurological drug design during a guest lecture in the first-year, which stimulated me to study chemistry. I was initially very interested in medicinal chemistry. I went to grad school expecting to join a medicinal chemistry group. However, in the U.S., you do rotations in different groups instead of just joining one immediately. It was back in 2000, I felt the medicinal chemistry was much developed, and later through a group meeting working on drug delivery, I found the field really interesting and very different.
BioTEC: What fascinated you the most about drug delivery? Is it because of the emergent opportunities associated with the unknown in the field?
Dr. Gillies: That is part of it. I think ultimately what I like to do, I see this repeated again and again in my career, as I like to see a problem and try to develop a solution. In education, you are trained to understand and develop tools to solve the problem. Ultimately what attracts me is I can always work on new projects and learn new things, and the concept of solving problems.
BioTEC: Could you elaborate on the newly emerging field of bio-based polymers?
Dr. Gillies: It is a hugely growing field. Just because something is synthetic, it doesn’t mean that it is not derived from natural sources. That is another element we work on as well. In ideal cases, the molecules that we use to build our polymers would be from nature. We would get the materials for example from agricultural waste sources so that we are not competing with food sources. For example, molecules like lignin or polysaccharides can serve as starting materials to prepare polymer building blocks, called monomers. These monomers can then be processed to produce polymers. It is not only important for biomedical applications but to replace conventional plastics. Right now a lot of the molecules we make polymers do  come from oil. The field is really moving from biosourced polymers.
BioTEC: Could you share some of the challenges you encountered during research
Dr. Gillies: One of the challenges, I speak for myself and most of my students, is that when you set out to something new, there is a high chance of failure. The idea may look nice on paper, and then simply not work out in the lab as planned. On the other hand, the rewarding part is when you finally solve your problems. Particularly for me, the most rewarding part is seeing personal growth in the students through the process. In the beginning, it is easy to feel discouraged when things don’t work, but if you stick with it and keep trying, success will follow.
In the end, we become more perseverant, resilient, and better problem-solvers. There are many who find the process difficult for this reason, but I think it is truly worth it.
Interested in Dr. Gillies’s research?