How micro-robots could change the way scientists manipulate biological cells

U of T researchers have engineered non-invasive tiny robots that can manipulate cells

How micro-robots could change the way scientists manipulate biological cells

Tiny robots that can control light could prove to be a non-invasive method for micro-manipulating cells, according to a recent study co-authored by U of T researchers.

Cell manipulation involves the movement of cellular material from one place to another. This technique has been a critical component of numerous research studies in life science areas, including fertility, food science, and physiology.

Limitations of an established existing method

Previously, researchers relied on more invasive techniques to manipulate cells. One method has been the application of optoelectronic tweezers (OET), which creates patterns of light on a photosensitive surface to move microscopic particles.

But as OET uses light to directly engage with the object, according to Postdoctoral Fellow Dr. Shuailong Zhang, this interaction might affect certain biological functionalities. In other words, OET could change the behaviour of living cells — especially by damaging individual biological cells and nanoparticles.

To overcome the limitations of OET, the U of T research team engineered micro-robots to manipulate singular cells with less direct interaction. Zhang, who is the paper’s primary author, led the team alongside Dr. Aaron Wheeler, a professor at U of T’s Department of Chemistry. 

How micro-robots address the pitfall of OET

Projected patterns of light are used to direct the micro-robots. The robots then ‘scoop up’ cells or other microscopic particles, which researchers can then isolate from the biological system.

Due to the advantages that these micro-robots provide researchers over OET, this novel technique can be extensively harnessed in studies that analyze single cells.

“The difficulty with OET was that it interacted with the object [under manipulation], which could affect certain biological functions,” said Zhang. “However, with micro-robots, this interaction is restricted and the object can be transferred with greater intensity and accuracy.”

A popular design for the micro-robots is a cogwheel shape. However, due to the straightforward manufacturing requirements of the robots, they can easily be designed as different shapes.

Micro-robots were a product of an interdisciplinary effort

U of T is regarded as a powerhouse for research, with thousands of students interested in different careers in science, technology, and engineering. With that in mind, Zhang reflected on the interdisciplinary nature of the research environment that produced micro-robots.

A major challenge that his team faced was deciding how everyone can work together effectively: the team had experts from numerous fields, such as biology, engineering and physics.

Working together and understanding each other in such a multidisciplinary environment posed a challenge. Overcoming the challenge, and greatly benefiting from the team’s diversity, enabled the researchers to coordinate and engineer an innovation that could advance single cell research.

Chemistry PhD student named 2019 Vanier Scholar for innovative research proposal

Austin Marchese recognized for his exceptional leadership and scholarly research

Chemistry PhD student named 2019 Vanier Scholar for innovative research proposal

Austin Marchese, a U of T Organic Chemistry PhD student supervised by Professor Mark Lautens, has been named a Vanier Scholar — one of Canada’s most prestigious awards for students in doctoral studies.

Marchese was awarded the scholarship for his research proposal “Novel Enantioselective Nickel-Catalyzed Transformations Forming Medicinally and Industrially Relevant Halogenated Compounds.”

The proposal details his findings that affordable nickel-based catalysts — which can speed up the rate of a chemical reaction without being consumed — could be used in an innovative way to produce compounds important in medicine and industry.  

The impact of Marchese’s research

Writing to The Varsity, Marchese explained that the first part of his research proposal explored a “unique phenomenon” that he and his colleague observed in the course of their research.

“We discovered a rare and intriguing method to generate our compounds with moderate enantioselectivities,” he wrote. An enantioselectivity is a tendency for a reaction to produce one particular variant of a product, in greater quantities than another.

“We would like to understand why exactly we see this phenomenon and how we can exploit it and improve upon it,” he added. “A breakthrough in this would yield a useful and interesting synthetic technique to generate these divergent medicinally relevant compounds with high enantioselectivities.”

The second part of the proposal is to develop improved methods to form bonds between carbon and fluorine. “This methodology would be of interest to pharmaceutical researchers,” noted Marchese, “as carbon-fluorine bonds are ubiquitous in biologically active compounds, but there is a severe lack of synthetic methodologies available to install these bonds in a mild and selective manner.”

“In an ideal world, both parts of my proposal would come together; a nickel catalyzed process of this nature to enantioselectivity generate medicinally relevant compounds while installing an invaluable carbon-fluorine bond, but we are quite far away from achieving this.”

The positive attitude of an organic chemist

Marchese attributed his ability to overcome challenges during his doctoral studies to his passion for his research.

“I believe if you genuinely enjoy what you do and have confidence in yourself,” wrote Marchese, “everything will turn out alright.”

“Many people in my field do very long days, but if you enjoy it does not feel like work. It is similar to the lessons I learned competing Varsity track and field in undergrad; you put in a lot of work so those short instances of success become more rewarding, and that propagates you to work harder after.”

“Expectations do go up in grad school, and you have less time to study and work between deadlines, so I just try to stay calm and trust that if I give it my best and put in as much effort as I can, everything will work out.”

What does a scientist look like?

Seven U of T students discuss their passions and paths in science

What does a scientist look like?

W hat does a scientist look like? For many, the answer involves white lab coats, goggles, and beakers. Yet the people who pursue science are just as diverse as the field itself. Scientists can be activists, athletes, artists, or all of the above. Science can happen indoors or outdoors, under the night sky, or on the internet. Read about the journeys of seven student researchers at U of T.


“As a little girl, I saw a shooting star, and that made the night sky my favourite view. I thought a lot about what was up there and how cool it would be to go to space. This led to my studying physics and astronomy in undergrad and I have never looked back since then.

I currently seek to understand the early universe and how it transitioned to the stars and galaxies we see today. Specifically, what happened in the [epoch] of re-ionization. The epoch of re-ionization is a period in the universe’s history over which the matter in the universe ionizes again.

[My dad] taught me always to strive for more, that there could always be a way if there is a will. He taught me to never give up and to always ask questions. My curiosity in life and career comes from him.”

— Margaret Ikape, first-year PhD in Astronomy and Astrophysics, email


 “I have always been interested in science, but also equally interested in the arts. I went to an arts middle school and high school where half my day was spent doing art and not academics. I spend a lot of my time outside of school engaging in the arts. I still consider myself an artist as much as I consider myself a scientist. It took me a while to come to terms with the fact that I can [be] both.

When I decided I wanted to go to university, I chose to study science since I liked it and was good at it. Moving into my later years of my undergrad I found that I was drawn to ecology courses, field courses, and also really liked the people I met in those classes.

I am interested in the pollutants, that comes from roads, such as road salt, and how it impacts the animals that live in nearby streams. I also study other pollutants that come from roads, such as metals, polycyclic aromatic hydrocarbons, and small bits of car tires (tire dust).”

— Rachel Giles, first-year Master’s in Ecology and Evolutionary Biology, email

“Initially I had my heart set on being a professional dancer and veterinarian (a very practical dual career). Science had been my academic focus for some time, but it took several years after completing my BSc for me to realize that I passionately loved research and applying the scientific method to various questions of animal behaviour and cognition. I had this epiphany while I was juggling three jobs as a lab manager, veterinary assistant, and dog trainer. Out of all of those, I found research to be fulfilling and exciting and it was something I could see myself doing for the rest of my life.

I want to know how [dogs] perceive the world and how they process cues and information present in the environment. I am motivated by the hope that my research can possibly help change how people view dogs, give greater value to them through the recognition of their mental abilities and ultimately lead to greater wellbeing and better access rights in North America.”

— Julia Espinosa, second-year PhD in Cognitive Psychology, email

Julia Espinosa (left) and Madeline Pelgrim (right) work with dogs like Loki to determine animal behaviour. ASHIMA KAURA/THE VARSITY

“Julia Espinosa, the graduate student in my lab, has had the greatest influence on my career. She has been endlessly patient with me since we began working together in the fall of 2016, and has pushed me to advocate for myself and not be afraid to try something new. I would not be at this point in my career without her sage advice and constant confidence.

Like many other students, I had a bit of a rough transition into University in my first year. Adjusting to life away from home (my hometown is a 10 hour drive from Toronto) and everything that comes with living on your own for the first time caused my academics to suffer. When I first applied to join my lab, I was confident that I would not be accepted because of my marks. I am very thankful for my Principal Investigator — Dr. Buchsbaum — and the lab manager at the time — Kay Otsubo — for taking a chance on me and overlooking my performance first-year.”

— Madeline Pelgrim, fourth-year Bachelor’s in Psychology and Biology, email


“There are definitely a lot of challenges throughout a PhD. I would say the biggest one for me were the mental challenges at the early stage of my PhD. How do I keep being confident in front of the language barrier, failure experiments, competitions, and where is my direction for the future? Having been through such a mental struggling stage, I am now clearer of myself, and ready for unknowns.

I always want to help bring positive impacts to our future world. I like the discovery and innovation side of research studies and its potential impact on our better world. My research is to design advanced photo-responsive nanomaterials that can store solar energy into chemical energy by catalyzing the conversion of greenhouse gas carbon dioxide to useful chemicals and fuels. It is a promising solution to reduce the usage of fossil fuels and global warming caused by greenhouse gas.”

— Yuchan Dong, fifth-year PhD in Materials Chemistry, email


“As a child while it was true that I was always curious about nature and the world around us — Asking questions like why is the sky blue? How are clouds formed? etc. It was only when I got older and started to understand ‘what is science? what are scientists? How is science performed?’ that I gained a tremendous passion for it.

This notion that with a few chemical reactions, chemists can ‘creatively’ and rationally generate a molecule which when administered to human can halt disease progression, pain and even extend life — was a very powerful catalyst for my interest in medicinal chemistry. My work mainly focuses on the development of novel small-molecules that specifically target disease-causing cellular components which have been shown to cause certain cancers.

I think as with any budding student of science, whether in graduate studies, professional programs or even out in the workforce, the biggest challenge is to become comfortable with and know how to effectively deal with failure and hardship. As a scientist, at times we learn more from failed experiments than successful ones.”

— Yasir S. Raouf, third-year PhD in Organic and Biological Chemistry, email


“I’ve been both playing sports competitively and going to school since I was six years old. Honestly, if I didn’t play water polo I don’t know what I would be doing in the evenings — I think I would just be sitting on my phone doing nothing. I love to represent Canada, and it’s a really exciting opportunity to do so on an international stage. Looking forward to the future, it would be an honour to represent Canada at the Olympic Games. U of T has opened so many doors for me, with research and athletics.

Initially I came to U of T and I wanted to do Genetics and Cell & Systems Biology — all that nitty gritty stuff. Then I took BIO230, and I was like this is not for me. I was trying to figure out a field where I could apply Life Science techniques, but without wet lab stuff. I had the opportunity to do an ROP [Research Opportunity Program] in Pascal Tyrrell’s lab — which is focused on medical imaging and statistics — and just fell in love with it.”

— Rachael Jaffe, third-year Bachelor’s in Global Health, Statistics, and Economics, spoken

In conversation with Professor Cynthia Goh

Chemistry professor bridges passions for research and entrepreneurship

In conversation with Professor Cynthia Goh

Professor Cynthia Goh balances many responsibilities. She is a professor in the Department of Chemistry, the Department of Materials Science and Engineering, the Institute of Medical Science, and the Munk School of Global Affairs.

She is the director and founder of the Impact Centre, which strives to bring “science to society” through entrepreneurship, and also the academic director of University of Toronto Entrepreneurship.

Goh describes herself as “a STEM student through and through.” Explaining her interest in STEM, she says, “I think if you know the rules that govern the world you can make a better world.”

Goh’s research interests lie in nanoscience — specifically, the properties, structures, conformations, and interactions of molecules such as polymers and biomolecules, and how these molecules can be used to improve areas such as health care and disease treatment.

After receiving tenure, she shifted her focus to entrepreneurship. “I was making impact in my discipline, I would write a paper and people would quote it and write papers about it. But, I really wanted to see how to make a difference in people’s lives and I learned, basically, that’s about bringing this nice research result to creating a product that somebody can use.” This is how the Impact Centre was created.

The Impact Centre was recognized by the university in 2013, but it has been in operation for years prior to that. Goh describes the centre’s mission as striving to connect the research being done in institutions to a service or a product to create positive impact.

In its beginning stages, Goh had designed an extracurricular entrepreneurial skills training program for students who believed that the skills would be of value to them.

But according to Goh, there was a disconnect between research and application. The change in direction was a challenge. However, Goh views challenges as opportunities to overcome obstacles and forge paths to new areas.

In fact, when Goh began working at U of T, she was the only woman in the Department of Chemistry, and this continued for eight years.

“When I had my kid, nobody knew what the maternity leave rules were because nobody has asked for maternity leave before me,” says Goh. She recounts that she would carry her child at work and would, at times, receive strange looks.

But instead of “carrying a chip on [her] shoulder,” she explains, “I’ve always had the attitude that if people maybe may sound like they’re not on your side, it’s probably because they just don’t have the experience.”

From the small sample of children Goh has worked with, she says that despite the generalization that boys seem to have more outward confidence than girls, “confidence comes from having done your homework.”

The nature of STEM subjects, she says, allows for checking if an answer is correct. “In math, you can tell what the correct answer is, so I can build a lot of confidence knowing I’m right.”

Researchers win $3 million grant to develop prenatal test

The Wheeler Lab’s test is a safer alternative to current testing methods

Researchers win $3 million grant to develop prenatal test

For families expecting a child, prenatal testing can help parents identify genetic abnormalities in the fetus before the mother enters labour.

But the current “gold standard” prenatal tests, said PhD student Julian Lamanna of the Wheeler Lab, are burdened with a “small but significant risk to both the mother and the baby.”

Amniocentesis, one of the two tests, is associated with miscarriage in about 0.1 to 0.3 per cent of cases, while the other, chorionic villus sampling, risks miscarriage in about 0.2 per cent of cases.

These serious risks of prenatal screening may be avoided in the future, if the research of the Wheeler Lab succeeds in developing its alternative testing procedure.

On February 4, the lab earned a $3 million grant to continue its development of an alternative non-invasive prenatal test from Genome Canada, a non-profit funding agency supported by the federal government.

How does the Wheeler Lab’s prenatal test work?

The test is similar to a “pap smear” used to screen for cervical cancer, explains Lamanna. In a pap smear, a practitioner scrapes away cells from a woman’s cervix, a part of the uterus that widens during childbirth for the passage of a baby, to test for cervical cancer.

In the Wheeler test, a practitioner would similarly use a “soft, bristly brush” to swab the cervix of a pregnant mother. The collected sample would be a “mixture of cervical mucus, as well as a small percentage of cells from the fetus, as well as a large number of cells from the mother.”

The challenge of analyzing the sample is a “needle-in-a-haystack” problem, explains Lamanna. Visualizing a “sticky mixture of mucus that’s very difficult to work with,” clinicians may have to isolate a single cell from the fetus from the one to two thousand sourced from the mother.

“So we need to use a method to differentiate between the two cell types, and then try to use a method to collect only that cell from the fetus,” said Lamanna. “But I think we have a good method of doing so.”

The method to isolate the fetal cells in the sample uses various antibodies – or molecular tags that act as biomarkers – to highlight their cells of interest. The researchers then use a platform that applies a laser to lyse — or break down — these individual fetal cells in the diverse cell population.

The researchers then collect the contents of these lysed fetal cells, amplify the genetic material available for testing, and analyze the material for abnormalities with a “downstream genetic test” currently used in hospitals.

Next steps with the Genome Canada grant

The instrumentation to lyse the cells and collect their contents is unique to the Wheeler lab, and results from phase one funding for the prenatal test project. The phase-two funding from the Genome Canada grant will enable the researchers to scale up the number of samples it can use for analysis, to further compare its method to current methods.

The grant will also enable the team to develop its platform to become more user-friendly for clinicians, which could enable it to be used in hospitals in Toronto, and even throughout Canada.

Doing so will also help keep the costs of the test low, and could even be comparable to the price of current prenatal tests.

The Wheeler Lab’s main goal is to develop “user-friendly instruments that can leave the research lab,” said Lamanna.

Team effort led to project’s success

Lamanna attributed the project’s success to his motivated colleagues, from a wide range of fields.

As Lamanna worked on the biological side to isolate cells in samples, other lab members worked with “different chemicals and assays… to answer a lot of different biological problems.”

Some team members worked on designing the hardware and instrumentation to isolate the cells and isolate their contents, while others worked on the software.

On the clinical side, the Wheeler lab also collaborated with Dr. Elena Kolomietz and Dr. David Chitayat from Mount Sinai Hospital, who collected cell samples for analysis.

“There’s a big team of people that work on this project,” said Lamanna. “I think everyone who works on is super enthusiastic about the potential for the potential positivity of this test, not only in Toronto, but in Canada, and in the rest of the world.”


Simulating climate change in the lab

New chemistry experiments teach students the effects of greenhouse gases

Simulating climate change in the lab

The role of greenhouse gases in climate change is often misunderstood by the public. Most people know that climate change is caused by increased emissions of greenhouse gases. However, many don’t understand how — for example — carbon dioxide traps heat in the atmosphere. 

U of T chemistry professors Jessica D’eon, Jennifer Faust, Kristine Quinlan, and Scott Browning are acutely aware of this knowledge gap and have developed a lab to address it. Their findings were published in the Journal of Chemical Education. 

The researchers designed a first-year chemistry laboratory on the greenhouse effect that provides a topical and engaging introduction to the undergraduate student laboratory. 

The relatively simple experimental design allows students to focus on grasping complex, big picture concepts without feeling anxious about measurements or dangerous chemicals.

Despite climate science being taught in primary and secondary schools, researchers from Purdue University found that most students enter post-secondary education with a fragmented understanding of the climate system. 

D’eon agrees with the findings of this study, writing that many of her students have “put [the mental model] together in a way that is not scientifically sound” and that generally “the greenhouse gas effect has been identified as a poorly understood concept in climate science.”

Now, these tangible experiments are giving students the ‘aha’ moment that they rarely experience when untangling complex and abstract concepts. As students move on from this course to pursue careers in science and non-science disciplines, they will do so with a fundamental understanding of greenhouse gases.

In the first experiment, students are asked to recognize phase changes using dry ice —  solid carbon dioxide. Here, they develop a sense of scale while improving their qualitative observation skills. 

In the second experiment, students compare types of radiation and energy, discussing their relative importance for the greenhouse effect.

 They then apply this knowledge by comparing the heating rates of two ‘beaker Earths’ — one containing a normal atmosphere and another enriched with carbon dioxide. The students observe firsthand the faster rate of warming in the latter beaker, which they can relate back to their studies. 

Reflections before and after the experiments indicate that, upon completing this lab, 87 per cent of students significantly improved their mechanistic understanding of the greenhouse effect.

 Prior to the experiments, most students gave an unscientific description of greenhouse gases or were too vague in their explanations. After the experiments, students gave more detailed, scientific responses. 

Improving students’ fundamental understanding of greenhouse gases contributes to a better-informed future generation of voters who will make critical decisions about how our society tackles climate change.