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Biophysicist in Profile

Michel Lafleur

Michel Lafleur

May 2017 // 4161

Michel Lafleur describes himself as, “one of those kids who got interested very early in science. When I was about 10, I spent incalculable hours in our basement playing with my chemistry kit, amazed by the change of color of a flame when different salts were sprinkled, trying to make my rocket lift as high as possible with a mixture of vinegar and baking soda.” His father was a welder and quite a handy man, fixing anything in the house that needed repair. His mother worked at home, raising Lafleur and his two brothers and managing much of the household labor. “I inherited their enjoyment of work well done,” he says, “but there is no science gene.”

He followed a science track in high school and then entered the chemistry program at Université de Sherbrooke in the Eastern Townships of Québec without hesitation. When he started at university, he did not plan on pursuing a PhD, but an undergraduate research opportunity opened his eyes to that idea. “The department has a co-op program and I had the opportunity to spend a summer in a research laboratory with Professor Jean-Pierre Caillé,” he shares. “I studied the variation of sarcomere length as a function of the ionic strength using a diffraction method. This project was in collaboration with Professor Michel Pézolet, at Université Laval, in Québec City; Michel was looking at the change in protein secondary structure during muscle contraction by Raman spectroscopy. This is how I met him and decided to join his group for a PhD.”

Lafleur’s doctoral project was to examine whether melittin, a peptide from bee venom, could induce a phase separation in lipid bilayers, using mainly Raman spectroscopy. “It was at a time when there was a big debate about boundary lipids around transmembrane peptides, a controversy that was essentially due to the timescale that people were considering,” he says.

Following his PhD studies, he went to the University of British Columbia to join a project with Myer Bloom and Pieter Cullis. “Myer was a leader in the development of deuterium solid state NMR for soft materials such a lipid bilayers while Pieter pioneered the use of phosphorus NMR to study lipid polymorphism,” he says. Lafleur’s project was to find out any information about lipid polymorphic propensities that could be obtained by deuterium NMR. “The great thing was that we got an agreement with Avanti Polar Lipids so I prepared a batch of deuterated palmitic acid and they made POPC and POPE with deuterated palmitoyl chain,” he shares. “In those days, deuterated phospholipids were not commercially available and getting this valuable material put us in an enviable position.” They were able to detail the impact of various parameters on the order profile of lipid acyl chains. At the end of his postdoc appointment, putting together the NMR data and x-ray diffraction measurements from Sol Gruner's group, then at Princeton, they were able to propose a model that bridged the dimension of inverted hexagonal phase and acyl chain order.

Following his postdoc, Lafleur was offered a position at Université de Montréal, so he returned to his hometown. “Currently, I am a full professor in the chemistry department of the Université de Montréal. I am happy with this position. Montréal has just been identified last February as the best university student city in the world by the Quacquarelli Symonds Institute. It is a stimulating environment to carry out research,” he shares. “Soft materials science is a well-established field in our university so there is an exciting momentum: several great colleagues, a good bunch of enthusiastic students, and a great instrumental infrastructure.”

Lafleur’s lab is currently conducting research in three areas. First, they are working at gaining a better understanding of the relationship between the structure and the function of skin lipids. “Skin involves several lipids that are unusual for biological membranes; these provide a rather unique structure, including a high level of crystallinity, and a rather unusual impermeability, determining both the rate of water loss through the skin, and absorption of exogenous molecules into the body,” he explains. Second, they are studying proteins and peptides that have the ability to extract lipids from membranes. In some systems, such as those involving some toxins, it leads to cell death. In other systems, this process is vital.

Lafleur in front of The Broad museum during the 2016 Annual Meeting.

“We are trying to define the mechanisms of lipid extraction induced by peptides and proteins with a special focus on its lipid specificity,” Lafleur says. Finally, they are working on translating knowledge about lipid physical chemistry to contribute to the development of liposomes as drug nanovectors. “We have recently participated in the development of a very innovative platform for drug delivery, in a project led by Professor Sylvain Martel from École Polytechnique, in Montréal. We have trapped a drug in liposomes and attached these drug-loaded liposomes to a magnetotactic bacteria. About one million of these bacteria were injected near cancer tumors in mice and were concentrated in the core of the tumors, using magnetic field gradients to guide them,” he says. “This directed drug delivery by ‘nanorobots’ enabled us to obtain remarkable therapeutic effects with relatively small amounts of drug. This exciting project involves engineers, microbiologists, chemists, biochemists, oncologists, surgeons, and pathologists and is a perfect example of multidisciplinary research.”

An ongoing challenge for Lafleur has been keeping a sensible pace and balance among the many aspects of a faculty member’s job. “Research is a very gripping activity. It is also essentially endless,” he notes. Balancing research with a teaching load is not the full picture, given additional commitments that scientists undertake. “The university system and the science system are both functioning based on the considerable involvement of their members. I believe it is our responsibility to get involved so things run well,” says Lafleur. “It can be reviewing manuscripts, grant applications, evaluating theses, sitting on various committees, managing instrumental platforms; I would say that every faculty member can make her/his own list. These add up and a big challenge I find is to avoid packing too many things with tight deadlines as these enjoyable activities can become less pleasurable under time stress.”

Lafleur finds time to bike whenever possible, both around Montreal and on cycling holidays with his wife. “My wife and I spent our last summer holidays cycling about 600 km on the rolling hills of Nova Scotia, in the Atlantic part of Canada. Previously, we cycled around Champlain Lake, on Prince-Edward Island, and around St-Jean Lake in Québec,” he says. “We carry our camping supplies, clothes, food. We find this is one of the best ways to explore an area.”

He also enjoys visiting art museums and galleries, especially those with contemporary art collections. “I can confess that I took advantage of most of the Biophysical Society annual meetings to visit local art museums,” he shares. “Maybe a few people are not so thrilled when the meeting is in Baltimore but, besides the exciting meeting, the Matisse collection of the Baltimore Museum of Art is superb!”