Bioengineering is booming at McGill

Fall 2011

Mining and Materials Engineering Professor Marta Cerruti and PhD student Hesameddin Mahjoubi monitor how molecules found in the body interact with the surfaces of sample biomaterials. Their work has multiple applications, such as reconstructive surgery. See below for details. (Photo - Owen Egan)

Bioengineering is one of the fastest-growing fields in engineering and McGill is moving on several fronts to establish itself as a leader.

A new undergraduate program has been approved by the University and is now under consideration by the Quebec Ministry of Education, planning is underway to establish a Department of Bioengineering and a search has started to hire McGill Engineering’s first endowed chair in bioengineering — the result of a major gift from a generous donor.

Bioengineering has played an important role in McGill Engineering research for at least two decades, and our professors’ expertise spans the entire field — including exploring ways to use bacteria to break down environmental pollutants, creating new materials (such as bioplastics and biodiesel) and developing neural prosthetics that respond to messages from the brain.

The new BEng program will reflect McGill Engineering’s considerable depth in the field and offer undergraduate students an unparalleled interdisciplinary education. The first students are expected to enter the program next fall.

In this issue, we shine the spotlight on some of the professors on our Faculty’s bioengineering team.

Bioengineering — the application of biological knowledge and principles to design structures, materials, devices and processes

Mechanical Engineering Professor Rosaire Mongrain examines a silicon model of a human aorta developed with the assistance of PhD Biomedical Engineering student Soroush Nobari (right). This particular 3D model duplicates the aorta of a 63-year-old woman.

Bioengineering’s versatility — applications span improving health care, addressing environmental concerns and developing safe and sustainable materials — has elevated its profile in recent years. The U.S. Department of Labor has picked bioengineering as the fastest-growing engineering discipline over the coming decade.

Up until now, McGill undergraduates have explored the field through minors in biotechnology and biomedical engineering, or via the Summer Undergraduate Research in Engineering (S•U•R•E) program (see the Fall 2009 issue of the Dean’s Report). With the new BEng program more students than ever will be free to pursue studies in bioengineering.

“The Faculty is well poised for this latest step in its bioengineering evolution,” says Mechanical Engineering Department Professor Rosaire Mongrain, who has collaborated for more than 20 years with cardiologists and heart surgeons in designing and building cardiovascular implants, such as heart valves, stents (a small tube for inserting into blocked vessels), and artificial vessels. See  The 3D Heart.

Inter-department cooperation is a major feature of bioengineering at McGill. Professor Mongrain, from Mechanical Engineering, and Mining and Materials Engineering (MME) Professor Stephen Yue co-supervise the work of MME master’s student Bandar Al-Mangour. Mongrain and Al-Mangour are seen here working with a Tensile Tester in the MME Department’s Hot Deformation Laboratory in the W. H. Wong Building. (Photo - Owen Egan)

Professor Mongrain is one of a core of 29 professors either working primarily in bioengineering or doing significant research in the field, and McGill Engineering will be hiring six more professors working mainly in bioengineering. “So, with high student interest, a strong research core and many partnerships with industry, we have had a lot of potential energy. The new BEng program will convert part of that energy into something concrete.”

Diversity is unique

“Our philosophy is to draw on our wide-ranging research to teach principles that will give students the knowledge base to move between bioengineering clusters — environmental, materials, biomedical and so forth,” says Civil Engineering and Applied Mechanics Department Professor Subhasis Ghoshal, who is also Associate Dean for Undergraduate Education.

“Most other university programs focus on biomedical engineering or biotechnology, so this diversity is unique to McGill Engineering. And it reflects our Faculty’s strengths.”

In addition to a general “Introduction to Bioengineering” and courses in fundamental engineering skills, students will also select from options including “Electrical Circuits for Bioengineers,” “Molecular, Cellular and Tissue Biomechanics,” and “Biosystems and Control.”

Many will undertake industry internships, and all final-year students will carry out a bioengineering design or research project. The result, says Professor Ghoshal: “a graduate with solid interdisciplinary skills and the ability to move across bioengineering fields.”

Professor Ghoshal knows of what he speaks. He is exploring how bacteria can be used to break down petroleum hydrocarbon contaminants, used heavily as industrial solvents.

“People have long believed that bacteria wouldn’t work below zero degrees,” he says. And that is a problem for Canada, given the oil exploration and other industrial activities occurring in northern regions, creating the potential for environmental damage.

Producing biomaterials

However, Professor Ghoshal and his team have discovered bacteria that do work at temperatures below zero if managed well. “And that is the engineering contribution: we are learning how to tweak things so bacteria work efficiently under sub-zero conditions, giving us longer treatment seasons.”

This highly sophisticated bioreactor in Professor Dominic Frigon’s Environmental Community Engineering Laboratory is a miniature version of a municipal wastewater treatment plant. Built on a scale of 1 to 30-million, the apparatus helps him develop technologies to transform liquid waste into valuable industrial by-products. Located in the Macdonald Engineering Building, the laboratory forms part of the Benedek Integrated Laboratories in Environmental Engineering. (Photo - Owen Egan)

As other faculty research shows, bacteria do more than break down contaminants. “Not only can we develop bacterial systems to de-pollute wastewaters, we can also use this waste to create new biomaterials,” says Civil Engineering and Applied Mechanics Department Professor Dominic Frigon.

Like humans, microorganisms can accumulate fat: in their case, in the form of polyhydroxyalkanoate (PHA) or triglyceride compounds, which can then be used to produce bioplastics or biodiesel fuel, respectively.

Currently, industrial facilities generate bioplastics by following precise recipes using specific bacteria to produce these compounds, which can then be harvested. But this is an expensive, time-consuming process that demands a sterile environment.

Professor Frigon, on the other hand, uses the wastewater itself as a source to produce PHAs, even though the precise mix of organisms is unknown.

“Think of wastewater as an ecosystem. We are trying to manipulate this ecosystem to encourage the growth of microbial strains that would produce what we want,” he says. “Because we don’t require a sterile environment, it isn’t costly. In fact, we’re using something that people pay to dispose of, while aiming to create something that people will purchase.”

Professors Ghoshal, Frigon and Chemical Engineering’s Nathalie Tufenkji are among a number of researchers working in environmental engineering and biomaterials. Professor Tufenkji’s research with cranberries (see sidebar below) has also taken her into biomedical engineering, which itself encompasses many diverse activities.

Professor Sam Musallam's team implants sensor arrays into the brains of lab monkeys to detect electrical and chemical neural signals that could be translated to operate prosthetic devices. The images above provide a guide for implanting the arrays.

Exploring brains and bodies

For example, imagine a paralyzed individual who wants to move a computer cursor from one point to another. Sam Musallam, a Professor of Electrical and Computer Engineering and the Canada Research Chair in Bioengineering, is hoping to transform such dreams into reality.

His explorations into cognitive neural prosthetics demand two closely coordinated labs — one in the Electrical and Computer Engineering Department, the other in the Faculty of Medicine’s Department of Physiology — that study how intentions (like the desire to move the cursor) are encoded as electrical and chemical signals in the brain, how to build implants that will detect these signals, how to develop algorithms to decode them and, finally, how to design prosthetic devices that can translate intentions into actions.

Professor Musallam’s laboratory is distinct in many ways: while others focus on decoding motor signals needed to move the cursor through each point along a trajectory, his team focuses on signals representing the intent to move the mouse from one point to another. And, rather than adapting their mechanism to the brain, they hope to teach the brain to learn their algorithms.

“The brain has extremely powerful learning capacities, so we want it to optimize itself to use our prosthetic devices,” he says. “We are using novel ideas where we have started from scratch, so our research is covering a lot of new ground.’’

Electrical and Computing Engineering Professor Tal Arbel (right) with PhD student Nagesh Subbanna (left) discuss her work in image-guided neurosurgery, a collaboration with researchers and neurosurgeons at the Montreal Neurological Institute. (Photo - Owen Egan)

While Professor Musallam’s group is trying to find ways for the brain to talk to computers, Professor Tal Arbel, of the Electrical and Computer Engineering Department, is improving the imaging technology neurosurgeons use during open skull brain operations.

“During image-guided neurosurgery, surgeons refer to Magnetic Resonance Imaging (MRI) pictures of the patient’s brain taken before the operation,” Professor Arbel says.

“Unfortunately, when you open a skull, the brain swells and shifts, and if the patient is on one side gravity comes into play, so locations in the brain are no longer guaranteed to correspond to the pre-op image.”

Her Probabilistic Vision Group works with Montreal Neurological Institute researcher Louis Collins to find ways to match ultrasound images acquired during brain operations to the pre-op MRI, thus providing the surgeon with updated MRI pictures to use for guidance — pictures that have been corrected for the shift.

Her lab is also collaborating with Collins and Dr. Doug Arnold, a neurologist, to develop new imaging techniques for multiple sclerosis, a degenerative disease that attacks and leaves lesions in the brain, predominantly in the white matter.

This MRI image provided by Professor Tal Arbel and her team represents average brain volume. It was compiled from numerous scans of healthy individuals, using data from the International Consortium for Brain Mapping.

Encouraging growth

Their goal is to develop more effective ways of automatically identifying these lesions in MRI scans, enabling physicians to accurately estimate the burden of the disease and explore ways to treat it. “Much of this research can be applied elsewhere,” she says, “so we are starting to look at breast images and are talking to local companies interested in similar problems.”

In the same way, Mining and Materials Engineering Department Professor Marta Cerruti’s research has a wide range of potential applications. Professor Cerruti is developing “scaffolds” to help the body rebuild tissue lost to disease or accident, or accept prosthetic implants.

The scaffolding materials must encourage the growth of the correct type of cells: either mineralized tissues, like bone or teeth, or soft tissues. To this end, she and her team are studying how proteins regulate this mineralization process so they can construct molecules mimicking these functions and then attach them to the scaffold’s porous surfaces. “Scaffolds with these molecules would then be able to direct cells whether or not to promote mineralization,” explains Professor Cerruti, who was named the Canada Research Chair in Biosynthetic Interfaces in October 2011.

The benefits are many: the scaffolding, made from biodegradable polymers, could be used in reconstructive surgery to prompt the body to generate the appropriate tissue — either hard, as in the case of bone, or soft, as with skin and muscle tissues — and then to provide support as the tissue grows. And if used for prosthetic implants, they would integrate with the body and biodegrade as it generates new tissue, so that no artificial materials remain within the body.

Professor Cerruti’s work, like the other research described in this issue, has attracted a steady stream of undergraduate students pursuing research experience, which forecasts an enthusiastic response to the Faculty’s new bioengineering program. Initial plans are to accept between 30 and 50 students, increasing enrolment as new professors are hired and laboratories develop.

“We anticipate tremendous student interest and we already have a great deal of research activity,” Professor Ghoshal says. “So my guess is that the bioengineering program will grow rapidly, like the field itself.”

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Cranberry research addresses health issue

Irwin Eydelnant was an undergraduate student hoping to carry out a research project when he approached Chemical Engineering Department Professor Nathalie Tufenkji, the Canada Research Chair in Biocolloids and Surfaces and Associate Director of the Brace Research Center for Water Resources Management.

Irwin Eydelnant (left), Professor Nathalie Tufenkji and former PhD student Robert Delatolla (right), now a professor at the University of Ottawa. (Photo - Owen Egan)

“Irwin wanted to do a bioengineering project with a medical slant. I normally study bacteria and pathogens in the environment, but because I’m interested in adhesion and surface interactions, I directed him toward bacteria buildup in catheters,” recalls Professor Tufenkji.

“Bacteria can multiply to form a biofilm in catheters, and eventually they can swim up the urinary tract to infect the bladder or kidneys.” Eydelnant had read a study on the impact of cranberry juice, a long established folk treatment for urinary tract problems, and a research project was born.

Working through the term (and, after that, through a master’s degree), Eydelnant and Tufenkji discovered that when one type of infection-causing bacterium is exposed to the cranberry extract proanthocyanidin (or C-PAC), its capacity to adhere to catheter tubing is inhibited.

Further research by postdoctoral fellows Che O’May and Gabriela Hidalgo revealed that C-PAC impairs mobility of different infectious bacteria by affecting the gene responsible for the flagella that allow bacteria to move about.

Professor Tufenkji has continued to pursue the cranberry research, and a recent collaboration with McGill Microbiology and Immunology Professor Samantha Gruenheid suggests that the extract may also reduce gastrointestinal infections.

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