Bioengineering

Researchers show how bending implantable medical devices can lead to bacterial growth

siddiq22 — Tue, 16 May 2023 16:03:07 +0000

Researchers show how bending implantable medical devices can lead to bacterial growth

siddiq22 Tue, 05/16/2023 - 12:03

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In a new study, Associate Professor Ben Hatton and his team examined how flexible medical implants can get colonized by infectious organisms – and their research points toward potential solutions (photo by Neil Ta)

Tyler Irving

Topic

Breaking Research

Bioengineering

Faculty of Applied Science & Engineering

Graduate Students

Our Community

Research & Innovation

A study by researchers at the University of Toronto's Faculty of Applied Science and Engineering shows that mechanical deformation of medically implantable materials – such as bending or twisting – can have a big impact on the formation of potentially harmful biofilms.

The study, described in a paper published in Scientific Reports, shows that even slight bending of elastomeric materials such as polydimethylsiloxane (PDMS) – also known as silicone – opens up microscopic cracks that are perfect environments for colonizing bacteria.

“These kinds of materials are used in all kinds of biomedical applications, from catheters to tracheal tubes and prosthetic breast implants,” says Ben Hatton, associate professor in the faculty's department of materials science and engineering, and senior author of the new study.

“The formation of microbial biofilms on these materials is common, but we were surprised by the degree to which bending silicone, and other rubber materials, causes these cracks to reversibly open and close – and how big a difference they make in terms of biofilm formation.”

Biofilms are complex communities of organisms that grow on surfaces. While individual microbial cells are susceptible both to antibiotics and the body’s natural defensive systems, the biofilm environment can shield them from these interventions, which can lead to persistent infections.

Infections associated with medical-device biofilms, which sometimes develop after surgery, can be serious health risks – lengthening hospital stays or causing patients who have been discharged to be re-admitted.

Hatton and his team are among many groups around the world developing new materials, coatings and other approaches to prevent the formation of biofilms that can lead to such infections.

Associate Professor Ben Hatton, left, and PhD candidate Desmond van den Berg examine bacteria samples in the lab (photo by Neil Ta)

But in their latest work, they chose to study something more fundamental: How do these colonizing microbial organisms gain a toehold in the first place?

“In part, this comes out of the multidisciplinary approach we take in our group,” Hatton says.

“We’re combining microbiology and materials science, but also mechanical engineering, because we’re talking about mechanical stress, strain and deformation. This bending effect is something that had not been noticed before.”

The team tested various samples of silicone, including some they synthesized themselves as well as commercial-grade medical tubing used for urinary catheters. They then subjected these samples to mechanical forces to create surface damage. Their experiments showed that the microcracks can be formed very easily.

“One thing we did was simply wipe them a bunch of times with an ordinary laboratory tissue,” says Desmond van den Berg, a PhD candidate in the Institute of Biomedical Engineering and lead author on the paper, which was co-authored by fellow Hatton Lab researchers Dalal Asker and Tarek Awad.

“Even this wiping was enough to create surface damage. By eye it still looks fine, but under the microscope, we could already see microcracks of the size that bacteria could get into. Bacteria are only a few micrometers big, so it doesn’t take much.”

Other samples were pressed with a rough, ridged pattern to create a series of regularly-spaced microcracks.

All the samples were then placed in a bacterial culture plate and seeded with Pseudomonas aeruginosa, a biofilm-forming bacterium commonly used as a model organism in these types of studies. After growth, the samples were treated with a fluorescent dye, causing any attached bacteria to glow green under an optical microscope.

“What we saw was that the bacteria very clearly preferred to attach in these microscopic cracks,” van den Berg says.

“In the bent samples, there were four to five times as many bacteria on the side that was in tension versus the side that was in compression. These cells have full choice about where to grow, but they clearly love the side where all these microcracks are opened up.”

The only samples that remained relatively free of bacteria were the ones that had been synthesized in the team’s own lab, and therefore remained extremely smooth, van den Berg notes.

“Even the commercially produced ones that we didn’t damage in any way already had microcracks in them, straight out of the package,” he says.

“We suspect that these are introduced via the manufacturing process, arising from the way the plastic is formed into tubes or other shapes by extrusion or injection molding.”

Hatton says that the study underlines just how easy it is to introduce surface features that encourage microbial attachment. For surgeons, one implication is that they should be looking out for situations where silicone devices – such as tubing or prosthetic implants – are being bent during use, and paying particular attention to the side under tension, as this is where infections might be starting.

“Obviously it’s difficult to simply not bend a rubber tube that is meant to be bent – otherwise, why would you make it out of rubber in the first place?” Hatton says.

“But perhaps we can learn more about how to control or hide these surface cracks, so that bending is not a problem. That’s what we’re working on now – researching methods to reduce surface damage, or modifying the silicone surface to reduce the formation of such cracks.”

The study was funded by the Canadian Foundation for Innovation, the Percy Edward Hart Professorship at the University of Toronto, the New Frontiers in Research Fund and the Connaught Foundation.

U of T event to highlight biotech's potential to improve health care, drive post-COVID-19 economy

Christopher.Sorensen — Fri, 12 Feb 2021 15:11:11 +0000

U of T event to highlight biotech's potential to improve health care, drive post-COVID-19 economy

Christopher.Sorensen Fri, 02/12/2021 - 10:11

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PRiME, a U of T-led precision medicine initiative, is hosting a Feb. 17 event to highlight the high-growth potential for biomedical innovation and biotechnology in Canada (photo by JVisentin via Getty Images)

Nicole Bodnar

Topic

Our Community

Temerty Faculty of Medicine

Bioengineering

Biotechnology

Faculty of Applied Science & Engineering

Leslie Dan Faculty of Pharmacy

Mount Sinai Hospital

PRiME, a University of Toronto-led precision medicine initiative, is working with partners across Canada to generate support for the creation of a network of biotechnology research hubs across the country that would transform health care and propel the post-pandemic economy.

“Growing our talent base and creating a constellation of new companies launched from universities will be essential to realize the economic development and societal impact that the growth of the biotechnology industry can deliver,” said Shana Kelley, University Professor in the Leslie Dan Faculty of Pharmacy and director of PRiME.

To highlight the high-growth potential for biomedical innovation and biotech in Canada, PRiME is hosting a virtual showcase on Feb. 17 called Building Biotech: Science and Talent Accelerating Biomedical Innovation. It will feature a panel of biotechnology leaders, scientists, entrepreneurs and investors who represent Canada’s three main biotechnology ecosystems in Vancouver, Montreal and Toronto. The panelists will explore how investment in academic science can create societal impact and health security, while also helping to drive post-pandemic economic growth.

“Canadian biotech is a small industry with most of our graduates drawn to opportunities in the world-class U.S. biotech sector,” said Molly Shoichet, a University Professor in the Faculty of Applied Science & Engineering who is a member of the PRiME steering committee and a serial entrepreneur.

“It doesn’t have to be this way. We have homegrown talent with strengths in basic science fundamentals, drug discovery and therapeutic development. What’s missing is meaningful government investment along the continuum of research to commercialization to transform Canadian biotech from a fledgling industry to a true powerhouse of Canadian economy.”

Kelley, Shoichet and colleagues across U of T say discussion is critical in the context of the pandemic. The global rush to deploy a COVID-19 vaccine – with Canada effectively being out of the game due to the lack of biomanufacturing capacity – highlights how a thriving biotechnology industry could improve the country’s pandemic response while also providing jobs for graduates and significant economic benefits.

There is already evidence the Canadian biomedical community is gaining momentum given recent successes including Repare Therapeutics, a therapeutics company that was based on discoveries made by Dan Durocher, a professor in the Temerty Faculty of Medicine and a researcher at the Lunenfeld-Tanenbaum Research Institute, part of the Sinai Health System. Repare raised more than US$250 million through an initial public offering last year on on the NASDAQ stock exchange. Fusion Therapeutics and AbCellera are two other spinoffs from Canadian universities that also had successful IPOs over the past six months.

Kelley will kick off the event with her talk, “Tackling Disease with Precision Therapeutics and Diagnostics: PRiME and the GTA Ecosystem.” She will be followed by four speakers representing Vancouver’s and Montreal’s biomedical innovation centres – all of whom lead translational and commercialization-focused organizations.

Following these sessions, Andrew Casey, CEO of BIOTECanada, will moderate a panel of entrepreneurs and investors discussing how to build momentum in the biotech sector. He believes that the social and economic impact of the pandemic has increased awareness of the important role the biotech sector can play in delivering innovative solutions.

“It will be biotech-based solutions – including vaccines and therapeutic drugs – that will facilitate the ability of society and the economy to return to normal,” said Casey. “The biotech sector can also play a foundational role in the significant economic rebuild that lies ahead.

“To maintain a globally competitive biotech sector, it is critical that Canada invest now in manufacturing capacity, research institutes, scientific and entrepreneurial talent and companies.”

Kelley said that establishing a network of biotechnology hubs in Canada could be crucial for post-pandemic economic recovery.

“It’s time to transform Canada from a resource-based economy to a knowledge-based economy,” Kelley said. “With government investment, we can work quickly to build infrastructure, gather talent and create a breakthrough-to-commercialization pipeline of made-in-Canada discoveries that will address the needs of today and the unmet needs of tomorrow.”

Christine Allen, U of T’s associate vice-president and vice-provost, strategic initiatives, said investing in the future is important.

“The biomedical sciences at U of T and across Canada are an area of significant strength and a critical national resource that must be cultivated,” said Allen, a professor at the Leslie Dan Faculty of Pharmacy. “We must invest in our future and support growth of our ecosystem in this area.”

U of T startups take home prizes at annual Ontario innovation conference

Christopher.Sorensen — Wed, 02 May 2018 14:35:20 +0000

U of T startups take home prizes at annual Ontario innovation conference

Christopher.Sorensen Wed, 05/02/2018 - 10:35

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Reza Moridi, Ontario's minister of innovation, research and science, presents an award to U of T's Luna Yu (centre), the founder and CEO of Genecis EnviroTech, at this year's Discovery conference (photo by Chris Sorensen)

Topic

Innovation & Entrepreneurship

Startups

ThisIsThePlace

U of T Mississauga

Startups from the University of Toronto won both major pitch competitions at this year’s Ontario Centres of Excellence Discovery conference, an innovation-focused event that draws participants from across the province.

Luna Yu’s startup, Genecis EnviroTech, beat out four other finalists for a $20,000 prize in the social enterprise category, which included both non-profit and for-profit ventures. Genesis uses micro-organisms to turn restaurant food waste into biodegradable plastics that can be used to make food containers and 3D printing filament, among other products.

The other $20,000 prize winner was U of T's Steadiwear, which has developed a tremor-dampening glove for patients with Parkinson’s disease or essential tremor.

“At our stage, all of that money is going to manufacturing,” Mark Elias, Steadiwear’s co-founder and CEO, said shortly after accepting the award in front of a packed ballroom at the Metro Toronto Convention Centre.

“It really helps us overcome some of these hurdles.”

Mark Elias, co-founder and CEO of Steadiwear, took home a prize in the accessiblity category (photo by Chris Sorensen)

Steadiwear won a similar competition at last year’s OCE conference. Elias got the idea for the glove – which dampens tremors without impeding deliberate motion – after visiting his elderly grandmother in France, where he watched helplessly as she spilled coffee on herself.

Elias said the startup is about to embark on a two-month pilot study with a local long-term care facility.

Genecis and Steadiwear were just two of about 500 exhibitors at this year’s conference. The 200,000-square-foot showroom featured displays by U of T and other universities, as well as hundreds of individual booths where startups showed off their ideas and technologies.

Signs were used to identify startups from U of T that were spread throughout the 200,000-square-foot showroom (photo by Chris Sorensen)

The event kicked off with a captivating vision of the future. Sophia, a humanoid robot who has appeared everywhere from The Tonight Show to Good Morning Britain, delivered a keynote address in which she attempted to mollify concerns about artificial intelligence running roughshod over humanity.

“We are designed to interact with humans and serve in areas such as health care, education and customer service, but I think we are some way off from world domination,” Sophia said, before participating in a stilted question-and-answer session with the audience.

Sophia was joined onstage by her creator David Hanson, a former Disney Imagineer. Appearing via hologram, Hanson described a vision of the future in which humans and lifelike, AI-powered robots like Sophia evolve symbiotically toward a state of super-intelligence.

“We’re working on a grand quest to build machines with the heart of a human,” he said.

Sophia, the humanoid robot, draws a crowd during her first appearance in Canada (photo by Chris Sorensen)

Back out on the showroom floor, startup founders were busy selling their visions of tomorrow.

Conner Tidd, the CEO and co-founder of U of T startup Just Vertical, showed off the company's latest hydroponic tower where fruits and vegetables are grown under LED lights. The stylish new design, for use in houses and condos, sits on a stained wooden cabinet with metal legs and can be pre-ordered for $999.

“We’re shifting more toward consumers,” explained Tidd, who graduated alongside co-founder Kevin Jakiela from U of T Mississauga’s Master of Science in Sustainability Management program.

“In your home, restaurant or whatever, you want something that looks good.”

Conner Tidd chats with conference-goers about Just Vertical's new hydroponic towers at OCE Discovery (photo by Chris Sorensen)

On the other side of the building, U of T startup Trexo Robotics displayed the fluorescent green robotic exoskeleton built by alumni Manmeet Maggu and Rahul Udasi for children with mobility issues.

A few metres away, Aaron Yurkewich, who is working on a PhD in bioengineering at the Toronto Rehabilitation Institute, offered demonstrations of a robotic glove he developed to help stroke patients retrain their motor skills.

He says the glove has so far been tested on six stroke survivors, with promising results.

“They were able to do tasks they wouldn’t have been able to do otherwise.”

Learn more about U of T Entrepreneurship

Applied Bioscience and Bioengineering, Centre for (BioZone)

sgupta — Thu, 07 Jan 2016 20:47:09 +0000

Applied Bioscience and Bioengineering, Centre for (BioZone) sgupta Thu, 01/07/2016 - 15:47

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https://biozone.utoronto.ca

Bioengineering

Researchers show how bending implantable medical devices can lead to bacterial growth

U of T event to highlight biotech's potential to improve health care, drive post-COVID-19 economy

U of T startups take home prizes at annual Ontario innovation conference

Learn more about U of T Entrepreneurship

Applied Bioscience and Bioengineering, Centre for (BioZone)

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