Tag Archives: bioadhesives

Turning marine waste into medical applications

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This 2025 Research Story on the Natural Sciences and Engineering Research Council of Canada website describes work from McGill University to turn marine waste into a bioadhesive, Note: A link has been removed,

An interdisciplinary team of researchers at McGill University has developed an ultra-strong, environmentally friendly medical glue, or bioadhesive, made from marine waste. The discovery has promising applications for wound care, surgeries, drug delivery, wearable devices and medical implants.

“A glue that can close wounds or make something strongly adhere to the skin is critical for many medical interventions,” says Audrey Moores, a chemistry professor at McGill.

A July 31, 2025 McGill University news release, which originated the research story, has more detail to offer, Note: Links have been removed,

“Many existing bioadhesive products are based on toxic compounds, while overall, there is a need to explore new materials that demonstrate both high adhesion and strong fatigue resistance, or the ability to hold even if pulled apart repeatedly,” Moores said.  
 
Moore [sic] and main co-author Jianyu Li, Associate Professor, Department of Mechanical Engineering and Canada Research Chair in Tissue Repair and Regeneration reported their findings in “Nanowhisker glues for fatigue-resistant bioadhesion and interfacial functionalization,” published in Nature Communications.  

Naturally sourced nanowhiskers give the glue its strength 

The new bioadhesive is composed of chitosan, a chemically modified form of chitin, the natural building block found in the exoskeletons of shellfish and certain fungi. 

The researchers modified the chitosan to have a nanowhisker shape – a feature that proved to be essential to the bioadhesive’s effectiveness – using a mechanochemical process pioneered by co-authors Moores and Edmond Lam in previous studies.   

 “We chemically manipulate this material to turn it into nanochitosan, which has a range of different properties we can finetune. Using this nanomaterial, we can make nanoglue,” Moores said. 

Ultrasound turns whiskers into interlocking structures 

To apply the nanoglue, researchers use a unique ultrasound technology developed by the Li group to penetrate the skin.  When exposed to sound waves, the nanowhiskers not only adhere firmly to skin but also interlock into a rigid, resilient scaffolding that drastically enhances the glue’s strength and durability. 

“Imagine you have a Band-Aid on your hand. It’s difficult to get it to stay, because your hand moves a lot,” Moores explained.  

“To get it to stick, you need the skin to be permeable to the glue. We used microneedles or ultrasound for that. 

 “We were surprised to see that ultrasound was critical to making a strong glue. While our initial strategy was to get the nanoglue to stick to the skin, we also discovered ultrasounds helped build a complex, interconnected network of our nanostructures. These nanowhisker glues are simply better than the current glues out there.”  

They say the nanostructure has promising applications beyond health care, in many engineering contexts. 

Allergy-safe, and potentially vegan 

The bioadhesive is also fully biocompatible, even for people with seafood allergies. 

“People who are allergic to shellfish are not allergic to chitin, but the proteins. We can remove these in the manufacturing process and avoid allergic reactions.  
 
“We could also theoretically make a vegan version from fungi,” Moores added. 

…

This research was funded by the Natural Sciences and Engineering Research Council of Canada, the National Research Council Ocean program, the Canada Foundation for Innovation and the National Institutes of Health of the United States, the Canada Research Chairs Program, the Fonds de Recherche du Québec Nature et Technologies (FRQNT) – Centre for Green Chemistry and Catalysis and McGill University.

For those who like to listen to their science news, the Canadian Broadcasting Corporation (CBC) has an 8 mins. 8 secs. radio segment where researcher Audrey Moores is interviewed by Angelica Montgomery. on Quebec AM.

Here’s a link to and a citation for the paper,

Nanowhisker glues for fatigue-resistant bioadhesion and interfacial functionalization by Shuaibing Jiang, Tony Jin, Tianqin Ning, Zhen Yang, Zhenwei Ma, Ran Huo, Yixun Cheng, Davis Kurdyla, Edmond Lam, Rong Long, Audrey Moores & Jianyu Li. Nature Communications volume 16, Article number: 6826 (2025) DOI: https://doi.org/10.1038/s41467-025-62019-y Published: 24 July 2025

This paper is open access.

Safer, greener way to make hydrogels? Try ultrasound

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A May 9, 2025 news item on ScienceDaily announces research from McGill University (Montréal, Québec) and Polytechnique Montréal,

Researchers at McGill University, in collaboration with Polytechnique Montréal, pioneered a new way to create hydrogels using ultrasound, eliminating the need for toxic chemical initiators. This breakthrough offers a faster, cleaner and more sustainable approach to hydrogel fabrication, and produces hydrogels that are stronger, more flexible and highly resistant to freezing and dehydration. The new method also promises to facilitate advances in tissue engineering, bioadhesives and 3D bioprinting

Hydrogels are gels composed of polymers that can absorb and retain large amounts of water. They are widely used in wound dressings, drug delivery, tissue engineering, soft robotics, soft contact lenses and more.

…

A May 8, 2025 McGill University news release (also on EurekAlert but published on May 9, 2025), which originated the news item, provides more details about the work,

…

Gel formation within minutes

Traditional hydrogel manufacturing relies on chemical initiators, some of which can be harmful, particularly in medical applications. Initiators are the chemicals used to trigger chemical chain reactions. The McGill research team, led by Mechanical Engineering Professor Jianyu Li, has developed an alternative method using ultrasound. When applied to a liquid precursor, sound waves create microscopic bubbles that collapse with immense energy, triggering gel formation within minutes. 

“The problem we aimed to solve was the reliance on toxic chemical initiators,” said Li. “Our method eliminates these substances, making the process safer for the body and better for the environment.” 

This ultrasound-driven technique is dubbed “sonogel.”

“Typical hydrogel synthesis can take hours or even overnight under UV light,” said Li. “With ultrasound, it happens in just five minutes.” 

Revolutionizing biomedical applications

One of the most exciting possibilities for this technology is in non-invasive medical treatments. Because ultrasound waves can penetrate deep into tissues, this method could enable in-body hydrogel formation without surgery.  

“Imagine injecting a liquid precursor and using ultrasound to solidify it precisely where needed,” said Li. “This could be a game-changer for treating tissue damage and regenerative medicine. Further refinement, we can unlock new possibilities for safer, greener material production.” 

The technique also opens the door to ultrasound-based 3D bioprinting. Instead of relying on light or heat, researchers could use sound waves to precisely “print” hydrogel structures.  

“By leveraging high-intensity focused ultrasound, we can shape and build hydrogels with remarkable precision,” said Jean Provost, one of co-authors of the study and assistant professor of engineering physics at Polytechnique Montréal.  

Here’s a link to and a citation for the paper,

Ultrasound Cavitation Enables Rapid, Initiator-Free Fabrication of Tough Anti-Freezing Hydrogels by Yixun Cheng, Stephen Lee, Yihang Xiao, Shou Ohmura, Louis-Jacques Bourdages, Justin Puma, Zixin He, Zhen Yang, Jeremy Brown, Jean Provost, Jianyu Li. Advanced Science Volume 12, Issue 22 June 12, 2025 2416844 DOI: https://doi.org/10.1002/advs.202416844 First published online: 17 April 2025

This paper is open access.

Making longer lasting bandages with sound and bubbles

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This research into longer lasting bandages described in an August 12, 2022 news item on phys.org comes from McGill University (Montréal, Canada)

Researchers have discovered that they can control the stickiness of adhesive bandages using ultrasound waves and bubbles. This breakthrough could lead to new advances in medical adhesives, especially in cases where adhesives are difficult to apply such as on wet skin.

“Bandages, glues, and stickers are common bioadhesives that are used at home or in clinics. However, they don’t usually adhere well on wet skin. It’s also challenging to control where they are applied and the strength and duration of the formed adhesion,” says McGill University Professor Jianyu Li, who led the research team of engineers, physicists, chemists, and clinicians.

…

Caption: Adhesive hydrogel applied on skin under ultrasound probe. Credit: Ran Huo and Jianyu Li

An August 12, 2022 McGill University news release (also on EurekAlert), which originated the news item, delves further into the work,

“We were surprised to find that by simply playing around with ultrasonic intensity, we can control very precisely the stickiness of adhesive bandages on many tissues,” says lead author Zhenwei Ma, a former student of Professor Li and now a Killam Postdoctoral Fellow at the University of British Columbia.

Ultrasound induced bubbles control stickiness

In collaboration with physicists Professor Outi Supponen and Claire Bourquard from the Institute of Fluid Dynamics at ETH Zurich, the team experimented with ultrasound induced microbubbles to make adhesives stickier. “The ultrasound induces many microbubbles, which transiently push the adhesives into the skin for stronger bioadhesion,” says Professor Supponen. “We can even use theoretical modeling to estimate exactly where the adhesion will happen.”

Their study, published in the journal Science, shows that the adhesives are compatible with living tissue in rats. The adhesives can also potentially be used to deliver drugs through the skin. “This paradigm-shifting technology will have great implications in many branches of medicine,” says University of British Columbia Professor Zu-hua Gao. “We’re very excited to translate this technology for applications in clinics for tissue repair, cancer therapy, and precision medicine.”

“By merging mechanics, materials and biomedical engineering, we envision the broad impact of our bioadhesive technology in wearable devices, wound management, and regenerative medicine,” says Professor Li, who is also a Canada Research Chair in Biomaterials and Musculoskeletal Health.

Here’s a link to and a citation for the paper,

Controlled tough bioadhesion mediated by ultrasound by Zhenwei Ma, Claire Bourquard, Qiman Gao, Shuaibing Jiang, Tristan De Iure-Grimmel, Ran Huo, Xuan Li, Zixin He, Zhen Yang, Galen Yang, Yixiang Wang, Edmond Lam, Zu-hua Gao, Outi Supponen and Jianyu Li. Science 11 Aug 2022 Vol 377, Issue 6607 pp. 751-755 DOI: 10.1126/science.abn8699

This paper is behind a paywall.

I haven’t seen this before but it seems that one of the journal’s editors decided to add a standalone paragraph to hype some of the other papers about adhesives in the issue,

A sound way to make it stick

Tissue adhesives play a role in temporary or permanent tissue repair, wound management, and the attachment of wearable electronics. However, it can be challenging to tailor the adhesive strength to ensure reversibility when desired and to maintain permeability. Ma et al. designed hydrogels made of polyacrylamide or poly(N-isopropylacrylamide) combined with alginate that are primed using a solution containing nanoparticles of chitosan, gelatin, or cellulose nanocrystals (see the Perspective by Es Sayed and Kamperman). The application of ultrasound causes cavitation that pushes the primer molecules into the tissue. The mechanical interlocking of the anchors eventually results in strong adhesion between hydrogel and tissue without the need for chemical bonding. Tests on porcine or rat skin showed enhanced adhesion energy and interfacial fatigue resistance with on-demand detachment. —MSL

I like the wordplay and am guessing that MSL is:

Marc S. Lavine
Senior Editor
Education: BASc, University of Toronto; PhD, University of Cambridge
Areas of responsibility: Reviews; materials science, biomaterials, engineering

Darwin’s barnacles become unglued

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The world’s strongest glue comes from barnacles and those creatures have something to teach us. From a July 18, 2014 news item on Nanowerk,

Over a 150 years since it was first described by Darwin, scientists are finally uncovering the secrets behind the super strength of barnacle glue.

Still far better than anything we have been able to develop synthetically, barnacle glue – or cement – sticks to any surface, under any conditions.

But exactly how this superglue of superglues works has remained a mystery – until now.

An international team of scientists led by Newcastle University, UK, and funded by the US Office of Naval Research, have shown for the first time that barnacle larvae release an oily droplet to clear the water from surfaces before sticking down using a phosphoprotein adhesive.

A July 18, 2014 Newcastle University (UK) press release, which originated the news item, provides some context and describes the research,

“It’s over 150 years since Darwin first described the cement glands of barnacle larvae and little work has been done since then,” says Dr Aldred, a research associate in the School of Marine Science and Technology at Newcastle University, one of the world’s leading institutions in this field of research.

“We’ve known for a while there are two components to the bioadhesive but until now, it was thought they behaved a bit like some of the synthetic glues – mixing before hardening.  But that still left the question, how does the glue contact the surface in the first place if it is already covered with water?  This is one of the key hurdles to developing glues for underwater applications.

“Advances in imaging techniques, such as 2-photon microscopy, have allowed us to observe the adhesion process and characterise the two components. We now know that these two substances play very different roles – one clearing water from the surface and the other cementing the barnacle down.

“The ocean is a complex mixture of dissolved ions, the pH varies significantly across geographical areas and, obviously, it’s wet.  Yet despite these hostile conditions, barnacle glue is able to withstand the test of time.

“It’s an incredibly clever natural solution to this problem of how to deal with a water barrier on a surface it will change the way we think about developing bio-inspired adhesives that are safe and already optimised to work in conditions similar to those in the human body, as well as marine paints that stop barnacles from sticking.”

Barnacles have two larval stages – the nauplius and the cyprid.  The nauplius, is common to most crustacea and it swims freely once it hatches out of the egg, feeding in the plankton.

The final larval stage, however, is the cyprid, which is unique to barnacles.  It investigates surfaces, selecting one that provides suitable conditions for growth. Once it has decided to attach permanently, the cyprid releases its glue and cements itself to the surface where it will live out the rest of its days.

“The key here is the technology.  With these new tools we are able to study processes in living tissues, as they happen. We can get compositional and molecular information by other methods, but they don’t explain the mechanism.  There’s no substitute for seeing things with your own eyes. ” explains Dr Aldred.

“In the past, the strong lasers used for optically sectioning biological samples have typically killed the samples, but now technology allows us to study life processes exactly as they would happen in nature.”

The press release also notes some possible applications for these research findings (Note: Links have been removed),

Publishing their findings this week in the prestigious academic journal Nature Communications, author Dr Nick Aldred says the findings could pave the way for the development of novel synthetic bioadhesives for use in medical implants and micro-electronics.  The research will also be important in the production of new anti-fouling coatings for ships.

Here’s a link to and a citation for the paper,

Synergistic roles for lipids and proteins in the permanent adhesive of barnacle larvae by Neeraj V. Gohad, Nick Aldred, Christopher M. Hartshorn, Young Jong Lee, Marcus T. Cicerone, Beatriz Orihuela, Anthony S. Clare, Dan Rittschof, & Andrew S. Mount. Nature Communications 5, Article number: 4414 doi:10.1038/ncomms5414 Published 11 July 2014

This paper is behind a paywall although a free preview is available via ReadCube Access.