Injectable biomaterial assists tissue repair

Researchers in Canada have developed a new hydrogel biomaterial that is claimed to structurally support the regrowth of heart, muscle and vocal cord tissue.

The scientists, from McGill University in Montreal, developed the injectable material with a view to aiding the repair of organs and tissues that undergo a high degree of movement or stress. In the past, similar substances have failed to endure the repetitive strain of heartbeats or muscles flexing. The novel hydrogel, however, once injected into the body, forms a stable, porous structure that allows cells to grow and pass through it, helping to repair injured organs.

“People recovering from heart damage often face a long and tricky journey,” said Guangyu Bao, a PhD candidate in the Department of Mechanical Engineering at McGill University. “Healing is challenging because of the constant movement tissues must withstand as the heartbeats. The same is true for vocal cords. Until now there was no injectable material strong enough for the job.

“The results are promising, and we hope that one day the new hydrogel will be used as an implant to restore the voice of people with damaged vocal cords, for example laryngeal cancer survivors.”

The work, reported in the journal Advanced Science , describes how the scientists tested the durability of material using a machine they developed to simulate the extreme biomechanics of human vocal cords. Vibrating at 120 times a second for over six million cycles, the new biomaterial remained intact while other standard hydrogels fractured into pieces, unable to deal with the stress of the load.

“We were incredibly excited to see it worked perfectly in our test,” Guangyu Bao continued. “Before our work, no injectable hydrogels possessed both high porosity and toughness at the same time. To solve this issue, we introduced a pore-forming polymer to our formula.”

The group claims that as well as tissue repair, the innovation could also have applications in drug delivery, tissue engineering, and the creation of model tissues for drug screening. Another avenue of research is using the hydrogel technology to create lungs in order to test COVID-19 drugs.