Inspired by the remarkable ability of sea cucumbers to change the stiffness of their bodies, University of Waterloo researchers have developed a gel that could one day help repair damaged tendons and other soft tissues without leaving permanent material behind.
The water-rich material, known as a hydrogel, acts as a temporary support structure that allows new tissue to grow as the material gradually breaks down. Like the sea cucumbers that inspired it, the gel can be made softer or stiffer, potentially allowing it to support the healing of different tissues throughout the body.
“Soft tissues don’t all require the same scaffold,” said Dr. Yimin Wu, a mechanical engineering professor at the University of Waterloo, which spearheaded the study. “A material placed near the soft brain must behave differently than one used to repair a hard tendon.”
After nearly four years of research, the international team tested the gel in a preclinical study involving rats, with promising results. Rats with damaged tendons treated with the gel showed improved healing compared with those repaired with stitches alone.
The results showed that the gel helped support the growth of new, more organized tissue. As the tendons healed, the gel gradually broke down and was absorbed by the body over approximately eight weeks.
The researchers also observed improvements in the repaired tendons compared with those treated using stitches alone, suggesting the material could help support more effective healing.
“We were extremely encouraged by the results,” said Dr. Youchao Teng, who led the project under Wu’s supervision. “The material did more than perform well. The tendon was regenerated with more organized new tissue and comparable function to a healthy tendon.”
To create the gel, researchers first freeze the material to form its internal structure. They then soak it in specially prepared salt solutions that allow them to adjust its stiffness, making it softer or firmer depending on the tissue it is designed to support.
This ability to customize the gel could eventually make it useful for repairing a range of tissues, including muscles, cartilage, skin and even delicate tissues in the brain and other organs. However, further research is needed to determine whether it can safely and effectively support healing in these different parts of the body.
Wu and Teng have applied for two patents related to their work and formed a company to try to commercialize it. Next steps include testing on larger animals and, eventually, clinical trials.
The project involved close collaboration with Dr. Song Li at the University of California, Los Angeles (UCLA) and Dr. Badri Narayanan at the University of Louisville.
The research team also included Waterloo engineering professors Dr. Zhao Pan and Michael K.C. Tham, as well as members at facilities and additional universities in the United States, Taiwan, China and Canada.
A paper on the study, Bioinspired Hydrogels with Broadly Programmable Mechanics for Soft-Tissue Interfaces , was recently published by the journal Advanced Functional Materials .
Advanced Functional Materials