Researchers at the University of Waterloo have developed a water-rich gel designed to provide temporary support as damaged soft tissue heals. The material, a hydrogel inspired by sea cucumbers’ ability to alter the stiffness of their bodies, was tested in rats with damaged tendons and was associated with improved healing compared with repair using stitches alone.
The work points toward a possible new approach for injuries in which healing tissue needs support but a permanent implant may not be desirable. The gel gradually breaks down and is absorbed by the body, rather than remaining in place indefinitely. A paper describing the work, titled “Bioinspired Hydrogels with Broadly Programmable Mechanics for Soft-Tissue Interfaces,” was published in Advanced Functional Materials.
A scaffold designed for different tissues
Hydrogels are materials with a high water content. In this case, the material is intended to act as a temporary structure around an injury, supporting the growth of new tissue while the material itself degrades. The Waterloo team says its design can be adjusted to make the gel softer or stiffer, a useful property because tissues across the body do not have the same mechanical requirements.
A material used near the brain, for example, would need to behave differently from one placed around a tendon. Project lead Dr. Yimin Wu, a mechanical engineering professor at Waterloo, described that distinction as central to the effort: a single scaffold is not necessarily appropriate for every soft-tissue repair. The programmable mechanics of the hydrogel are intended to let researchers tailor the support to an injury site rather than treating soft tissue as a uniform category.
The biological inspiration comes from sea cucumbers, animals known for changing the stiffness of their bodies. The researchers adapted that broad concept into a synthetic, moist and flexible material for soft-tissue interfaces. The result is not presented as a finished treatment for people, but as a platform that could potentially be developed for tendons and other soft tissues.
Preclinical tendon results
After nearly four years of research, an international team evaluated the gel in a preclinical rat study. Rats with damaged tendons that received the hydrogel showed improved healing relative to animals whose tendons were repaired with stitches alone, according to the researchers.
The team reported that the gel supported the growth of new tissue that was more organized as healing progressed. It also observed improvements in the repaired tendons over the stitches-only comparison group. Those findings are encouraging because tendon repair depends on more than simply reconnecting tissue: the repaired area must regain useful structure while coping with repeated mechanical stress.
The gel degraded over about eight weeks in the reported study. That timed disappearance is an important part of the design. The objective is for the scaffold to assist during the healing period and then be absorbed, reducing the prospect of leaving permanent material at the repair site.
Promise, with a substantial path ahead
The findings remain preclinical. Results in rats do not establish that a material will be safe or effective in people, and the study does not amount to evidence for a clinical treatment. Further work would need to establish how the material performs in additional models, how reliably its mechanical properties can be tuned for particular uses, and whether the degradation process and healing response are appropriate in humans.
Still, the study highlights a design direction for regenerative medicine: temporary materials that combine structural support with the ability to adapt to the mechanics of the tissue being repaired. If that approach translates beyond the initial tendon experiments, it could give clinicians another option between simple suturing and more permanent implanted materials.
For now, the achievement is a preclinical demonstration of a biodegradable scaffold whose properties can be varied and whose use was linked to better-organized tendon healing in the reported animal study. The next question is whether the same combination of temporary support and tunable stiffness can meet the more demanding requirements of human soft-tissue repair.
This article is based on reporting by Phys.org. Read the original article.
Originally published on phys.org
