Highly adhesive hydrogel sticks to the task of tissue regeneration
Researchers from all corners of medical science are hoping to harness advanced hydrogels to help repair damaged hearts, regrow brain tissues, or quickly shut down bleeding wounds, to name just a few examples. Scientists in Switzerland have now developed a new form of the material they say has unparalleled adhesive properties, a characteristic that could prove particularly useful in trying to repair cartilage and meniscus.
Unlike some other tissues in the human body, cartilage and meniscus have a negligible supply of blood, or none at all, and therefore won't regenerate on their own once damaged. Scientists have already looked to offer a helping hand by injecting hydrogels packed with different drugs into the damaged areas, but these tend to wash away due to the natural machinations of the human body and the flow of its fluids.
In a new study, scientists at Switzerland's École Polytechnique Fédérale de Lausanne describe a new kind of material they think can stick to the task. Their hydrogel is almost 90 percent water and includes of a web of cross-linked polyethylene glycol dimethacrylate together with cross-linked alginate, reinforced with nanofibrillated cellulose.
The resulting structure is claimed to be 10 times more adhesive than commercially available bioadhesives, and due to its high water content, bears a strong similarity to the natural tissues it is supposed to heal. But most importantly, it remains highly adhesive over time because the uniquely layered material absorbs the mechanical stresses that would otherwise wash it away.
"The double network structure distributes incoming mechanical energy throughout the hydrogel, so that the material shows adhesion improvement when it is compressed or stretched," says Dominique Pioletti, leader of the research. "In hydrogels that lack these damping mechanisms, the mechanical stresses are concentrated on the interface between the hydrogel and the tissue, and the hydrogel comes off quite easily."
As it stands, the team has adhered the hydrogel to several types of natural tissues like cartilage and meniscus in the lab and are pretty enthused about the possibilities. They say with further work it could be used for things like replacing the titanium plates implanted to set bone fractures, and in the shorter term, eliminate the need for sutures to seal up wounds.
"Now that our material has demonstrated its superior mechanical properties, we are going to work on loading it with different agents that could help heal a patient's cartilage or meniscus," says Pioletti.
The team has published its research in the journal Applied Materials & Interfaces, while you can hear them describe the work in the video below.