A hydrogel developed by the BWH Biomedical Engineering Division team is strong, flexible, and biocompatible.
Brigham and Women’s Hospital (BWH) bioengineers have a developed a unique hydrogel whose properties could provide significant benefits in wound healing. The BWH Biomedical Engineering Division team, led by biomedical engineer Ali Khademhosseini, PhD, MASc, and chemical engineer Nasim Annabi, PhD, reported their findings in the July 1, 2015, online edition of Advanced Functional Materials.
“Hydrogels are widely used in biomedicine, but currently available materials have limitations,” says Khademhosseini, study senior author and Director of the BWH Biomaterials Innovation Research Center. “Some synthetic gels degrade into toxic chemicals over time, and some natural gels are not strong enough to withstand the flow of arterial blood through them.”
Preclinical testing by the BWH Biomedical Engineering Division team, however, shows that their hydrogel is strong, flexible, and biocompatible (harmless to living tissue).
Like other hydrogels, the new gel – known as a photocrosslinkable elastin-like polypeptide-based (ELP) hydrogel – is swollen through exposure to water. The water content gives the material its jelly-like flexibility, mimicking the elastic properties of human tissue, such as skin and blood vessels.
The gel’s polypeptide (protein) content, on the other hand, adds strength. When the gel is exposed to ultraviolet light, strong bonds form between the protein molecules. This gives the gel stability without using potentially toxic chemical agents.
After this strong and flexible gel has served its role in healing, naturally occurring enzymes are able to gradually and thoroughly break down (digest) the gel with no toxic effects. As the gel breaks down, natural, healthy tissue moves into its place.
Although the researchers have been focusing on the gel’s potential as an aid in wound healing, they believe that it could serve many other purposes.
“Our hydrogel has many applications: it could be used as a scaffold to grow cells or it can be incorporated with cells in a dish and then injected to stimulate tissue growth,” says Annabi, study co-author. “In addition, the material can be used as a sealant, sticking to the tissue at the site of injury and creating a barrier over a wound.”
Researchers discovered that they can tweak the gel’s properties to control the material’s swelling or strength, and they’re exploring other modifications to suit particular applications. They could, for instance, combine the gel with silica nanoparticles, microscopic particles that have shown success in stopping bleeding.
“This could allow us to immediately stop bleeding with one treatment,” says Annabi. “We see great potential for use in the clinic. Our method is simple, the material is biocompatible, and we hope to see it solve clinical problems in the future.”The BWH Biomedical Engineering Division team will continue pre-clinical testing of the hydrogel’s effectiveness and safety before the material is approved for use in humans. - Chris P.