LIGHT-ACTIVATED ELASTIC HYDROGEL MIMICS HUMAN TISSUE

Elastin-like polypeptide-based (ELP) Hydrogel From Brigham and Women’s Hospital

Bioengineers at Brigham and Women’s Hospital in Boston have developed a new protein-based gel that imitates many of the elastic properties of human tissue. Aiming for a strong, flexible substance to aid tissue regeneration, the team, led by Ali Khademhosseini, PhD, and Nasim Annabi, PhD, of the Biomedical Engineering Division, used a light-activated biocompatible polypeptide to create the hydrogel. According to Khademhosseini, many hydrogels currently used in biomedicine are synthetic and degrade into toxic chemicals over time, while some natural gels are not strong enough to withstand the flow of arterial blood. The new material, known as a photocrosslinkable elastin-like polypeptide-based (ELP) hydrogel, is comprised of molecules that form strong bonds when exposed to light. This property gives the hydrogel the mechanical stability to support such conditions as blood flow without the addition of chemical modifiers.

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,” said Annabi. “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.” The team’s findings indicate that ELP hydrogel can be digested overtime by naturally-occurring enzymes and has no toxic effects when tested with living cells in the lab. They were also able to control the material’s strength and how much it swelled, which helped to determine its ability to withstand more stretching than that experienced by arterial tissue in the body. Mixing the gel with silica nanoparticles allowed it to more effectively prevent bleeding and better protect wounds. The material’s properties and safety will require further testing in pre-clinical models, however, before it can be approved for human use.