A team of bioengineers at Brigham and Women’s Hospital (MA, USA) have developed a new protein-based gel that, when exposed to light, mimics many of the properties of elastic tissue, such as skin and blood vessels
The Brigham and Women’s Hospital’s (MA, USA) research team reports on the key properties, many of which can be finely tuned, of a new protein-based gel capable of mimicking elastic tissue, and discuss the results of using the material in preclinical models of wound healing. The findings were recently published in Advanced Functional Materials.
“We are very interested in engineering strong, elastic materials from proteins because so many of the tissues within the human body are elastic. If we want to use biomaterials to regenerate those tissues, we need elasticity and flexibility,” explained Nasim Annabi, a co-senior author of the study and member of the Biomedical
Engineering Division. “Our hydrogel is very flexible, made from a biocompatible polypeptide and can be activated using light.”
“Hydrogels — jelly-like materials that can mimic the properties of human tissue — are widely used in biomedicine, but currently available materials have limitations. 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,” continued one of the study leaders Ali Khademhosseini, also a member of the Biomedical
The new material, known as a photocrosslinkable elastin-like polypeptide-based hydrogel (ELP), offers a number of benefits. The elastic hydrogel is formed by using a light-activated polypeptide. When exposed to light, strong bonds form between the molecules of the gel, providing mechanical stability without the need for any chemical modifiers to be added to the material.
The team reports that ELP hydrogel can be digested over time by naturally occurring enzymes and does not appear to have toxic effects when tested with living cells in the laboratory. The team also discovered that the ELP hydrogel could withstand more stretching than experienced by arterial tissue in the body.
“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,” stated 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 also demonstrated that it was possible to combine the ELP gel with silica nanoparticles — microscopic particles previously found to stop bleeding — with the potential to develop an even more powerful barrier to promote wound healing.
“This could allow us to immediately stop bleeding with one treatment,” concluded 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.”
Sources: Zhang YN, Reginald AK, Queralt VM et al. A highly elastic and rapidly crosslinkable elastin-like polypeptide-based hydrogel for biomedical applications. Adv. Funct. Mater. doi:10.1002/adfm.201501489 (2015) [Epub ahead of print]; Brigham and Women’s Hospital press release: http://www.brighamandwomens.org/about_bwh/publicaffairs/news/PressReleases/PressRelease.aspx?sub=0&PageID=2101