Just by adding a little light, a new protein-based hydrogel developed by a team of HMS bioengineers can become a substance that mimics many of the properties of elastic tissues such as skin and blood vessels. In addition, the scientists say, finely tuning those properties makes the hydrogel an ideal candidate for use in wound healing. In a paper published online in the July issue of Advanced Functional Materials, scientists in the Biomedical Engineering Division at Brigham and Women’s Hospital describe the hydrogel’s properties as well as the results of its use in preclinical testing.
“So many of the tissues within the human body are elastic,” says Nasim Annabi, an HMS lecturer in medicine at Brigham and Women’s and a co-senior author of the paper. “If we want to use biomaterials to regenerate those tissues, we need a substance with elasticity and flexibility. Our hydrogel is very flexible, can be made from a biocompatible polypeptide, and can be activated using light.”
“Hydrogels are widely used in biomedicine,” says Ali Khademhosseini, an HMS professor of medicine at Brigham and Women’s and a co-senior author, “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.”
The new material, known as a photocrosslinkable elastin-like polypeptide-based (ELP) hydrogel, offers several benefits. When exposed to light, strong bonds form between the molecules in the gel, providing it with mechanical stability.
The scientists report that the 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 lab. The team also found that they could control how much the material swelled as well its strength, finding that the ELP hydrogel could withstand more stretching than that experienced by arterial tissue in the body.
The researchers found that it was possible to combine the gel with silica nanoparticles—microscopic particles previously found to stop bleeding—to develop an even more powerful barrier to promote wound healing.
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