On Star Trek: The Next Generation, Commander Riker had an impressive ability to receive head wounds. Luckily for him, Dr. Crusher could whip out the “dermal regenerator,” a handheld sci-fi tool that healed skin wounds with a colorful laser.
Luckily for us, Kaushal Rege and colleagues at Arizona State University are developing essentially the same thing. Well, close enough. In a new paper out from the journal Advanced Functional Materials, the engineers successfully repaired animal wounds with a silk and gold nanomaterial activated by a laser.
In this proof-of-concept study, the technology quickly sealed soft-tissue wounds in pig intestines and on mice skin. In the pig intestines, for example, the seal proved to be roughly seven times as strong as traditional sutures.
When sealing wounds, sutures, staples, or glue can often cause problems such as leakages at the repair site and slow recovery of the tissue. “We’re trying to seal incisions faster and heal them at an earlier point of time,” says Deepanjan Ghosh, a Ph.D. student in Rege’s lab and coauthor on the paper.
To use a laser to seal skin, one must focus the heat of the light using some sort of photoconverter. Rege’s lab opted for gold nanorods and embedded them in a silk protein matrix purified from silkworm cocoons. A silk protein called fibroin binds to collagen, the structural protein that holds together human skin cells. When near-infrared light hits the gold nanorods, they produce heat and activate the silk and skin to create bonds, forming a sturdy seal.
The near-infrared laser operates at a wavelength of about 800 nanometers, which is powerful enough to heat the gold without damaging the skin.
The engineers created two disk-shaped sealants: one for wet environments that does not dissolve in water and one for dry environments that does. The first was used to repair samples of pig intestine. When the team pumped colored liquid through pieces of repaired intestine, the laser-activated sealant was seven times better than traditional sutures or glue at preventing liquid from escaping. In fact, the laser-repaired intestines performed just as well as normal, undamaged intestines, according to Ghosh.
Next, the group tested the water-dissolving sealant on mouse skin. When applied in a paste to a one-centimeter incision in the skin, the team’s treatment resulted in significantly higher skin strength two days after surgery compared with stitches or skin glue. Plus, it was fast—spending only about 4 minutes under the laser.
Because near-infrared light can penetrate fairly deeply into tissue, Ghosh and colleagues hope to use the technology to eventually repair things like blood vessels and nerves—tissues that are often deep in the body and time-consuming to repair. “Suturing takes a lot of effort given the dimensions of a nerve or a blood vessel, even for fully trained surgeons,” says Ghosh.
Ghosh expects the cost of the silk-gold material will not be prohibitively expensive, and the lasers would be a one-time equipment cost for medical centers.
They are currently watching how the laser-activated seals hold up in living rats. If that goes well, they’ll move to pigs, and perhaps eventually, humans.
Dr. Crusher would be so proud.