Before LED light is shined on it, the injected gel is still fluid and can fill up any gaps of spaces under the skin.
What's the News: Scientists have developed a gel that could be used to rebuild the faces of crash victims
. Activated by light, it solves several of the problems inherent in the usual methods. What's the Context:
Dealing with damaged soft tissue is often more complex than dealing with damaged bone and skin. The shape of someone's face is dependent on the fat, muscle, and other tissue below the surface, and doctors trying to restore someone's facial structure must contend with scar tissue, swelling, and loss of movement.
Current methods include injecting hyaluronic acid (HA), a naturally occurring molecule that helps thicken the gel that surrounds cells in the body, or synthetic materials, but both of these have their issues: HA injections don't last, and synthetic materials can cause inflammation. Grafting soft tissue from other parts of the body is also an option, but that can cause scar tissue to form where it was removed and at the graft site.
Additionally, it's not possible to control the shape of the synthetic materials after they're put in the body, nor can the HA be made to conform to a certain shape.
How the Heck:
The new substance is made of HA mixed with an FDA-approved plastic, polyethylene glycol, or PEG. Experimenting in rats, the researchers found that just the right mixture of the two alleviates the problems experienced by solely synthetic or solely biological implants or grafts. More than a year after the rats received the implants, they had maintained their shape.
Importantly, the material can be molded and set once it's inside the body. First, it's injected into the desired area, then massaged into the right shape. When it's in the right configuration, shining an LED light over the skin causes the molecules to crosslink and firm up.
The team also tried the substance on several human volunteers who were having tummy tucks and found that it held up well for 12 weeks after surgery.
The Future Holds: Future research will investigate more specifically how the gel will work in humans---the researchers noticed more inflammation than they expected in their volunteers, so sussing out how it interacts with the human immune system is next on the agenda. Reference: Hillel et al. Photoactivated Composite Biomaterial for Soft Tissue Restoration in Rodents and in Humans. Sci Transl Med 27 July 2011: Vol. 3, Issue 93, p. 93ra67 DOI: 10.1126/scitranslmed.3002331
Image credit: Hillel et al. Science Trans Med