Stem cells are often touted for their ability to differentiate into other tissues. These immature cells can be coaxed into becoming neurons, heart muscle cells or pretty much anything else. But that’s not their full repertoire. Stem cells also secrete proteins and other molecules that can help other cells grow. Even better, these growth factors can act as a tonic for sick or dying cells, helping them survive.

That’s the idea behind Eduardo Silva’s work. An assistant professor of Biomedical Engineering, Silva has spent years working out how to isolate these growth factors and deliver them where they can provide the most benefit. Now he has patented a therapeutic biogel that can promote wound healing. The idea is quite simple, but the details have taken years to work out.

One of the most helpful factors is a protein called VEGF, which stimulates blood vessel growth. Creating new blood vessels means bringing more nutrients, oxygen and other factors to the injury site.

“VEGF is a potent survival factor,” says Silva. “Cells react well to it.”

In addition to VEGF, Silva’s lab isolated other helpful factors to encourage wound healing, but that’s just part A. Part B was finding an effective way to deliver the medicine so it would remain at the wound site.

Silva found his solution in alginates, which are extracts from brown algae. Though the material sounds exotic, it’s actually quite commonplace.

A common substance

“I often joke that if you’ve ever had beer or ice cream, you’ve almost certainly ingested alginates,” says Silva.

Alginates form a polymer, a chain of molecules that make an excellent scaffold to attach therapeutic agents, such as growth factors. Silva used alginates to create a therapeutic gel that’s 2 percent polymer and 98 percent water.

The gel provides a number of wound-healing benefits. First, it applies the factors where they are most needed. From there, the proteins apply their own healing magic, as well as recruit other beneficial cells to the wound site. The gel also controls how rapidly the factors are released. In addition, because the gel is mostly water, it further promotes healing by preventing the wounded area from drying out. The gel could be placed directly on a wound, injected or incorporated into bandages.

Application for burns

The recently patented gel could be especially useful for diabetics, whose wounds are notoriously difficult to heal. The technology is also generating interest from clinicians at the UC Davis Firefighters Burn Institute Regional Burn Center.

When treating burns, surgeons often graft healthy tissue from other parts of the patient’s bodies, but this approach has some serious limitations.

“Patients with massive burns have limited skin to cover them,” says chief of Burn Surgery David Greenhalgh.

“Most of the time, we have to take the skin they have, wait for it to re-heal and then harvest it again, which can take months.”

For Greenhalgh and colleagues the biogel could offer the next best thing to artificial skin – a method to more rapidly heal a patient’s skin so it can be re-harvested.

The biogel has proven successful in early studies, but there’s a long way to go before it can be used in patients. Still, this therapy shows great promise for those suffering from severe wounds.

“The problem has always been finding a way to control how these factors are released,” says Silva. “Now that we’ve solved that, we have the potential to really help wound patients.”