Stem cell-loaded microneedles speed up wound healing

Stem cells are powerful tools that could one day unlock new frontiers in regenerative medicine. Now, a new study has shown that a certain type of stem cell can be delivered into injured tissues with dissolvable microneedles, to heal wounds.

Mesenchymal stem cells (MSCs) are responsible for replenishing bone, cartilage, muscle and fat cells in the body. But more recently, scientists have found that they have broader healing potential. If introduced to injured tissue, MSCs have been found to boost the formation of new blood vessels, reduce inflammation, and keep cells alive.

But there are a few problems. For one, injecting MSCs into the tissue with regular needles can cause further damage and scarring. Plus, it takes huge amounts of the cells to make sure that enough of them stick around to do their job.

So for the new study, researchers at the Terasaki Institute and the University of California Los Angeles (UCLA) set out to find a less invasive, more effective way to deliver MSCs. Rather than introduce them in bulk, the team wanted to find a way to keep MSCs healthy, so that they could stay there and function for longer.

In this case, the researchers made microneedles out of the gelatin matrix, complete with MSCs. These were then encased in a shell made of a tougher biomaterial called PLGA. Once embedded in a wound, the PLGA dissolves first, and as it does the microneedles begin to poke out between the cracks, allowing them to deliver their payloads. In lab tests, 90 percent of the MSCs were still alive and functioning 24 hours later.