Brain repair: These three images show the new tissue, in black, growing to fill the stroke-induced cavity in the brain (left to right) a) before the introduction of the particles containing stem cells, b) one day after their introduction, and c) seven days after.
“This project is an excellent example where, by understanding the importance of biomaterial scaffolds, the cells are better able to populate the void left by the injury,” says Jonathan Cooper, a bioengineer at the University of Glasgow. “Not only does the biomaterial act as a support for the cells when they are seeded into the void, but as the scaffold is degraded, it provides the physical space for new blood vessels to form.”
The key to the advance was the ability of the new polymer to encourage the growth and differentiation of the neural stem cells at three different scales, says Modo’s colleague Kevin Shakesheff, a tissue engineer at Nottingham University. “At the large scale, it enables the void formed by the injury to get new blood vessels very quickly, which is vital if the new tissue is to survive. At the cellular level, the scaffold surface allows stem-cell receptors to attach to it. And at the molecular level, it will allow cells to mix with the right growth factors.”
Shakesheff says that extensive testing is needed before human trials of the matrix can begin. He hopes, however, that the PLGA polymer will be marketed within 12 months for use in bone surgery.