The work provides a new approach to prodding stem cells to grow into different tissues. Before, researchers created a variety of cell types from one batch of stem cells, then isolated the cell type of interest. The isolated cells were then grown on a given medium, such as a polymer scaffold. The same MIT team did just that last year with the endothelial cells that blood vessels are composed of.
This time around, the MIT researchers seeded stem cells directly into the scaffold. "We found that with different growth factors, we could push them in different directions," said Levenberg.
The polymer scaffold is key. "The scaffold provides physical cues for cell orientation and spreading, and pores provide space for remodeling of tissue structures," the researchers wrote.
The scaffold was carefully engineered. "If the scaffold is too soft," for example, "it collapses under the cells' mechanical forces," said Levenberg. The team also used two different polymers to create the scaffold. "One degrades quickly, the other more slowly," she said. "That gives cells room to grow while still retaining a support structure for them."
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Contact: Elizabeth A. Thomson
thomson@mit.edu
617-258-5402
Massachusetts Institute of Technology
13-Oct-2003