New material could support stem cell development

The right kind of support could make stem cells more biddable.

A new gel may give physical cues that coax stem cells to develop correctly and repair tissue damaged by heart attacks. The gel mimics the way heart tissue stiffens throughout development, researchers from the University of California, San Diego, reported in San Diego December 8 at the annual meeting of the American Society for Cell Biology.

Previous work by the group, led by Adam Engler, showed that stem cells can respond to mechanical cues as well as to chemical signals in deciding their fates. Stem cells grown on soft material form into soft tissues such as brain, and those grown on hard materials form bonelike tissues.

After a heart attack, the heart muscle forms a hard scar, which interferes with beating. The scar also makes a hard platform and stem cells injected into the area end up forming bonelike tissue. Researchers hope that stem cells encased in a gel would take cues from the gel and become heart muscles instead of hard, nonmoving tissue.

Jennifer Young, a researcher in Engler’s lab, measured the stiffness of chicken hearts at various stages of development. Young developed a gel that mimics the stiffening pattern of the natural tissue. Embryonic heart cells grown in the stiffening gel make more of a heart cell marker compared with cells grown on gels that don’t change stiffness. The researchers haven’t yet grown embryonic stem cells on the gel.