Bioinspired, sponge-like shrinking gel steers tooth, tissue formation

A bit of pressure from a new shrinking, sponge-like gel is all it takes to turn transplanted unspecialized cells into cells that lay down minerals and begin to form teeth.

The bioinspired gel material could one day help repair or replace damaged organs, such as teeth and bone, and possibly other organs as well, scientists from the Wyss Institute for Biologically Inspired Engineering at Harvard University, and others report recently in Advanced Materials.

"Tissue engineers have long raised the idea of using synthetic materials to mimic the inductive power of the embryo," said Don Ingber, M.D., Ph.D., Founding Director of the Wyss Institute, Judah Folkman Professor of Vascular Biology at Harvard Medical School, Professor of Bioengineering at SEAS, and senior author of the study. "We're excited about this work because it shows that it really is possible."

Embryonic tissues have the power to drive cells and tissues to specialize and form organs. To do that, they employ biomolecules called growth factors to stimulate growth; gene-activating chemicals that cause the cells to specialize, and mechanical forces that modulate cell responses to these other factors.

But so far tissue engineers who want to build organs in the laboratory have employed only two of the three strategies -- growth factors and gene-activating chemicals. Perhaps as a result, they have not yet succeeded in producing complex three-dimensional tissues.