Bioengineers: Matrix stiffness is an essential tool in stem cell differentiation

Bioengineers at the University of California, San Diego have proven that when it comes to guiding stem cells into a specific cell type, the stiffness of the extracellular matrix used to culture them really does matter. When placed in a dish of a very stiff material, or hydrogel, most stem cells become bone-like cells. By comparison, soft materials tend to steer stem cells into soft tissues such as neurons and fat cells. The research team, led by bioengineering professor Adam Engler, also found that a protein binding the stem cell to the hydrogel is not a factor in the differentiation of the stem cell as previously suggested. The protein layer is merely an adhesive, the team reported Aug. 10 in the advance online edition of the journal Nature Materials.