Adv. Mater. http://doi.org/f275ds (2015)

Billions of human pluripotent stem cells will be needed for interventions in regenerative medicine, and also for the screening of pharmaceuticals. A promising way to produce large numbers of stem cells is the use of synthetic, chemically defined polymeric substrates able to offer high cell-growth rates. Yet finding polymers that support the clonal growth of human embryonic stem cells is limited by scaling-up and protein-preconditioning limitations. Now, by using high-throughput screening of polymer microarrays (with over 900 unique polymers), Morgan Alexander and colleagues have found a synthetic copolymer substrate that supports the attachment, pluripotency and expansion of human pluripotent stem cells as well as their direct differentiation into cardiomyocytes, hepatocyte-like cells, and neural progenitors, in commercial media and without the need for protein preconditioning (which is expensive). Also, the researchers identified two key integrins involved in the attachment of the stem cells to the polymer substrate.