3D printing used to control stem cell differentiation

The time between conception and becoming a fetus is a busy one if you're a human embryonic stem cell (hESC). As the embryo develops, hESCs are allocated into three distinct types of tissue through an orderly sequence of events. Although it's easy to grow hESCs in a culture dish, it's been impossible to make them repeat this orderly process—until now.

Scientists from the Laboratory of Stem Cell Biology and Molecular Embryology at Rockefeller University are using principles from geometry to control the patterns through which hESCs develop.

The scientists tested how stem cell identity is affected by an array of geometries by creating molds made of Polydimethylsiloxane (PDMS), a silicone-based elastomer. The group controlled the diameters and depth of the molds by 3D printing them. To get the hESCs to stick to the printed material, the scientists coated the molds with proteins that were known to increase cell adhesion. Once the molds were ready, the cells were added and allowed to incubate.