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Human embryonic stem cells are coaxed to differentiate into skin cells on top of two spots of biomaterial. The marker for the skin cells is stained green and cell nuclei are blue. |
Scientists already identified a simple method for producing pure populations of epithelial-like cells from hES, which could be used to make synthetic skin. These cells carry the potential to differentiate into specialized cells, but making them do so is not easy. One factor is the material the cells grow on outside the body, which is the focus of the MIT research.
The new technique is fast and lets scientists test hundreds to thousands of different materials simultaneously. The trick is that the process is miniaturized, according to Daniel G. Anderson, research associate in the Dept. of Chemical Engineering. The team developed robotic technology to deposit over 1,700 spots of biomaterial on a glass slide measuring 253 75-mm long. Twenty slides, or microarrays, can be made in one day. Exposure to ultraviolet light polymerizes the biomaterials, making each spot rigid and ready for “seeding” with hES or other cells. Another feature is that the microarrays work with a minimal number of cells, growth factors, and other media. “That's especially important for human embryonic stem cells because the cells are hard to grow, and the media necessary for their growth are expensive,” says Anderson. Also, many of the media related to testing the cells, such as antibodies, are expensive. Scientists used an initial screening to find promising biomaterials for the differentiation of hES into epithelial cells. Additional experiments identified a host of unexpected materials effects that provide new levels of control over hES cell behavior, showing the effects of quick, easy screenings.