"Since DNA has essentially an unlimited capacity for information storage, there is no theoretical limit on the number of different cell types we can assemble in a structure," says Bertozzi. The key is to give each cell type its own unique DNA "bar code," enabling its programmed interaction with any other specified cell type. "In practice, I think structures with three or four cell types are quite feasible. Such structures would be relevant to many biological organs."
Structured microtissues have numerous research applications, says Bertozzi, particularly "in probing how the local cellular environment affects the behavior of a particular cell. Also, we can study how systems of cells work together to produce complex organ functions. Examples include how T cells and B cells work together in the lymph nodes to mount an immune response against foreign antigens."
Practical challenges remain, such as scaling up the production of tailored microtissues to quantities needed for biomedical applications. Beyond that, Bertozzi hopes to refine the present method of modifying cell-surface DNA.
"As it stands, the need for unnatural sugar biosynthesis limits the kinds of cells that we can use in microtissue construction," she says. "There are other ways in which DNA can be conjugated to cells, independent of their sugar metabolic pathways, and we intend to explore those avenues."
|Contact: Paul Preuss|
DOE/Lawrence Berkeley National Laboratory