Tissue Engineering is a multidisciplinary scientific field working on the development of lab grown tissues, such as organs, muscle tissues, or specific cell types, by combining expertise from synthetic biology, molecular biology, biology, chemistry, material science, and mathematics.
The SynNotch system developed by Dr. Wendell LimWendell Lim's lab at UC San Francisco and patented to Cell Design Labs, is also being used for the generation of self-organizing tissue. Lim’s lab used synNotch to program two groups of cells to self-organize into a two-layered sphere. One group of cells expressed a signaling protein on their surfaces and the second group were engineered with a custom synNotch receptor programmed to detect the protein on the surface of the other cells. Neither of the cell types formed structures on their own but when grown together, the first cells activated the other cells to produce cadherin proteins, making them sticky and cluster together. The sticky cells formed a core and the other cells formed the outer layer. In the paper published in Science in 2018, Lim’s group demonstrated self-assembly of multiple tissue patterns and the ability of their spheroids to self-repair when damaged.
A method for construction of self-assembling structures would use the sequence, 1) form a pattern, 2) change gene expression, 3) trigger morphogenesis. Researchers from University of Edinburgh described their construction of a net-like structure by two cell typescell types which formed a pattern, resulting in differential gene expression between the two cell types. The holes in the “net” were formed when a morphogenic effector was used to drive cell death in one cell type.