Engineering reversible cell-cell interactions with chemical biology.

Techniques to direct cell-cell interactions have advanced our understanding of fundamental biology and opened new avenues in tissue engineering, regenerative medicine, and immunotherapy. This is often achieved by introducing new targeting ligands to the cell membrane, which can be accomplished through both genetic and nongenetic approaches. While both offer advantages, nongenetic modifications tend to be faster to produce, innocuous to the modified cell, and potentially reversible. This chapter will outline nongenetic methods that have been used to control intercellular interactions-namely hydrophobic insertion, chemical modification, liposome fusion, metabolic engineering, and enzymatic remodeling-and provide protocols that can serve as a starting point for future applications.