Where the wild molecules are: Engineering the spatial distribution of signaling molecules

The spatial distribution of the signaling molecules that mediate cell–cell communication and pattern formation is an important consideration for natural and engineered multicellular systems.

Signaling molecule concentration profiles directly impact cell response profiles, and various experimental techniques can be utilized to modulate these spatial distributions. Current strategies focused on physically or chemically modifying the extracellular space to affect signal distribution include performing experiments in microfluidic devices with dynamic user-controlled inputs and flow rates or adjusting the mesh sizes and protein binding affinities of extracellular matrix-mimicking hydrogels. Recent advances in synthetic biology have paved the way for new approaches that involve directly engineering the signaling molecules, their interactors, and their downstream effectors for fully orthogonal communication platforms.