Building new living forms, such as xenobots and anthrobots, from unmodified cells to probe what cells can do outside their normal context.
Overview reviewed
Synthetic morphology asks what forms and behaviours cells produce when assembled outside their usual developmental setting. The best-known examples are xenobots: millimetre-scale constructs of frog (Xenopus) skin and heart-muscle cells whose shapes were designed by an evolutionary algorithm and then built by hand (Kriegman et al., PNAS, 2020). A 2021 follow-up showed that some xenobot shapes can gather loose cells into new, motile clusters, which the authors called "kinematic self-replication".
Anthrobots extended the idea to adult human cells. Clusters grown from human tracheal epithelial cells self-assembled into motile, cilia-driven forms and, in a lab dish, promoted neurons to grow over a scratched area (Gumuskaya et al., Advanced Science, 2023).
The terminology ("robots", "self-replication") is debated, and practical applications remain speculative. Most results come from a small number of collaborating labs, and the mechanisms that make these behaviours emerge are largely unknown.
Independent replications, mechanistic studies of how these constructs self-organize, and any demonstration of a reliable, useful function.
Clusters grown from adult human tracheal cells formed motile, cilia-driven constructs, and in a dish, groups of them encouraged neurons to grow across a scratched area.
Some xenobot shapes sweep loose frog stem cells into piles that mature into new motile constructs, a form of replication the authors call kinematic self-replication.
An evolutionary algorithm designed body shapes that were then assembled by hand from frog skin and heart-muscle cells, producing millimetre-scale living machines with behaviours no frog has.