Bioengineered glands that make tears or saliva can take on the function of their natural counterparts when transplanted into mice.

Takashi Tsuji and his colleagues at the Tokyo University of Science harvested cells destined to form tear and salivary glands from mouse embryos and cultured them for three days in plastic devices that mimic conditions in developing embryos.

The bioengineered glands were implanted in mice from which the natural glands had been removed. The tissue then matured and connected with the animals' nervous systems and ducts for tears and saliva, producing the fluids in response to appropriate stimuli.

Nature Commun. 4, 2497; 2498 (2013)