It definitely shouldn't work across species, but that's the least of Bruce's scientific aggravations in Keeliai.

He drags his eyes away from the oculars and gives Jim a more considering, level look. "Theoretically, maybe. What do you want it for?" So sue him for being leery of replicating an insanely powerful, cross-species regenerative for someone from the military. Bruce likes Jim, maybe even trusts him a little, but some suspicions are deeply ingrained in him for a reason.