There are several competing lines of technology: 1) humanized organs in animals such as pigs. 2) decellularization of animal organs, such as from pigs, follow

There are several competing lines of technology: 1) humanized organs in animals such as pigs. 2) decellularization of animal organs, such as from pigs, followed by replacement with the patient's cells. 3) outright creation of organs from scratch, from a patient's cells (e.g. https://www.neworgan.org https://www.neworgan.org ) 4) repair of existing organs in situ. It will be interesting to see how it shakes out; #1 and #2 are only in the running instead of #3 because no-one yet has a good solution for creating the blood vessel networks needed for full size tissue engineering. At the moment only organoids or other thin tissues (e.g. trachea, esophageal lining) can be constructed reliably. #3 is only a goal to the extent that #4 isn't figured out: how to spur regeneration and change cell behavior for the tissues that exist.