Can Human Organs Be Cloned?
May human body parts or materials be cloned morally for prosthetics, transfusions, or other medical procedures?
Cloning that does not involve the destruction of human embryos or the creating of a human life is an acceptable scientific procedure if done with legitimate intentions.
If we were able to clone someone's failing organ using a process that did not create another human life nor destroy one, then such a medical procedure would be licit. The same would be true with a leg, arm, hand, etc.
Document of the Holy See on Human Cloning
Prospects for Xenotransplantation Scientific Aspects and Ethical Considerations