The potential ethical challenges in this process of growing organs for their replacement in the human body surely would be related to the nature of how this process is done. Scientists must conduct this by setting low the possible diseases that could arise from these tissues and inhancing their cells to develop faster their regular functions. Then, a possible ethical problem we would face, would be that not all patients would have access to this therapy.
After the passing of time, we would see how almost all the worldwide human population would have all these replaced organs that develop better their functions than normal-non replaced organs. In this scenario, surely health insurance companies would have a preference to give their services only to people with these replaced organs, due to a lower rate of diseases in these patients, than in the one with non-replaced organs.