Modern Frankenstein?

For thousands of years, humans have imagined part-animal, part-human beings and endowed them with mystical qualities — think about the Sphinx, the centaur, the mermaid. Now, the idea of animal-human hybrids is no longer purely theoretical: It has entered the world of medicine, where scientists and doctors are starting to be able to use genetically modified animal organs in place of failing human organs to extend human lives. In the not-too-distant future, it may be possible to use animal organs to fully replace human organs and save human lives. 

The emerging field of xenotransplantation (ZEE-no-trans-plant-A-shun) uses organs from animals, especially pigs, to replace those of humans organs. Why pigs? As Bioethics Scholars Olivia Zhang ’26 and Ava Builione ’26 explained two years ago, during their Symposium presentation, pig organs are similar in size and function to those of humans, and pigs can be raised in controlled environments. Using tools such as CRISPR, scientists can strategically edit pig genes so that their organs will be more likely to be accepted by the human immune system.  

One of the first xenotransplantation procedures was performed for Lisa Pisano of Cookstown, New Jersey. Ms. Pisano was in both heart and kidney failure when she received a novel combination of treatments — an implantable heart pump and a pig kidney. Ms. Pisano, who was the first woman to receive a pig kidney, survived with it for 47 days before it was removed because of damage caused by the medications she was taking for heart failure. Ms. Pisano died from her illnesses several months after the historic surgical procedure, but her experience provided scientists and doctors much valuable knowledge.  

Developments in the science of pig kidney transplantation offered new possibilities for patients on the list. According to the United Network for Organ Sharing (UNOS), at any given time in the United States, some 90,000 people are waiting for a kidney transplant, and 11 people die every day while waiting for a kidney.  

In 2024, a team of surgeons in China transplanted a genetically modified pig liver into a human patient suffering from liver failure. The pig liver underwent ten genetic edits to make it more compatible with the human body, and it worked alongside the patient’s own liver for 38 days, producing bile, helping with blood clotting, and supporting metabolism. Although the pig liver was eventually removed because of complications, the patient’s own liver continued functioning — suggesting that animal organs might serve as temporary bridges to recovery as well as long-term or permanent transplants.,,,

Xenotransplantation offers hope but at the same time it raises important bioethical concerns. Some of the issues we need to consider:  

Animal rights and welfare. Is it ethical to breed and genetically modify animals specifically to serve as sources of organs for ailing humans? If so, what responsibility do we have to ensure that these animals are treated humanely? What standards should guide their care?

Disease risk and safety. Pigs carry viruses that could, in theory, infect humans. In addition, we don’t have long-term safety data on xenotransplantation. In fact, some might say that these early xenotransplantation procedures are experiments. 

Human identity. Would having a pig organ in your body affect your sense of who you are? What impact might it have on thinking about what it means to be “human”?  

Justice and access. If pig kidney and pig liver transplants become more common, who will have access to them? Will these procedures be affordable and equitably distributed? Would it become more difficult to access human organs for transplant? If so, what implications might that have for people who need an organ transplant but whose religion or faith traditions would prohibit an animal–human transplant?  

As we move from myth to medicine, the human-animal frontier is no longer imaginary. It's real, and it's here. The rapidly advancing science of xenotransplantation makes it imperative that we think now about the value of life, about our relationships with animals, and about how to advance technology in an ethical and responsible manner.  

What do you think is the most pressing ethical issue related to xenotransplantation — and how would you address it?  

1 “New Jersey Woman Becomes Second Patient Ever to Receive Pig Kidney in ‘Transformative’ Surgery”

2 “NJ Woman Who Got a Pig Kidney Transplant Plus a Heart Pump Has Died”

3 UNOS, “90,000 People Are Waiting for a Kidney”

4 “Surgeons in China Perform First Pig Liver Transplant in Human Patient”

5 “Chinese scientists achieve world’s 1st successful living pig-to-human liver transplant”

6 “Pig Liver: A Breakthrough in Organ Transplantation”

7 “Engineered Pig Organs for Human Transplant”