January 7th, 2022 marked a memorable day in the history of medicine because a pig heart was transplanted into a human body for the very first time. This surgery took place at the University of Maryland Medicine, Baltimore, USA. The recipient of the pig heart was a 57-year-old man David Bennett, who could have faced death if he had waited for a human donor. “It was either die or do this transplant,” Mr. Bennett explained a day before the surgery.
As this story broke out, many people wondered how could a pig heart function in a human body without alerting the body’s immune system. This is because the pig from which the heart was taken was genetically modified. That means the molecule(s) in the pig that triggers the human immune system were removed by using the CRISPR–Cas9 genome editing technology which received the 2020 Nobel Prize in Chemistry and was awarded to Emmanuelle Charpentier and Jennifer Doudna.
This story, however exciting it may be, sheds light on the critical situation of organ donation. According to the Indian government database, “An estimated 1.8 lakh people suffer from renal failure every year, however, the number of renal transplants done is around 6000 only. An estimated 2 lakh patients die of liver failure or liver cancer annually in India, about 10-15% of which can be saved with a timely liver transplant. Hence about 25-30 thousand liver transplants are needed annually in India but only about one thousand five hundred are being performed. Similarly, about 50,000 persons suffer from heart failures annually but only about 10 to 15 heart transplants are performed every year in India.”
The data here signifies the large gap between organ donors and recipients. Thus, this surgery is a turning point and gives hope to the people on that waiting list. It will lead to more and more researchers focusing on various alternatives than human donors. One such avenue is xenotransplantation which means transplanting animal organs into humans, but this has its own limitations. For instance, research on xenotransplantation is often conducted on non-human primates such as baboons, but baboons do not serve as a good predictive model because their immune system is more robust than humans. Moreover, researchers will have to study the physiology of animal organs and make sure they function at a similar rate in humans. Furthermore, the biggest drawback is that this whole process is not economically feasible and requires huge capital.
But hold on, there is another exciting field that could address all the limitations of xenotransplantation – 3D Bioprinting of human organs. Imagine a situation where doctors and researchers took some cells from Mr. Bennet’s body and constructed an identical, but brand new heart which can now replace his old heart! In this way, there would not be a rejection from the immune system and there is no need to worry about the physiology as well. This is the potential of 3D Bioprinting of human organs. This field of regenerative medicine could also possibly address the wide gap in organ donation. 3D Bioprinting is still at a naïve stage of its development, however, researchers around the globe are working relentlessly to build this futuristic tool that could revolutionize the field of medicine in the next coming decades.
Excitingly, researchers at Nanomedicine Research Group also partake in the development of 3D bioprinting as a tool for developing artificial organs like the skin which can be used in case of burn and acid attack victims and also in pharmaceutical and cosmetic industries.
Written by – Parth Choudhari, Science Communicator, Nanomedicine Research Group.