Organ transplantation is a life-saving procedure where one person receives part or all of an organ from another individual. The person receiving the organ is usually in critical need of the transplant, and the procedure gives them a second chance at life.

However, the transplanted organ must come from a donor, and there are significantly fewer organ donors than people requiring transplants. Data from the United Network for Organ Sharing (UNOS) states that in the USA, almost 40,000 organ transplants were performed in 2020. However, over 108,000 people were registered candidates waiting for a life-saving organ transplant. Only 36% of people waiting for an organ transplant receive one, a percentage that is increasingly becoming of concern as the presence of end-stage organ disease continues to rise. Currently, the only sources of transplantable organs are living and deceased human donors. Living donors must undergo extensive surgery and rehabilitation, while deceased donors must have previously consented to organ donation and sustained minimal bodily injuries. All of these factors limit the availability of viable organs.

For some diseases, transplantation is the only treatment that can cure the disease. This is the case in end stage renal disease (ESRD), where kidney transplant is the only way a patient will no longer have to live with the disease. Unfortunately, the organ donation crisis has been a long-standing barrier to treatment of this disease and other chronic diseases like end-stage liver disease (ESLD) and heart disease. As the global population ages, the prevalence of such chronic conditions is on the rise. For example, ESRD cases have increased so much that the disease is now of acute political concern. In 2019, the US Government issued the Executive Order on Advancing American Kidney Health: a plan to have 80% of patients diagnosed with kidney disease in 2025 treated with either home dialysis or a kidney transplant. Unfortunately, there are simply not enough transplantable organs available for the treatment of people who are suffering. This is the case for many other chronic conditions, proving a critical need for solutions to the organ transplantation crisis.

One proposed solution is the development of ‘alternative organs’. The ability to create functional tissue and organs in a lab has been an attractive, yet unattainable theory, as previous technology could not recapitulate the complexity and detail required to create transplantable organs. However, as technology continues to advance, this theory has become more realistic. Bioprinted organs are now a very real possibility.  

Bioprinted organs have the potential to revolutionize organ transplantations, as they eliminate the need for organ donors, and can be used to save the lives of many who pass away while waiting for a life-saving organ transplant. Bioprinted organs consist of a collection of the patient’s own cells mixed with a biocompatible, biodegradable implantable scaffold, like GelMA, constructed into the shape of the organ using a bioprinter. A model of the organ is created using computer software and medical images of the patient which is then sent to a bioprinter that deposits the cell scaffold. The biocompatibility of bioprinted organs using GelMA mixed with host cells minimizes the chance of organ rejection, making the case for an effective device with lower risks than traditional organ transplant procedures.

Bioprinting is an excellent tool for the development of artificial organs because multiple structures using different bioinks can be printed simultaneously. The use of different cell types in conjunction with a highly versatile hydrogel, like GelMA, allows the multiple structures within a single organ to be printed. For example, the medulla, cortex, nephrons, and blood vessels of a kidney all contain different types of cells, however, they exist within the same structure.  Simultaneous printing reduces complications associated with generating various structures at different times and then attempting to integrate all structures into a single functional organ. The rapid nature of bioprinting will allow research and development streams to be expedited, improving the lives of more people, faster.

As the population ages and governments begin to bear the brunt of increased healthcare costs around the world, increased support from both government and private sectors is pushing us closer to a future with bioprinted organs.