3D Bioprinting - Future of organ transplantation

WRITTEN BY ISMAIL ARIF A, CLASS OF 2023

The highlight of this blog is the advancement of 3D organ bioprinting technology, which has the potential to eliminate the need for organ donors and transplant waiting lists. 

Organ transplantation is a life-changing event for a person in need. With the proceeding enhancements in modern medical technology, this essential procedure may suffice even without a human donor. 3D bioprinting is the use of biomaterials called bioinks to create threedimensional structures that are capable of imitating normal functional tissues. 

First ever bioprinting was attempted by Robert J. Klebe in 1988 when he used a Hewlett-Packard (HP) inkjet printer to print cells. Since then, bioprinting has gone through multiple developmental stages coming up with new methods, techniques and technologies. 

It all begins with the extraction of cells from patient’s body using minimally invasive small needle biopsy technique. After that, collected cells are grown in media inside an incubator. These incubators provide correct temperature and oxygenation for optimal growth of cells. The incubation period varies and mainly depends on the size of organ or tissue planned for printing. Next, bioink is created by mixing grown cells and its media with growth factors and hydrogels that ensures continued proliferation and differentiation of cells. Finally, this bioink is loaded into printing cartridges and printing process is started according to preprogrammed 3D image of organ prepared with patients imaging data from scans or X-rays. Printing process takes several hours and it is followed by putting printed tissue or organ in a bioreactor to allow for further maturation of cells before it is ready for transplantation. 

First ever full organ printing and transplantation was performed in 2004 when Luke Massella received a bladder which was printed in the laboratory of Boston Children’s Hospital, Massachusetts, USA. For Luke, who was 10 years old at that time, the whole process starting from biopsy to transplantation took just 2 months and his bladder did not have any complications from the transplantation since.

Using bioprinted autogenic organs instead of receiving organs from a donor will definitely be preferable as it comes with reduced complications since patients own cells are being cultivated and are less likely to have severe immune reactions against transplanted tissues. Patients who are getting organs from donors normally should have to be put on post-transplant immunosuppression therapy for the rest of their life. With 3D bioprinting from own cells, it becomes unnecessary to put patients under high dose immunosuppression therapy. 

It’s no surprise that demand outpaces supply when it comes to organ transplants, causing patients having to waitlist for years to get transplants. It is estimated that 17 people die each day waiting for an organ transplant and a new person is added to the transplant list every 10 minutes. 3D printing could potentially fill this organ deficit as it would only take 2 – 3 months to grow and bioprint instead of waiting for years in the waiting list. It would also be beneficial in situations when surgery is required on healthy donors such as donation of a kidney, as with 3D printing there is no need for a donor at all. 

For now, it may seem that 3D printing of organs is more expensive compared to getting a donor organ. However, when we consider all the factors revolving around the transplantation of organs from a donor, starting from the operative cost on donors, pre-operative duration and treatments that patient has to undergo while waiting for transplantation such as dialysis and postoperative regular check-ups, to lifelong immunosuppression therapy that is required, it can be said that 3D printing will be vastly cheaper for the patient on the long run and much less of a burden for the healthcare system. Moreover, costs for bioprinting are estimated to decrease as technology continues to advance. 

Recent breakthroughs are promising such as bioprinting of world's first 3D bioprinted heart in 2019 by researchers at Tel Aviv University. This heart was size of a cherry and still requires further improvements to achieve collaborated contractions of cardiomyocytes. Further research and development are still needed before it will become feasible to bioprint whole organs and one of the main challenges which scientists are working on is to find a suitable way to adequately perfuse organs. Proper vasculature structures with small capillaries are important for organs to maintain perfusion and to prevent cell death. Another challenge is the need for precision. Printing organs such as lungs or kidneys would require more precision as they are vastly more complex with more cells per centimeter compared to printing of a bladder.

Even with the tremendous progress that has been achieved, bioprinting of complete organs is yet far from perfect and wouldn’t be readily available to the public as soon as we hope it will, but scientists are confident that it would be possible in a decade’s time or less. When it does, demand for bioprinting is definitely expected to rise and it would be possible to “order” organs for patients instead of directing them towards a waiting list for organs. 

3D print of a heart about the size of a cherry, immersed in liquid, at Tel Aviv University 

Photo: Medical Xpress by Science X Network