By Bella Rudoy
Four and a half years. That’s the average time people suffering from kidney failure wait on the transplant list. According to the National Kidney Foundation, over 3,000 new patients, on average, are added to kidney transplant wait lists each month, one person is added to the list every fourteen minutes, and thirteen people die each day as they wait. As dejected surgeons and devastated families bemoan these staggering numbers, bioengineers believe they may have found a solution: 3D-printing the kidneys that organ donors cannot supply.
3D-printers build up thousands of thin layers of material in order to produce the desired object. In biotech, 3D-printers are used to build layers of living cells mixed with other organic material to create what is known as ‘bioink’. This bioink is then used to print the tissue to constitute the desired organ. The organ is then treated with an ionic solution or UV light which allows it to stabilize.
The first printed “organ” was an ear for a patient suffering from microtia, a disease in which an individual is born with one ear and suffers from severely affected hearing. In July 2022, 3DBio Therapeutics successfully 3D-printed an ear for this patient with their own cells and then successfully implanted it onto the patient, immensely improving her quality of life.
In recent months, skin has also been 3D printed, helping patients suffering from severe wounds. The 3D printed skin has shown promising results in animal testing; when it was implanted onto mice, it began to connect with the mice’s existing blood vessels rather than just falling off their bodies. Even more astonishing, is that a 3D-printed bladder has successfully sustained the life of a patient suffering from a defective bladder. With a sample of this patient’s bladder tissue, a bladder was 3D printed in just two months and then successfully transplanted into the patient.
Although the 3D-printed ear and bladder were a considerable success, bioengineers’ ultimate goal is to 3D print more complex organs such as the kidney. Bladders are very simple organs that hold only two cell types, while kidneys are far more complex and hold over twenty kinds of cells. Although 3D-printing complex organs seem to be years away, progress has been made. In 2019, Israeli researchers successfully 3D-printed an entire heart, but it was too small to function properly in a human body. Aside from scaling up this tiny heart, complete with a vascular system, scientists aren’t sure yet if the 3D structure would be able to hold the flow of blood at such a high pressure or if the structure would remain stable within a human body.
While there have been some setbacks from other organs, the potential advantages of bioprinting kidneys have caused bioengineers to strive to discover how to properly print such a complex organ that would successfully function in the human body. Researchers are attempting to use a patient’s own stem cells to print kidneys, as they did with the successfully printed ear. This has shown to be more effective than the previous approach of creating scaffolds– structures of materials on which new tissue can be grown– as 3D scaffolds made it difficult for cells to distribute and develop properly. Additionally, utilizing stem cells has been shown to reduce the risk of rejection from the body, which is one of the leading causes of post-operative death for transplant patients.
CollPlant, a leading biotech company, has already been working on 3D-printing lungs and has recently begun its work on 3D- printable kidneys. Stem cells have been successfully 3D-printed as parts of these complex organs, but the bioengineers still need to discern a way to utilize these stem cells to regenerate kidneys. Nevertheless, based on the research being conducted, it seems that a patient waiting for a kidney transplant for four and a half years will be a notion of the past as the new, custom-printed, one-hour kidney begins to revolutionize and transform our future.
Organ Donation and Transplantation Statistics | National Kidney Foundation
NIHF Inductee Charles Hull, Who Invented the 3D Printer
👂When Will We Have 3D Printed Organs? – by Jamie (substack.com)
6 Exciting 3D Printed Organs & 3D Bioprinting Projects – 3DSourced
3D Printed Kidneys: How Close Are We? – 3DSourced
Bladder grown from 3D bioprinted tissue continues to function after 14 years – 3D Printing Industry
3D-printed scaffold engineered to grow complex tissues | National Institutes of Health (NIH)