by Nicole Basler
There are currently more than 120,000 men, women, and children in America who need life-saving organ transplants. While more than 1 million tissue transplants are performed each year, an average of 18 people die each day from the lack of available organs for transplant. Furthermore, another name is added to the national organ transplant waiting list every 10 minutes. The surgical need for tissue is increasing.
Despite the current strain of these numbers, the future possibility of synthesizing a 3D printed organ synthesized from a patient’s own cells presents hope. This technology, bioprinting, is a favorable alternative to satisfy the growing demand for human tissue and organs. It offers greater speed and computer precision in printing living cells to create replacement skin, body parts, and organs such as hearts, livers and kidneys. Although widespread public access to this technology is currently far from reality, university labs and private companies have used 3D bioprinting to synthesize such organs and tissue.
The process of 3D printing is based on the growth of stem cells according to a computer-generated model. Living cells are layered by an additive process. In other words, the cells are placed in a specific position, which allows them to self-organize and grow. The ink used for printing consists of live cells that are delivered from a nozzle, constructing layer by layer of cells to create a 3D tissue or organ. The cells used for bioprinting are derived from the patient’s individual stem cells, removed from his fat or bone marrow, which eliminates the possibility of transplant rejection from the patient’s body.
Stuart Williams, executive and scientific director of the Cardiovascular Innovation Institute’s efforts to synthesize a 3D printed heart attempted to simplify the biological process. He said, “We will be printing things on the order of tens of microns, or more like hundreds of microns, and then cells will undergo their biological developmental response in order to self-organize correctly.”
Thus far, bioprinting has achieved a fair level of success in its trials and tests. For instance, in May 2013, doctors saved a six-week old child with a 3D printed trachea. Recently, researchers in China have also claimed to succeed in printing a pair of kidneys for patients in need of transplants. In addition, in February 2013, doctors at Weill Cornell Medical College and biomedical engineers at Cornell University in New York announced they had used 3-D printing to synthesize a human ear that appears and functions like the real one.
Williams is optimistic of the potential of synthesizing organs through 3D bioprinting. He says, “Ultimately, I see it being used to print replacement kidneys, to print livers, and to print hearts — and all from your own cells.”
Despite considerable success, challenges to printing a functional tissue or organ still persist. These difficulties include the production of viable cells, creating a vascular system of branched vessels, generating the exact structural complexity of organs, such as the brain and heart, and integrating the cells into a functional network.
Keith Murphy, chairman and CEO of Organovo, a San Diego based company committed to designing tissue through bioprinting, admitted several difficulties in printing complex organs. He said, “If you do what we do with putting cells in the right place, you don’t start with anything structural to hold things up. For us, the challenge is the strength and integrity of the structure.”
Overall, 3D organ printing is a primitive technology which requires further trial and research before it is released as a safe and widespread innovation to the public. While bioprinting pioneers hope to fulfill the most complex organ transplants and necessities, even the smallest successes, such as tissue regeneration, can prove life-changing for many patients.