The Future of Engineering Organs
Joseph Hall
(847) 942-0403
josephfh@usc.edu
Abstract: A major problem facing the health community is the lack of organs available
to patients in need of a transplant. The current system of finding organs for patients
can’t keep up with the demand for organs. The development of a new technology called
bioprinting has allowed researchers to print organs using a 3-D printer using human
cells as the building material. There is such a need for this technology that it has the
potential to become a multibillion-dollar industry. There have been enormous
advancements in this technology and it is the hope of researchers that one day, organs
will be able to be printed right into a patient.
Bio: I am a junior majoring in Biomedical Engineering. In addition to being a student in
the Viterbi School of Engineering I am also a member of the USC men’s club lacrosse
team.
Keywords to search: Health & Medicine, Biomedical Engineering
Joseph Hall
Writ 340
3/8/12
The Future of Engineering Organs
Introduction:
A man suffering from heart disease, a woman with kidney damage, and a child in
need of bone marrow all have one thing in common; each one of them is in need of an
organ donor. Over 113,000 people in the United States and millions more globally are
currently waiting for an organ transplant [1]. The organs that these patients could be
waiting for include but aren’t limited to a heart, kidney, liver, eyes, or bone marrow.
Patients in need of an organ transplant can spend years on the donor list waiting to find a
match and many die while they’re still on the transplant list. In fact, 18 people each day
die while waiting for an organ [1]. It can be extremely difficult to find an organ for a
patient waiting for a transplant because there is such a limited quantity of organs being
donated. Over the past decade the demand for organ transplants has more than doubled
so this will make it even more difficult to find organs for those in need[2]. What makes it
even more difficult to find an organ for a patient is even if an organ is available there is
no guarantee that the organ will be a match for a patient.
Currently it is extremely tough to receive an organ donation if you are really in
need of one. People volunteer to be organ donors and only when they pass away will
their organs will be donated to those in need. Even though a single donor can save up to
eight lives there’s still an extremely large demand for transplantable organs [1]. Even if
there are organs available to be transplanted the next hurdle becomes finding an organ
that won’t be rejected by the recipient. There are proteins on the surface of every tissue
in our bodies so our immune systems can determine when something foreign has entered
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the body. If a patient receives an organ with surface proteins that their immune system
doesn’t recognize then the body will reject the organ and the organ will shut down [3].
The problem of finding an organ donor would be permanently solved if we could create
organs on demand and guarantee that the recipient’s body would accept the organs.
Process to 3-D Print Organs:
Over the last few years, incredible advancements have been made in the field of
bioprinting, a new technology that can 3-D print organs. 3-D printers use a technology
that is very similar to standard inkjet printers. A computer sends a design to the printer
and a printer head moves back and forth laying very thin layers of a material on top of
each other until the three dimensional structure has been created. The process of printing
organs is similar to printing non-biological structures except the material that’s being
used is human cells.
The process begins by taking a small tissue
sample from the patient in need of an organ donation.
These cells can be muscle, liver, kidney, or any cells
necessary to build a new organ. These cells are then
harvested and grown until there are enough to form
the tissue needed to create the organ. The patient
then undergoes a CT scan, or an x-ray, to build a 3-D
image of the damaged organ on the computer. This
Figure 1: Computer
representation of an organ to
tell the printer where to place
the cells (Washington post)
image will tell the printer the exact dimensions that
are needed for the organ to fit in the patient. The printer puts down layers of a mixture of
cells and a binding agent less than half of a millimeter thick. The cells are the functional
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part of the organ while the binding
agent holds the cells together long
enough for them to mature together.
In order to solidify the layers the
organ is exposed to a UV light after
the addition of each layer. Once the
whole organ has been printed it is
incubated and tested before it is
implanted into the patient [4]. Since
the new organ was created from cells taken
Figure 2:A schematic of the 3-D printer
(Washington Post)
from the patient, it is guaranteed that the immune system will recognize the cells and
there is no risk that the patient’s body will reject the organ.
Current Use of Bioprinting:
One of the biggest difficulties of printing an organ is getting the cells to mature
and work together to form tissue that can become a functioning organ. While the
technology described above hasn’t yet produced a functional organ because the cells
don’t interact with each other correctly, researchers have achieved success using a similar
strategy. Dr. Anthony Atala from Wake Forest University has successfully bioprinted
and implanted into patients several functional bladders using a scaffolding technique. He
simply took tissue samples from patients and isolated the muscle cells for the surface of
the bladder and the specialized cells that he needed to create bladder could function
normally. These cells were then printed onto a biodegradable scaffold that helped to hold
the shape of the bladder. After the cells multiplied, the bladder was implanted in the
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patient and the biodegradable scaffold disappeared over time. These surgeries took place
in 2006 and each of the bladders created are still functional in patients [5]. Although this
scaffolding technique can produce a functioning organ the possible uses of it are limited.
Not only is the process less precise than newer methods of bioprinting, it is also slow and
costly as the process cannot be as automated [6].
Moving Towards New Technology:
The benefit of using a bioprinter to print layers of cells on top of each other is that
you don’t need the scaffold to hold the cells in place. This feature allows for more
customizable organs. Doctors wouldn’t be limited to only implanting organs with a
specific size and shape of the scaffolds be can create an organ that will fit inside any
patient perfectly. Maybe the most exciting feature that the new method of bioprinting
offers is the ability to build a vascular tree directly into the organ [7]. Organs cannot
function without a blood supply and the organs created by this bioprinting technique will
be self-sustaining because they will have built in blood vessels.
This technology is still years away from clinical trials in humans but the
advancements in research offer some very exciting opportunities for the medical field. It
is projected that in as soon as two years bioprinted joint cartilage, nerves, and meniscus
tissue will be implanted in human trials. A little farther down the line, within ten years,
we should start seeing people with bioprinted tracheas, heart valves, and ligaments [4].
The last hurdle will be implanting large organs such as the heart, liver, kidney, and lungs.
Other Areas Where Bioprinting is Useful:
Although the technology to print entire organs is still a ways away, a bioprinting
device to help replace the skin on burn victims is already functional. The tool works in a
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similar way to the 3-D printer except it prints directly onto the injured person. After
someone suffers a severe burn the device scans the burn area to determine the extent of
the damage. It then concludes how many layers of cells it needs to lay down on each
place of the wound in order to return the area to its normal state. A device that acts as a
printer head lays down thin layers of skin cells until it’s as if the patient was never burned
[8].
Another area of the health field where the three dimensional printing of organs
will be beneficial is in the pharmaceutical industry [2]. For a drug to get FDA approval it
must undergo years of clinical trials to demonstrate it won’t be harmful to a human’s
body. If a drug has adverse effects these trials can be extremely detrimental to the user’s
health. Some pharmaceutical companies are working to test their drugs on printed tissues
so they can see if their drugs cause damage to human tissue before any person has to test
the drug.
Conclusion:
With the continued
advancement of bioprinting, over
one hundred thousand patients in
the United States alone could be the
recipients of organs that they
desperately need and it would be
guaranteed that these organs would
be matches. This technology still
has to progress before it becomes
Figure 3: The Future of Medicine? (The
Economist)
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readily available to create organs for anyone who needs one but the progress being made
each year is extremely promising. For example, Dr. Bonassar from Cornell University
has already successfully printed cartilage directly onto bone. It is the belief of
researchers that one day we will have machines that directly print whole organs into
patients instead of printing them outside of the body and implanting them after they’ve
developed. The future should be promising as research will continue as it is projected
that the market for bioprinting will generate $50 billion over the next thirty years [9].
Considering doctors are able to print skin tissue and have already successfully printed
and implanted functional organs in patients the sky is the limit for where this technology
can go.
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[1] U.S. Department of Health and Human Services. [Online]. Available:
http://organdonor.gov/index.html.
[2] R. King, “Bioprinting: The 3D Future of Organ Transplants?” Businessweek Internet:
http://www.businessweek.com/technology/bioprinting-the-3d-future-of-organtransplants-01092012.html, January 9, 2012.
[3] National Library of Medicine/National Institute of Health. Transplant Rejection
[Online]. Available: http://www.nlm.nih.gov/medlineplus/ency/article /000815.htm.
[4] B. Berkowitz & T. Linderman, “How Bioprinting Works,” The Washington Post
Internet: http://www.washingtonpost.com/wp-srv/special/science/how-bioprintingworks/, May 9, 2011.
[5] D. Simonds, “Printing Body Parts: Making a Bit of Me,” The Economist Internet:
http://www.economist.com/node/15543683, February 18, 2012
[6] V. Mironov, V. Kasyanov, & R. Markwald, “Bioprinting: Directed Tissue SelfAssembly,” Chemical Engineering Progress, vol. 103, no. 12, December, 2007.
[7] B. Graca & G. Filardo, “Vascular Bioprinting,” The American Journal of Cardiology,
vol. 107, no. 1, pp. 141-142, January, 2011.
[8] K. Zetter, “TED 2011: Print-On-Demand Organs the Future of Medicine,” Wired
Internet: http://www.wired.com/epicenter/2011/03/anthony-atala-at-ted/2/, March 7,
2011.
[9] P.R. Fernandes, “Biofabrication Strategies for Tissue Engineering,” in Advances on
Modeling in Tissue Engineering. New York: Springer, 2011, ch. 8.
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