Conference Session A6
Paper #39
Disclaimer — This paper partially fulfills a writing requirement for first year (freshman) engineering students at the University
of Pittsburgh Swanson School of Engineering. This paper is a student, not a professional, paper. This paper is based on
publicly available information and may not be provide complete analyses of all relevant data. If this paper is used for any
purpose other than these authors’ partial fulfillment of a writing requirement for first year (freshman) engineering students at
the University of Pittsburgh Swanson School of Engineering, the user does so at his or her own risk.
IMPROVING THE GEL-SUPPORTED MANUFACTURING PROCESS OF 3DPRINTED ORGANS
Daniel Chu, [email protected], Mena 3:00, Abigail Pinto, [email protected], Vidic 2:00
Abstract — Bioprinters are transforming the medical field as
three-dimensional printers that can artificially replicate
portions or even whole organs for human patients. One of the
largest obstacles in the manufacturing of the artificial organs
is the preservation of the biomaterial during production.
Bioink, the vital substance in bioprinting, contains
reproduced, living cells from the patient. Due to its fragile
state, bioink’s integrity can be compromised by its
environment over time. If the bioink preservation and the
printing process are improved, the bioprinting operation
would be more economical, with organs being available at a
more practical amount of time and in greater quantities.
While a variety of bioprinting methods are currently being
explored, this paper will focus on the inkjet technique because
of its wider range of opportunities. With methods such as
inkjet bioprinting, 3D-printed organ replacements are
expected to be much cheaper than the alternative of
transplants. Yet, as a currently developing technology, the
bioprinters for artificial organs are not yet ideal and the
process would benefit from improvements. The ideal
bioprinter must be efficient, easy to use, and produce reliable
prosthetics, yet still be affordable for the average patient. The
viability for this technology holds undeniable promise since
the technology to artificially create fully-functional organs
directly involves the sustainability of lives. This paper will
convey the issues in the current bioprinting process, their
possible solutions, and the potential ramifications of
bioprinting on patients, the economy, and the manufacturing
industry.
improving the situation would clearly save lives. Transplant
technology has progressed with new machines and greater
knowledge of human anatomy. However, the lack of suitable
organs still posed a major issue.
Recently, three-dimensional (3D) printing offers a
promising solution to this shortage. With the ability to
recreate almost any object with the proper computer input
directions, 3D printers construct their products by layering ink
in a specific order to form the desired model. This ink can be
composed of a variety of materials, ranging from plastic to
metal to even organic materials. For the past decade,
researchers have been studying how to use 3D printers to
manufacture fully-functional prosthetics to replace damaged
organs. The “sustainability” of bioprinting relates to how long
the technology will be relevant, accessible, and efficient.
Although still in development for now, bioprinting is the most
sustainable approach to organ transplantation. The
sustainability of bioprinting is a vital component of the
technology itself. Bioprinting has the capacity to save lives
and the prosthetic must last, rather than purely be a short-term
solution. If successful, this breakthrough will create a
tremendous amount of opportunities for innovation as
biomanufacturing will affect the medical field, the economy,
the manufacturing industry, and lives around the world.
History of Bioprinting
Although 3D printing has existed for more than twenty
years, it has primarily been utilized in prototyping and smallindustry production [2]. 3D printers originated from the twodimensional inkjet printers of offices and personal computers
in the 1980s. In 2001, engineers began replacing the
traditional ink in printers with bioink, which resulted in the
creation of the first tissue-engineered bladder with organic
cells on a synthetic scaffold. Cells are “seeded” onto a solid
support structure to form an interconnected network of pores
[3]. These 3D printers made specifically for use in the medical
field are known as bioprinters. Instead of ink, bioprinters layer
cells and other biomaterials to fuse into tissue constructs.
According to Manufacturing Business Technology, the
current average manufacturing process is defined as a
“subtractive process,” where 60 to 70 percent of the raw
material becomes scrap after the product is completed [4].
Key Words – Bioink, Bioprinting, Prosthetic Kidneys, 3DPrinting, Inkjet Bioprinting, Artificial Organs, Sustainability
3D PRINTING IN THE MEDICAL FIELD
According to the United Network for Organ Sharing,
almost 120,000 people are on the waiting list for a vital organ
transplant [1]. Not only are traditional organ transplants
expensive and sensitive procedures, but the number of people
waiting for operations is much larger than the current number
of applicable donors. The number of patients in the United
States in need of an organ transplant increases by one every
ten minutes [1]. In the case of organs, lives are at stake and
University of Pittsburgh Swanson School of Engineering
03.31.2017
1
Daniel Chu
Abigail Pinto
Manufacturers begin with a large quantity and subtract pieces
until they form their desired design. To save money and lower
expenses, the scrap is melted to be added back to the general
supply for the next product.
By contrast, 3D printing, which includes bioprinting as
well, is an “additive process” [4]. With printing,
manufacturers use only the minimum amount of material
needed to construct a product, without having to purchase an
overabundance of material from which they would have to
subtract. The additive process eventually decreases the
expenses for the manufacturers which can decrease costs for
the consumer, who is the patient in the case of bioprinting.
Compared to subtractive processes, additive processes reduce
waste and is much more cost efficient. When the process
saves materials, businesses save money when they do not
need to purchase so much raw material. As a subgroup within
3D printing, bioprinting’s manufacturing efficiency is
evidence of its aspects of sustainability. Since 2001,
bioprinting development has been slow but recently, new
research and technology holds promising results for artificial
organs.
bioprinting develops and produces fully-functional
organs. There is great potential in bioprinting organs and as
the field attracts more attention, the technology has a growing
chance to reach the ideal level of functionality and success.
FIGURE 1 [8]
Kidney in Mid-Printing
BIOPRINTED ORGANS
Benefits Compared to Organ Transplants
Bioprinters are the specialization of 3D printers that are
revolutionizing the future of the medical field. There is a
plethora of medical uses for 3D printing including
replacements for bones, ears, windpipes, exoskeletons, jaw
bones, cell cultures, stem cells, blood vessels, vascular
networks, tissues, and organs [5]. Organs are one of the most
difficult structures to print due to their complex cell matrices
and intricate intravascular systems. Less complex organs
allow printers to create just a general scaffold that biomaterial
will adhere to separately which simplifies the process
dramatically [6]. For now, only relatively simple organs, such
as bladders, have been printed and transplanted into actual
human patients as fully-functional prosthetic organs.
Bioprinting can improve and even save the lives of
thousands of people in the United States alone. One story of
success is about Luke Massella, who was born with spina
bifida, a birth defect affecting the spinal cord that can cause
multiple organs to fail. Luke’s bladder was leaking into his
kidney so Dr. Anthony Atala used Luke’s own urothelial
cells to 3D print him a custom bladder. He was ten-years-old
at the time but has since graduated from high school and
enrolled at the University of Connecticut, currently living the
life of an average young adult [7].
At the moment, bioprinted replacements for complex
organs, such as kidneys, are not yet to the functional standards
but can be utilized as models for surgical practice and testing.
For a surgeon or medical student to be able to practice on an
accurate replica, like the one in Figure 1 below, is extremely
valuable in the preparation of an operation. Even nonfunctioning bioprinted products can still be relevant in the
medical field for simulations and visualizations. This aspect
of sustainability will be joined by additional applications as
The ability to use the patient’s own cells gives
bioprinted organs a significant advantage over traditional
transplants for achieving success. The cells are biopsied from
the patient’s original organ and later replicated in a lab to be
used in bioink, which is printed to form the prosthetic. A
bioprinted organ of the same size, shape, molecular structure,
and cell composition has a drastically reduced chance of being
rejected by the new host body. In traditional organ operations,
transplant rejection occurs when the body recognizes a
foreign compound and the immune system attacks the new
organ. An identical replacement for the failing organ is much
more likely to be accepted when it is comprised of familiar
cells [9]. Even if a donated organ is not rejected, there is a
chance that the new organ will also fail at later date and the
patient would have to rely on another donor. Coupled with the
limited availability of applicable donors, this uncertainty
makes traditional organ transplants a less sustainable method
compared to bioprinting. Bioprinters can eliminate both of
those issues with its potential to perpetually construct
replacement organs that are more likely to acclimate to the
body.
The current transplant process is also inferior due to the
procedure’s requirement of two invasive surgeries: one for the
donor and another for the patient. When compared to
bioprinting, which does not involve a donor, the traditional
transplant method is an efficient use of resources and time. As
it is dangerous for the patient to live with a single kidney, a
donor adopts the same risk when participating in a transplant
procedure. In 2016, more than five thousand people donated
their kidneys for someone in need [10]. Bioprinting can save
2
Daniel Chu
Abigail Pinto
almost everyone who needs an organ, while eliminating the
need for others to sacrifice and endanger their own health.
With this technology, people will not have to be wholly
dependent on a compatible organ donor. With a high chance
of becoming the primary method of treating organ issues in
the future, bioprinting would surpass donor-reliant transplants
because of its self-sustaining nature.
platform, as seen in Figure 2. This method is nozzle-free,
which reduces shear stress on the cells, but the bioink must
have a low viscosity for fast crosslinking and weaving of the
structure’s components [12].
Extrusion-based bioprinting inserts the bioink into
syringes and mechanically or pneumatically dispenses it onto
the receiving substrate. Mechanical dispenser uses a solid
plunger while pneumatic dispensers utilize a gas to expel the
substance. Unlike inkjet and laser-assisted, extrusion
bioprinting dispenses the bioink in large hydrogel filaments,
about 150 to 300 μm in diameter, rather than in droplets.
Larger pressure drops risk disrupting the suspended cells,
damaging their matrix, and resulting in cell death [12]. Figure
2 demonstrates the difference in consistency and thickness in
the stream of bioink expelled from the extrusion printer as
compared to the drops of bioink produced by the other
printers.
3D PRINTING WITH BIOINK
The first cell-printing bioprinter and the most widelyused bioprinter today is the inkjet bioprinter. Also known as
“drop on demand,” this computer-controlled technique
precisely releases droplets of bioink of 1 to 300 picoliters in
specific locations to form a complex structure [11]. Inkjet
printers are also capable of printing bioink with viscosities of
3.5 to 12 mPa/s and low cell densities of less than one million
cells per milliliter, which in cases of certain organs is a large
advantage [11]. A low viscosity mean that the ink flows out
of the nozzle at a quicker and potentially smoother rate. Not
requiring contact with the printing surface puts less stress on
the bioink and decrease the chance for contamination from the
nozzle.
Printing Process
The first step in the bioprinting procedure is taking a
magnetic resonance image (MRI) or computerized
tomography (CT) scan of the target organ. These provide 3D
images that are loaded onto a computer where computer-aided
drafting (CAD) software builds a corresponding 3D blueprint
of the organ. A slice-by-slice computer model is then created
by scientists with extensive knowledge of the microscopic
cellular matrix [6]. This information is sent to the bioprinter
and the printing begins.
During bioprinting, the bioink is stored in a reservoir or
cartridge and transferred to an ink chamber to be ejected
through the print nozzle onto the printing surface. Print heads
pump the material onto the platform in the specific
arrangement using the triangulation sensors that tracks the tip
of the print heads as they move throughout the three axes [6].
While the general process of bioink printers are
fundamentally similar, the specific methods of depositing the
bioink differ greatly.
FIGURE 2 [13]
Illustrate Comparison between inkjet bioprinters,
extrusion bioprinters, and laser-assisted bioprinters
Compared to other bioprinter method, inkjet have a
significantly higher fabrication rate of 100,000 droplets per
second. They are also superior when it comes to resolution,
achieving 100 µm compared to the next highest resolution of
10 to 50 µm from laser-assisted bioprinting. Although laserassisted printing has a slightly higher cell viability, inkjets
still has an 85% cell prosperity [14]. These printers have a
high compatibility with a wide range of materials, making
inkjet bioprinters more versatile to print more types of organs
than the other designs. Inkjet printers work the fastest, cost
the cheapest, and use the least amount of raw material while
still producing quality biomaterial. At this point in the
development of bioprinting technology, inkjet printers have
the greatest propensity to be the most viable option for
efficiently producing prosthetic organs.
Comparing Bioink Printing Techniques
Inkjet Bioprinting
There are three prevailing types of bioink printing: laserassisted, extrusion, and inkjet. Each has its benefits and
drawbacks, but all three share the commonality of utilizing
the patient’s cells in bioink. Laser-assisted bioprinting
involves a donor substrate surface covered in a layer of bioink
and coated in an absorbent layer, such as titanium or gold. A
pulsed laser beam scans the donor substrate as the focal point
of the beam causes the absorbent layer to evaporate, forming
high-pressure bubbles that force the bioink toward a collector
There are two main types of inkjet printing, thermal and
piezoelectric, distinguished by how the bioink is ejected from
the ink chamber. Thermal printing uses a heating element to
superheat the bioink creating a vapor bubble which forces the
ink out. The ink head is electrically heated on either side from
200°C to 300°C, which engenders the small air bubbles. The
bubbles produce pressure pulses that expel droplets of the
bioink from the nozzle in controlled volumes. The droplet
3
Daniel Chu
Abigail Pinto
size, as mentioned earlier, ranges from 1 to 300 picoliters and
is dependent on frequency of current pulse and the applied
temperature gradient [15]. Despite the extreme heat,
numerous studies have demonstrated that the actual print head
and subsequent bioink only experience an increase in
temperature of 4 to 10°C due to their short exposure of two
microseconds [16].
The alternative way to approach inkjet printing is the
piezoelectric method. When a voltage pulse is applied to a
piezoelectric crystalline material, the shape deformation
causes a volume change of the ink in the pressure chamber to
generate an acoustic wave. The acoustic wave propagates in
the print head and breaks the liquid bioink into droplets at
regular intervals to be expelled from the nozzle [11]. As seen
in Figure 3 below, both the thermal and piezoelectric have the
same basic structure of the print head. They also form the
similar droplets of bioink, but differ by how they force the
bioink out of the nozzle. Surface tension also determines the
extent of droplet formation. Since droplets can only develop
when the surface tension is weaker than the charges on the
surface of the bioink. The higher the cell concentration in the
bioink, the lower the surface tension since more cells are
absorbed into the liquid-gas interface [12].
significantly impacts printability. The cells incorporation
alters the ability for the bioink to flow so in order for the inkjet
printing method to be viable the printed material must remain
in the liquid state [12].
The hydrogel element is a combination of chemical
compounds that vary with the type of cells involved, the
environmental conditions, the printing method being applied,
and the final product. The complex hydrogel has many factors
affecting its printability including flow, surface tension,
swelling properties, and the gelation kinetics. In another
bioprinting technique, hydrogel fixation, the hydrogel
provides support as it maintains the shape of the bioprinted
structure through gelation. Many studies have been conducted
to prove that cells surrounded by hydrogel materials have the
highest survival rate [18]. One study used methacrylamidemodified gelatin hydrogels with a suspension degree of 62%
which resulted in a 97% cell survival while maintaining the
cell properties of the liver- specific functions [12]. Figure 4
below illustrates the biogel process in relation to the
construction of the organ. Biogel and bioink are the major
contributors to the sustainability of bioprinting since they are
components to the organic cells’ survival. Without the
biomaterial substances, the artificial organ would be less
likely to be accepted by the body and the prosthetic’s
functionality would decrease drastically. As bioink is
developed through exploration, the cells will eventually be
able to survive in a greater variety of surroundings and for
longer periods of time in between biopsies and prosthetic
production. Yet despite bioprinting’s progress, the
technology’s success is currently inhibited by certain factors,
preventing fully-functional, complex prosthetic organs from
being reached at the moment.
FIGURE 3 [17]
Illustrated comparison between thermal and
piezoelectric inkjet printers
Bioink is the most crucial component of the bioprinting
process for any method of printing and the greatest difference
between printing metal or plastic to printing a living,
functional organ. The bioink is the biomaterial substance that
is distributed from the printer head nozzle. The bioink is
composed of many different substances to achieve optimal
viability for the product. The most vital element in the bioink
is the cells that have been taken from the patient through the
means of a biopsy of the original organ or one of similar
composition. The cells are cultured and placed in a hydrogel
substance designed to support their survival and protection
during the printing process. A higher initial density of cells
leads to faster tissue formation, but the larger presence of cells
FIGURE 4 [19]
The Biogel Process
PROBLEMS IN PRODUCTION
Because bioprinting is still a developing technology,
there are still many avenues for improvement in the
production of artificial organs. Many of the bioprinter systems
4
Daniel Chu
Abigail Pinto
lack operation monitoring tools to regulate the process [2].
The complex geometric components within certain organs,
such as the kidney and its cell matrices, are difficult to test
and characterize. The three main problematic areas are the
variety of the biomaterials, the quality of the bioprinters, and
the financial cost related to the printing process.
takes time but researchers are attempting to devise a
technology to accelerate the cellular maturation after tissue
construction and even maturation of the cells in the bioink [3].
A greater variety of biomaterials correlates to a wider
spectrum of medical applications and the improved viabilities
of the cells and the technology itself.
Bioprinting has not yet achieved fully-functional organs
due to difficulty in incorporating the vascular system to allow
blood flow throughout the prosthetic [3]. The prosthetic
requires a certain degree of permeability to replace the
original but also enough rigidity to retain its shape. Expanding
the diversity within the biomaterial supply would support
bioprinting’s sustainability by increasing the survivability of
the cells and therefore the organs.
Variety of Biomaterials
Currently, the largest hindrance to bioprinting’s overall
success is the preservation of the bioink. The biomaterial is
incredibly vital in acclimating the body to the prosthetic
organ. Because the current process is so reliant on bioink
currently, the preservation of the organic materials is vital to
the success of bioprinting. Researchers are concerned about
the survivability of the cells that require high metabolic
processes to survive [3]. Because the cells are closely stacked
together before being printed, the cells’ health can be
compromised before the organ is even constructed. The
biomaterial requires a controlled temperature, proper oxygen
supply, and sterile surrounding while the printer layers the
structure [3]. Currently, the quality of the prosthetic organ is
limited of the composition of the material being distributed by
the bioprinter. Yet with more advancements in bioink
development, the biomaterial will hopefully sustain the living
cells inside the ink to be stored and later printed.
The composition of the biomaterial refers to its identity
as a powder or a gel. If the biomaterial is powder-based, the
printed construct is formed by heating the powder and fusing
the sections together [20]. If the microenvironment is not at a
controlled temperature, the heating process can be disrupted
resulting in the powder fusing in the wrong way or not
solidifying enough. Before printing, the suspended cells in the
bioink are liable to sedimentation or clotting in the reservoir.
While thermal inkjet printing uses high heat, the bioink only
experiences the extreme degree of temperature for
microseconds in order to be printed. Unaccounted heat can
cause the bioink to clot inside the printer and prevent
expenditure [14]. Bioink is also limited by the necessity of
organic solvents, such as the microgel, to house the cell [3].
The cells in the microgel risk decomposition at higher
temperatures, making temperature control even more vital to
the process.
Another material limitation to bioprinting is the lack of
diversity in functioning bioink that has high cell density. With
low cell density, the artificial organs are weak and flimsy.
Current bioink faces the issue of being too concentrated in
some sections, therefore forming lumps, or being not
concentrated enough in other regions, where ruptures can
easily occur [3]. The current biomaterial pool limits
bioprinters to only the methods and organs that are
compatible. For example, fully-functional kidneys, which
require complex cell matrices within them, are presently
unable to be bioprinted. Furthermore, the printed tissues need
to mature after printing, similar to how a freshly printed page
must dry or the image would smear. The maturation phase
Quality of Bioprinters
In addition to the materials that compose the bioprinted
organ, the success of the product also relies on the quality of
the machine that constructs the prosthetic. The bioprinters
have improved greatly since their conception in the 1980s, yet
still require technical progress to better print the organs. The
technology of the bioprinter would benefit from
advancements in the resolution, compactness, and accuracy of
the machine itself [3]. Almost every design suffers from
insufficient nozzle and ink cartridge structures [3].
Specifically, in the case of inkjet bioprinters, the nozzle’s
narrow design is liable to being clogged by residual bioink
due to cellular aggregation. The clotting adds detrimental
pressure on the cells and can result in irregular droplet sizes
when printing. Surfactants are substances that decrease
surface tension between substances but current surfactants are
incompatible with the bioink and risk compromising the cells’
health [14]. To resolve this problem, designers must account
for this tendency of accumulation of bioink without affecting
the cell’s viability.
Until recently, technological issues also hindered the
progress of bioprinting. Many bioprinters do not have the
necessary process monitoring and feedback response to
control the prosthetic printing process during the actual
printing [2]. The rapid advancement in computer capabilities
has helped make a substantial amount of progress, but
computing improvements are still necessary in improving the
bioprinting process. In order to print an organ, one must have
intricate knowledge of the organ and its functions, as well as
how to convey that information into a design code that the
bioprinter can understand. Codes for any bioprinter require
expert knowledge to give the printer precise directions.
STereoLithography (STL) files are the current standard input,
many bioprinters require their own unique software and file
formats to function properly [2]. With nonuniform coding
inputs, it is much more difficult to transfer prosthetic organ
designs from printer to printer. If every bioprinter accepted
STL files, bioprinted organs could be produced at a much
quicker and more efficient rate, which would allow
distribution to patients to also expand. The process of
5
Daniel Chu
Abigail Pinto
bioprinting would be more accessible to hospitals, and
therefore patients, via the digital transferring of information.
As computer programming and technology improves at their
current rate, bioprinting will continue to be sustainable since
the convenient connections makes bioprinting the most
optimal solution.
more [3]. As printer performance, accuracy, and supply
improve, bioprinting will have a lasting, if not permanent,
effect on the economy and on the manufacturing industry as a
sustainable technology.
Financial Cost
As of 2015, the Carnegie Mellon team has successfully
bioprinted living tissue with a simple printer that only cost
$1000 [21]. The researchers later reported their results,
saying, “Not only is the cost low, but by using open-source
software, we have access to fine-tune the print parameters,
optimize what we’re doing and maximize the quality of what
we’re printing” [21]. Currently, specialized bioprinters are
expensive, but once the technology develops further, prices
will start to decrease. Once bioprinters achieve success,
competition will rise among bioprinting companies as
different designs improve upon one another.
With cost savings, the suppliers would have to find a
balance between reducing their prices for consumers in order
to retain business from competitors and keeping a portion of
the saved expenses as increased profits [4]. This means that
people in need will have an easier time receiving an organ
replacement. Their health would not be relying on the next
available transplant, which has no definitive due date, but
rather a bioprinter that would be able to construct a fullyfunctional prosthetic organ in a matter of days. There is a large
chance that the increase use of the 3D printers, not just
bioprinters, will revolutionize the medical industry and how
manufacturing lines function.
The Economy
The technology to bioprint a three-dimensional structure
involves the aforementioned complicated process, which
currently includes high costs. Until 2005, every 3D printer
was expensive, privately-owned, or made for manufacturing
[3]. In 2014, a specialized three-dimensional bioprinter could
cost from $100,000 to $200,000, depending on the designed
capabilities of the machine [21][3]. However, simpler
bioprinters could cost less than $20,000 to build [3].
The steep price for bioprinting is not due to just the
mechanical components but also the bioink that would
constantly need to be refilled. Because of bioink’s vulnerable
nature, the printing material remains expensive to store and
ruined bioink adds an additional charge to replace. However,
as the quality of bioink improves with research and the threedimensional printers become more common and successful,
expenses for bioprinting will decrease. Engineers will be
largely influential in this because bioengineers will better the
designs and industrial engineers will cut wasteful processes
from the production operation. A decrease in expenses means
patients have easier accessibility to the replacement organs
that they need and the more affordable the products are, the
longer the technology would be sustained.
The Manufacturing Industry
POTENTIAL IMPACT
With STL files that can be manipulated and ideally
understood by any 3D printer, companies will be able to
produce anything they can imagine as production constraints
become more trivial [2]. Bioprinters have already reached
skin grafts, which transplants skin on severe burn wounds and
other cases of trauma. Beyond organs, bioprinters could
expand to muscles, more realistic prosthetic limbs, and
perhaps even high functioning organs like eyes and ears in the
future. Companies traditionally work the supply chain,
transferring the product between the stages of manufacturing.
Yet with 3D printers, design and production will be more
intertwined before as they are connected in the
experimentation phase [2].
Similar to almost any other case of 3D printing,
bioprinters will localize the production process if the ideal
bioprinter prints the prosthetic organ in the same place as the
patient. Bioprinters’ relatively compact design makes housing
it in a hospital feasible and if a specialist inputs the necessary
design, the patient in need could receive their new organ in a
matter of days. If bioink is improved, the wait time would be
decreased even more. The production process for bioprinting
will be continually improved over the years as businesses and
industrial engineers analyze and refine the manufacturing
As of right now, bioprinting fully-functional organs is
out of reach, remaining in a “state of science fiction” [3]. As
the diversity of materials grows, researchers suggest using
synthesis to mix material compositions [20]. To increase
cellular health stability, bioprinting is emphasizing more on
the microgel, using cell-laden hydrogel microcarriers that can
increase cell concentration within the ink [3].
One of the leading teams in bioprinting development is
led by Adam Feinberg, an associate professor at Carnegie
Mellon University’s Materials Science and Engineering and
Biomedical Engineering Department [21]. Their project is
known as FRESH, which stands for Freeform Reversible
Embedding of Suspended Hydrogels, and uses microgel to
support the prosthetic organ during construction but at
completion, the gel is melted away [21]. This method is meant
to eliminate the need for the rigid frames that are generally
used to bear the weight of the organ. Three-dimensional
bioprinters possess a great potential for sharing data files
between doctors and laboratories if the printers are
standardized to read STL files [20]. The ideal bioprinter offers
high resolution, efficient output, the ability to contain and
dispense a variety of bioinks, affordability, ease of use, and
6
Daniel Chu
Abigail Pinto
line. Bioprinting from a production viewpoint is a sustainable
field because of its opportunities for improvement in terms of
materials and process. Yet, like any other case of
groundbreaking technology, bioprinting organs raises ethical
concerns about its potential impact.
enhancements pose the question of eligibility to participate in
professional sports, such the Olympics [22].
As previously mentioned, bioprinters have the ability to
save the lives of thousands. At the same time, the technology
can be considered as a matter of interfering with nature and
prolonging life farther than we already have with modern
medicine. Before bioprinting, patients, such as the elderly,
would likely be ineligible for a high place on the transplant
list due to the small supply of viable organs. Bioprinters
provide an essentially endless supply of organs so anyone in
need could potentially receive them [22]. With the capability
of replacing failing parts of one’s body, immortality could
become achievable, but that may not be a positive result in
every situation. Unjust leaders could live in corrupt control
perpetually. The unnatural extension of human lives could
add to the problem of overpopulation. Overpopulation is
already a concern when considering available resources as
well as human influence on the natural environment [22].
Many of these ethical concerns do not currently have a clear
answer as bioprinting has not yet developed enough. While
these concerns should not be ignored, the potential benefits of
bioprinting’s success seems too advantageous to abandon.
ETHICAL CONCERNS
With the vast possibilities that come with such an
advanced technology, a series of ethical questions arise. At
the moment, bioprinting is too expensive to be considered
practical. If the capability exists to give every sick child the
exact organ they require, there is concern that low-income
families may be unable to pay. Depending on adjusted
healthcare regulations, the government, and essentially the
taxpayers, may be left to adopt the financial responsibility. If
aid is not offered to those who cannot afford such a procedure,
only the wealthy will be able to experience the benefits of
bioprinting. The social gap between the upper and lower
classes may become the gap between the healthy and sick
[22].
On the other hand, compared to traditional transplants
which are already expensive, bioprinting may actually reduce
the cost of receiving a new organ once the technology is
further developed. Currently, bioprinting as a whole is
expensive due to early development, but cheaper methods are
prevailing, as shown by the team at Carnegie Mellon
University [21]. Once modified, an ideal bioprinter may
function at minimal resources and therefore lower costs.
While the concern about some patients being unable to afford
the procedure is not invalid, once bioprinters become
successful, competition between companies may drive prices
down. In this case, it may be that bioprinters will enable
medical care to be more evenly distributed to the masses at an
affordable cost for everyone [23].
As with all emerging medical implants and devices,
there must be extensive testing to ensure the safety of the
product. When developing a new drug, scientists perform
multiple trials with hundreds of people in order to establish
requirements and regulations before mass distribution.
However, with bioprinting organs being specific to the
individual patient, it is difficult to test the organs for safety.
Bioprinted organs being created specific in size, shape, and
even chemical makeup means that each organ is unique,
making it hard to regulate and test to ensure quality [23].
With artificial body parts comes the idea of utilizing the
technology for the enhancement of the individual. In the
future, bioprinted muscles or a new heart could make a person
faster and more resilient to fatigue. Artificial lungs could be
designed to increase capacity to hold breath or become less
winded, leading to greater endurance. These artificial organs
could lead to an entirely new arms race of who can create the
greatest super soldier [23]. While bioprinting should be
available for someone whose life depends on a replacement
organ, there will undoubtedly be people who will attempt to
pay for an improved organ. These artificial organ
CONCLUSION
The first successful kidney transplant was between two
identical twins in 1954 [3]. Organ transplant technology has
significantly evolved since then and bioprinting’s potential
for the future holds much promise. Compared to traditional
transplants that involve a donor, bioprinting offers a solution
without relying on another person’s health, which benefits
both parties without negatively affecting either. Among the
various types of bioprinting, ink-based methods are the most
likely to be successful, namely the inkjet bioprinters.
Although bioprinting is temporarily hindered by the current
quality of the biomaterials and bioprinters and their associated
costs, research advancements suggest that bioprinting organs
will soon be a feasible accomplishment.
The process to print a healthy functional organ, identical
to its original, has no foreseeable expiration date and will not
become obsolete for a decent amount of time. There are few
other technologies that can offer a better solution to organ
repair and replacement. With lasting demand and no sign of
any competing processes, bioprinting is expected to continue
to prevail and thrive. The demand for healthy organs will not
decrease but instead increase as the population continues to
grow. Humans naturally age and everyone’s bodies
eventually fail, but 3D printing could consistently provide an
economical solution to those health issues. 3D printing organs
may lead to other medical improvements based on
bioprinting, such as prosthetic limbs with more organic
aspects. The process of bioprinting functional organisms also
opens possibilities into other fields besides the medical field,
such as botany or zoology. A new economic industry presents
itself as the bioprinting technology continues to develop,
becomes commercialized, and turns profit. 3D printing has
7
Daniel Chu
Abigail Pinto
[10] “Organ Donation and Transplantation Statistics.”
National Kidney Foundation. 2016. Accessed 3.1.2017.
https://www.kidney.org/news/newsroom/factsheets/OrganDonation-and-Transplantation-Stats
[11] S. Murphy, A. Atala. “3D Bioprinting of Tissues and
Organs.” Nature Biotechnology. 8.5.2014. Accessed
3.1.2017.
http://www.nature.com/nbt/journal/v32/n8/abs/nbt.2958.htm
l
[12] K. Hölzl, S. Lin, L. Tytgat, S Van Vliergerghe, L. Gu, A.
Ovsianikov. “Bioink Properties Before, During and After 3D
Bioprinting.” IOP Science. 9.23.2016. Accessed 3.1.2017.
http://iopscience.iop.org/article/10.1088/17585090/8/3/032002
[13] M. Davenport. “Print Your Heart Out.” Chemical &
Engineering News. 3.9.2015. Accessed 3.2.2017.
http://cen.acs.org/articles/93/i10/Print-Heart.html
[14] R. Jose, M. Rodriguez, T. Dixon, F. Omenetto, D.
Kaplan. “Evolution of Bioinks and Additive Manufacturing
Technologies of 3D Bioprinting.” ACS Biomaterials: Science
&
Engineering.
3.25.2016.
Accessed
2.28.2017.
http://pubs.acs.org/doi/abs/10.1021/acsbiomaterials.6b00088
[15] F. Zohora, A. Azim. “Inkjet Printing: An Emerging
Technology for 3D Tissue or Organ Printing.” European
Scientific
Journal.
10-2014.
Accessed
3.1.2017.
eujournal.org/index.php/esj/article/download/4464/4274
[16] F. Rengier, A. Mehndiratta, H. von Tengg-Kobligk. “3D
Printing Based on Imaging Data: Review of Medical
Applications.” International Journal of Computer Assisted
Radiology and Surgery. 7.20.10. Accessed 1.11.2017.
http://link.springer.com/article/10.1007/s11548-010-0476-x
[17] “Inkjet Bioprinter.” Labromancy. 2017. Accessed
3.2.2017.
http://www.labromancy.com/product/inkjetbioprinter/
[18] T. Billiet, E. Gevaert, T. De Schryver, M. Cornelissen, P.
Dubruel. “The 3D Printing of Gelatin Methacrylamide CellLaden Tissue-Engineered Constructs with High Cell
Viability.” Science Direct. 1.2014. Accessed 2.15.2017.
http://www.sciencedirect.com/science/article/pii/S01429612
13011782
[19] “Printing a Bit of Me.” The Economist. 3.8.2014.
Accessed
3.2.2017.
http://www.economist.com/news/technologyquarterly/21598322-bioprinting-building-living-tissue-3dprinter-becoming-new-business
[20] B. Gross, J. Erkal, S. Lockwood, C. Chen, D. Spence.
“Evaluation of 3D Printing and Its Potential Impact on
Biotechnology and the Chemical Sciences.” Analytical
Chemistry.
2014.
Accessed
1.9.2017.
http://pubs.acs.org/doi/full/10.1021/ac403397r
[21] Balbright. “Low-Cost Human Organ Printing.” Rapid
Ready
Tech.
11.16.2015.
Accessed
2.9.2017
http://www.rapidreadytech.com/2015/11/low-cost-humanorgan-printing/
[22] M. Varkey, A. Atala. “Organ Bioprinting: A Closer Look
at Ethics and Policies.” Heinonline. 5.2.2015. Accessed
the potential to be inexpensive but also highly effective.
Although it is not fully developed right now, bioprinting will
not only be a sustainable technology but will also sustain
people and their lifestyles. Bioprinting directly saves lives
with more efficiency than any other options. Its sustainability
lies in the fact that bioprinting could eventually provide
replicas that are almost indistinguishable in form and function
from natural organs.
With the advent of bioprinters, the economy and
manufacturing industry will adapt with the change in
importance of production lines and supply chains. Like with
all types of technology, the related risks are vital for
consideration. However, bioprinting’s potential to save lives
and revolutionize the economy, the manufacturing industry,
and the medical world suggests that such an advancement
would be beneficial to society as a whole and a technology
worth pursuing.
SOURCES
[1] “Data.” United Network for Organ Sharing. 2017.
Accessed 1.11.2017. https://www.unos.org/
[2] I. Petrick, T. Simpson. “3D Printing Disrupts
Manufacturing: How Economies of One Create New Rules of
Competition”.
2013.
Accessed
1.8.2017. http://www.tandfonline.com/doi/pdf/10.5437/089
56308X5606193
[3] A. Dababneh, I. Ozbolat. “Bioprinting Technology: A
Current State-of-the-Art Review.” The American Society of
Mechanical Engineers. 10.24.2014. Accessed 1.26.2017
http://manufacturingscience.asmedigitalcollection.asme.org/
article.aspx?articleid=1903284
[4] B. Thompson. “How 3D Printing Will Impact the
Manufacturing
Industry.”
Manufacturing
Business
Technology.
1-2016.
Accessed
1.
8.
2017.
http://www.mbtmag.com/article/2016/01/how-3d-printingwill-impact-manufacturing-industry
[5] C. Ventola. “Medical Applications for 3-D Printing:
Current and Projected uses”. P&T Community. 10.10.2014.
Accessed
3.2.2017.
https://www.ptcommunity.com/system/files/pdf/ptj3910704.
pdf
[6] W. Harris. “How 3-D Bioprinting Works.” How Stuff
Works
Health.
12.13.2013.
Accessed
1.23.2017.
http://health.howstuffworks.com/medicine/moderntechnology/3-d-bioprinting1.htm
[7] A. Atala. “Printing a Human Kidney.” Ted. 3.2011.
Accessed
1.20.2017.
https://www.ted.com/talks/anthony_atala_printing_a_human
_kidney
[8] “Top 9 Medical Applications for 3D Printing - Epic List.”
On 3D Printing. 8.30.2013. Accessed 3.2.2017.
http://on3dprinting.com/tag/medical/
[9] L. Martin. “Transplant Rejection.” Medline Plus.
4.30.2015.
Accessed
3.1.2017.
https://medlineplus.gov/ency/article/000815.htm
8
Daniel Chu
Abigail Pinto
3.3.2017.
http://heinonline.org/HOL/Page?handle=hein.journals/wfjlap
o5&div=15&g_sent=1&collection=journals#
[23] S. Dodds.”3D printing raises ethical issues in medicine.”
ABC
Science.
2.11.2015.
Accessed
3.2.2017.
http://www.abc.net.au/science/articles/2015/02/11/4161675.
htm
ADDITIONAL SOURCES
“Print for Medical Products and Test Procedures.” Javelin.
2016. Accessed 1.11.2017. http://www.javelin-tech.com/3dprinter/industry/medical/
“3D Printing.” Senesciencia. 2017. Accessed 1.10.2017
http://www.ub.edu/senesciencia/noticia/3d-printing/
ACKNOWLEDGEMENTS
We would like to thank our peer advisor, Madeline
Spiegel, for her advice and guidance. The University of
Pittsburgh library staff also provided numerous resources
which were vital during the research process. Lastly, thank
you to our writing instructor, Janine Carlock, for the
constructive criticism and direction.
9