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THE FUTURE OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE:
STEM CELL RESEARCH
Casey Tompkins-Rhoades (cct8@pitt.edu)
development, but have recently been successful in stem cell
therapies for heart disease and leukemia [2].
The sources of stem cells include embryos,
embryonic germ tissue, and adult tissue. The differences in
these sources are the stages of tissue development:
embryonic cells come from a very early embryo in the
blastocyst stage, germ cells are taken from fetal tissue
collected after the embryo has developed, and adult stem
cells are taken from fully developed mature tissues [2].
While research using mature tissue stem cells has yielded
great progress for regenerative medicine thus far, there is so
much more potential in this field, but the lack of federal
funding for the expansion to embryonic cell research has
hindered development.
AN INTRODUCTION TO THE STEM CELL
DEBATE
The debate over stem cell research involves many
groups including antiabortion activists, government officials,
religious communities, and scientists. The field of stem cell
research is swamped in controversy because of one source of
cell development: embryos.
The opposition to embryonic stem cell research
argues that these types of stem cells have yielded no
progress, destroy potential life, and cause scientists to fall
into the “playing God” mentality [1]. Because of such strong
opposition, Congress has been hesitant to distribute federal
funding for stem cell research--research that has the
potential to transform the treatment of degenerative diseases
and has already changed the way scientists look at tissue
engineering.
As an undergraduate engineering student, this
debate provides a real world example of what many
engineers fight for everyday in their fields: a progression of
science amidst a society obsessed with a different kind of
science, the political kind. According to the codes of ethics
held by both the National Society of Professional Engineers
and the Biomedical Engineers Society, engineers have a
responsibility to the public and to their profession to act
impartially and avoid letting bias influence their work.
How opinions about stem cell research and tissue
engineering have developed over the last ten years and
where they will go from here is important for future
engineers like me to research, because not only will these
issues still be relevant as we enter our fields, but they also
serve to teach us the “attitude” of an engineer. An attitude
that, according to the College of Engineering at the
University of Michigan, Ann Arbor, is critical to a
comprehensive engineering education. What actually defines
this attitude and how it is incorporated into our engineering
education could be the difference between a positive future
for the development of stem cell research and a halting of
progress in the field of tissue engineering and science as a
whole.
A TIMELINE OF STEM CELL RESEARCH
In modern day America, stem cell research has
sparked public debate and controversy, but most Americans,
including government officials and religious leaders, don’t
know the history and progression of stem cell therapies.
Before we can analyze the ethical arguments surrounding
stem cell research, we have to look at how the research has
evolved in the last century.
Stem cells were first discovered in the mid 1800’s
as cells that had the ability to generate new cells. It wasn’t
until the 1900’s that researchers discovered that certain types
of these cells could produce blood cells. In 1968, the first
bone marrow transplant was performed, and in the late
1970’s, stem cells were discovered in human cord blood.
The first embryonic stem cell lines were developed from
mammals in the 80’s but at the turn of the century, scientists
discovered that by manipulating the cells, bone marrow cells
could generate other types of cells such as those in the liver
and nerves. The scientific community was launched into an
era of regenerative medical breakthroughs [3].
TISSUE ENGINEERING AND STEM
CELL DEVELOPMENT
Tissue engineering plays a major role in
regenerative medicine, and the term refers to the
replacement, repair, or regeneration of tissues, usually
outside of the body. Doctors and engineers work together to
create a culture of cells that can be transplanted back into a
patient. Cells are usually taken from the host or host organ,
but in a growing number of cases, there aren’t enough
healthy cells to create a full culture. Stem cells provide a
source which can be easily accessed and applied to many
WHAT EXACTLY ARE STEM CELLS?
Stem cells are broken up into three categories
separated by cell functions. Totipotent cells from embryos
each have the ability to grow into an organism. Pluripotent
cells can generate over 200 different types of cells.
Multipotent cells, which come from fetal tissue, cord blood,
and mature tissue, have a much more limited range of
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Casey Tompkins-Rhoades
cases, but even though recent discoveries have showed a lot
of potential for this field, there is still a lot of research to be
done. An increase in federal funding for stem cell research
would have a direct impact on the development of cell-based
therapies utilized in regenerative medicine [4].
The stage of development from which embryonic
stem cells are harvested is the blastocyst stage, which is a
cluster of cells that have not differentiated into distinct
organs or tissues. Antiabortion activists argue that scientists
will have the opportunity to destroy human embryos when,
in reality, these embryos are fertilized outside of the body
and could not survive without the presence of a womb. Once
stem cell lines are created they are considered “immortal” in
the sense that no new embryos need be destroyed to
maintain these lines. Putting restrictions on embryonic stem
cell research would waste this already established resource
[6].
In that same vein, in vitro fertilization, a growing
industry utilized to increase the probability of pregnancy,
creates thousands of embryos a year in the hopes that one or
a few may successfully implant for each couple. The rest of
the embryos are destroyed, but with expanded funding for
embryonic cell research, these embryos could prove a
valuable resource to the scientific community [6].
As a future bioengineer and possible future doctor,
I often listen for the current events in medical research and I
like learning about scientific breakthroughs, but after
watching my aunt suffer and pass away from Lou Gehrig’s
disease, also known as ALS, a degenerative disorder that
affects the nerves and the spinal cord, I am very passionate
about the future of tissue engineering and regenerative
medicine specifically. I believe that striving for cures for
diseases like Parkinson’s, diabetes, and ALS should not be
hindered by one group’s moral misgivings. Curing these
conditions is where the potential for life lies.
THE TRUTH ABOUT EMBRYONIC
STEM CELLS
Though there have not been many breakthroughs
solely associated with embryonic stem cells, these cells
specifically are the key to human biology. In other
mammals, embryonic stem cells have been harvested and
manipulated to create therapies that have been used to treat a
variety of conditions such as congenital heart disease. For
example, a small primate, a marmoset, recovered from a
paralyzing spinal cord injury in three weeks after being
treated with embryonic stem cells. Japanese researcher,
professor Hideyuki Okano of Tokyo's Keio University stated
that, "After six weeks, the animal had recovered to the level
where it was jumping around" [5]. Research teams like this
one are making an effort to translate these successes to
approved treatments for humans, but without an expansion
on federal funding here in the United States, resources for
this research are very limited.
There may be no approved embryonic stem cell
therapies for humans yet, but most diseases and defects are
caused by problems in the process of development from the
embryonic stage to mature tissue. Studying embryonic stem
cells can not only help doctors understand many of these
conditions, but also develop methods to treat and prevent
them [2].
The reason scientists have been pushing so hard for
a research expansion into embryonic stem cells is due to the
restrictive nature of mature adult stem cells. Though recently
adult stem cells have been found in some regions of the body
and its organs, known as “stem cell niches,” as well as
umbilical cord blood, there is a limited source of these cells
while embryonic cells can be grown and expanded almost
limitlessly. Adult stem cells also have a limited range of
development as many can only grow into a small array of
specialized cells. Embryonic stem cells provide researchers
with an abundant, flexible source to study and manipulate
[2].
Besides being easier to grow and isolate, embryonic
stem cells can easily generate thousands of offspring while
adult stem cells don’t divide nearly as rapidly and could
hinder opportunities for immediate treatments. Adult stem
cells are also unreliable for the treatment of genetic disorders
because they are full of DNA abnormalities from exposure
to things like sunlight and toxins [2].
STEM CELL RESEARCH: AN
ETHICAL ISSUE, NOT A MORAL ONE
Many people don’t realize the subtle yet important
difference between morals and ethics and often try to
influence public policy with their personal morals, but in
reality, public policy should be governed by an ethical
standard set up by society independent from any one
person’s or group’s religious or moral opinions.
If stem cell research and tissue engineering were
properly judged by the ethical canons established by the
National Society of Professional Engineers, the arguments
over this issue would seem trivial because tissue engineers,
many of whom are stem cell researchers and/or contribute to
this field, are obligated by these guidelines to “not be
influenced in their professional duties by conflicting
interests” [8]. To engineers, this debate is cut and dry.
Special interest groups have no place in the development of
humane research, but nonetheless the topic of embryonic
stem cell research is flooded with controversy stemming
from uneducated groups touting what they perceive to be
their moral obligations.
Tissue engineering, which falls under the field of
Biomedical Engineering, is governed by an additional code
THE POTENTIAL FOR LIFE
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Casey Tompkins-Rhoades
of ethics created by the Biomedical Engineers Society which
also encourages professionals to operate independent of the
influence of biased groups. Additionally, the BMES expects
engineers “entrusted with the responsibilities of training
others” to responsibly “keep training methods and content
free from inappropriate influence of special interests” which
not only enforces the canons established by the NSPE, but
also brings up another emerging issue: the competence of the
current engineering curriculum and how it is preparing
students to deal with issues such as the debate over
embryonic stem cell research [9].
At Pitt, the Swanson School of Engineering
encourages undergraduate students to research and develop
opinions on current engineering issues like this one, in order
to help us learn how to think like engineers. The College of
Engineering at the University of Michigan, Ann Arbor, takes
a different, yet effective approach at developing their
students into fully functional engineers by teaching what
they refer to as the “engineering attitude.” In a study done by
two students, Cristina Pomales-Garcia and Yili Liu,
undergraduates in the college of engineering were
questioned about their perception of the engineering
education offered at the University and ten out of the twelve
focus groups agreed that, along with the critical thinking,
teamwork, and communication skills they learned, they were
also taught a mindset defined by the ability to accept
mistakes, uphold an ethical standard, and possess an open
mind [10].
In my own personal experiences here at Pitt, I’d
have to agree that this “engineering attitude” is included in
our curriculum through homework like our Engineering
analysis projects that teach teamwork, but also encourage the
honesty and accountability of each group member. We were
also required to use this attitude when researching for our
current engineering issue assignment, because we had to
look at the assignment from the standpoint of an engineer
rather than just another reader.
The College of Engineering at the University of
Michigan, Ann Arbor could incorporate a project like this
into their curriculum to reaffirm what they are already
teaching their students to develop: an outlook based on a
professional opinion rather than just a moral one.
continuing to comprehensively educate their students.
Universities must encourage students to develop ethically
professional viewpoints so that science, a historically
controversial area of study in general, can progress without
the influence of special interest groups.
Though these various groups seem to dominate
Washington and what we know as the American political
process today, advancements in stem cell research have
revolutionized tissue engineering and treatment possibilities
for severely crippling and sometimes fatal diseases. In 2001,
former President George W. Bush enacted a policy which
restricted the federal funding of stem cell research to the
development of stem cell lines before August 9th, 2001. Even
though this was a restrictive policy, the NIH provided $294
million for embryonic stem cell research under President
Bush’s administration [7]. Since President Obama issued his
Executive Order, Removing Barriers on Responsible
Scientific Research Involving Human Stem Cells, on March
9th, 2009, the NIH has overseen the creation of guidelines
and approvals for stem cell research in an attempt to expand
and support this field of regenerative medicine. Currently,
stem cell research is growing thanks to public and private
funding, with some states even taking initiative like the New
Jersey Stem Cell Research Program and the California
Institute for Regenerative Medicine, which provide grants
and loans to scientists [2]. While stem cell research grows,
so can our hope for cures and breakthroughs in the future of
regenerative medicine.
REFERENCES
[1] (2010). “Top 10 Arguments Against Stem Cell
Research.” Health Articles 101. (Online Article).
http://www.healtharticles101.com/top-10-argumentsagainst-stem-cell-research/
[2] (2012). “Stem Cell Site”. National Institutes of
Health, U.S. Department of Health and Human Services.
(Online
Article).
http://stemcells.nih.gov/StemCells/Templates/StemCellCont
entPage.aspx?NRMODE=Published
[3] Prakash, Rishi. (2012) "Stem Cell Research History &
Development: A Brief Overview." Bright Hub. (Online
Article).
<http://www.brighthub.com/science/genetics/articles/30772.
aspx>.
[4] Li, Song. (2011). Stem Cell and Tissue Engineering.
River Edge, NJ: World Scientific and Imperial College
Press. (Print Book). pp. 1-8
[5] (Dec. 8, 2010). "Stem Cell Therapy Helps Monkey Jump
Again." Discovery
News.
(Online
Article).
http://news.discovery.com/animals/stem-cells-paralyzedmonkey.html
[6] Douglas, Thomas, and Julian Savulescu. (Apr. 2012).
"Destroying Unwanted Embryos in Research. Talking Point
CONCLUSION: LET’S FUND THE
FUTURE
In a world that’s becoming more and more focused
on the newest science and technology, the perspective of
those researching and developing these advancements
becomes crucial. Without open minded, ethically-focused
engineers, stem cell research definitely would not have
survived the controversy surrounding it. With that said, the
engineering schools across the nation still hold the
responsibility of assigning research on current ethical issues,
discussing ethical gray areas in the field of science, and
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Casey Tompkins-Rhoades
on Morality and Human Embryo Research." US Library of
Medicine National Institutes of Health. (Online Article).
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672894/
[7] The Witherspoon Council on Ethics and the Integrity of
Science, "The Stem Cell Debates: Lessons for Science and
Politics," The New Atlantis, Number 34, Winter 2012, pp. 960.
(Online
Article)
http://www.thenewatlantis.com/publications/the-stem-celldebates-lessons-for-science-and-politics
[8] "NSPE Code of Ethics for Engineers." NSPE Code of Ethics
for Engineers. N.p., n.d. Web. 28 Oct. 2012.
<http://www.nspe.org/Ethics/CodeofEthics/index.html>.
[9] "BMES | Code of Ethics." BMES | Code of Ethics. N.p., n.d.
Web.
28
Oct.
2012.
<http://www.bmes.org/aws/BMES/pt/sp/ethics>.
[10] Pomales-Garcia, Cristina, and Yili Liu. "Excellence in
Engineering Education: Views of Undergraduate Engineering
Students." Journal of Engineering Education, n.d. Web. 28 Oct.
2012.
<http://www.engr.wisc.edu/services/elc/studentswant.pdf>.
ACKNOWLEDGEMENTS
Thanks to the writing instructors and librarians who came to
the Engineering Analysis classes. A special thanks to Soyo
Awosika-Olumo who motivated me to finish this paper all
weekend.
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