Robin Thomas
Disclaimer—This paper partially fulfills a writing requirement for first year 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 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 engineering students at the University of Pittsburgh Swanson School of Engineering, the user does so at his or her own risk.
ORGAN TRANSPLANTS AND STEM CELL RESEARCH
Robin Thomas ()
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Robin Thomas
ORGAN TRANSPLANTS: WHY AREN’T THERE MORE?
As the world’s best scientists discover more cures, vaccines, and solutions to diseases, it seems as if every disease multiplies tenfold. Can you imagine the amount of viruses, bacteria, harmful chemicals, and cells that have yet to adaptor that we have yet to discover? Many people are victim to these kinds of illnesses—cancer, heart disease or attacks, liver and kidney failure, etc.—that cause organ failure.
According to the U.S. Government Information on Organ Donation and Transplantation, more than 119,000 men, women, and children are on the national organ transplant waiting list [1]. Of those 119,000 people, 22 pass away every day[1]. The worst part is that because of these diseases that can change and adapt and resist, the waiting list is growing [1]. Obviously citizens can help by registering to be organ donors, but only 48% of U.S. adults can sign up as donors, even if 95% support it [1]. These statistics show the importance of organ donation but also highlight the problem. If people do not become organ donors, more patients who need transplants will not get the organs they need.
Recently, scientists began studying the properties and uses of stem cells. Research regarding stem cells as supplemental regenerative cells in the damaged areas of the organ has increased over the last few years. More importantly, investigation in using stem cells for organ transplants has begun to spark interests in stem cell research. It seems that stem cells could eventually end the need for organ donors, a breakthrough that could help the 119,000 people still waiting for organs. Stem cell researchers have successfully grown miniature hearts, stomachs, livers, kidneys, and other organs using mice stem cells. Imagine the substantially reduced number of patients who needed organs if, using stem cells, they could have a completely new organ, without needing to wait for an organ donor.
STEM CELL RESEARCH WITH ORGAN TRANSPLANTS
What are Stem Cells?
Stem cells are undifferentiated cells with the potential to become one of a variety of cell types, showing promise in the treatment of many diseases. Basically, these cells can be introduced to an area of the body to act as that body part’s regenerating cells. For example, if a person has a heart attack, stem cells can be introduced to the heart. The cells will “migrate to the site of the damage, proliferate, and differentiate into new cardiomyocytes, or heart muscle cells,” according to a stem cell research article by Courtney Farrell [2].As mentioned before, stem cells are showing promise as the cure for many illnesses that are becoming more prominent in the population.
Organs Made by Stem Cells
In the past few years, scientists have used stem cells to create new organs. According to the National Institutes of Health, before 2012-2013, the use of stem cells was as an “internal repair system, dividing essentially without limit to replenish other cells as long as the person is still alive” [3]. This means that stem cells were injected into the body to replenish the damaged cells. According to EuroStemCell, scientists all over the world have engineered stem cells into tiny organs that can be used for studying development, disease, and testing of toxicity or new treatments [4]. In the future, researchers predict that these mini organs will be able to replace research using animals as well [4]. In addition to using the produced organs for research but regarding the problem of organ transplant patients needing organs, what if scientists were to grow human-sized organs?
MAKING ORGANS AND THE PROBLEM
Making Organs
Many universities, research facilities, hospitals and laboratories are exploring the phenomena of stem cells. As mentioned before, scientists have already begun making tiny organs for research purposes: the MRC Centre for Regenerative Medicine regrew livers in mice, the Center for Regenerative Medicine transplanted working lab-grown kidneys into rats, the Cincinnati Children’s Hospital Medical Center grew three-dimensional stomachs, etc [4]. In addition, an interesting fact is that researchers from the University of Pittsburgh have grown miniature human hearts from mice hearts [4]!
An example of my hypothesis that organs grown from stem cells is becoming a reality. One of the hospitals that has successfully grown a beating human heart is the Massachusetts General Hospital. Teamed up with Harvard Medical School, the hospital combined two things: 3D printers and heart tissue. 3D printers can manufacture 3D heart segments which can be the “scaffold” for heart tissue to be grown on. As mentioned previously, these hearts will be used for researching development and disease to potentially eliminate animal testing. In addition to this research, these hearts, once grown to an actual size, could be implanted into a patient suffering from a degenerative heart disease. If they were on the wait list, they may have to wait months, even years, for a new heart.
The Problem with Organs Grown from Stem Cells
The problem with using organs from stem cells is the chance that the patient’s body will reject the new organ [5]. This occurs even with organ donors. Basically, the patient’s immune system may treat the new organ as a threat to the body, so it will try and attack it to destroy it [5]. That is probably why there are few experiments with growing human sized organs. With all the money and resources it would take to produce a human organ, scientists would have to be absolutely positive that the organ would be accepted into the body, the organ would perform the necessary functions, and that the patient was willing to have the organ possibly fail. This is also why organ donors are still the best option for organ transplants. Organ donations are still time-dependent, so manufacturing new organs would still be an effective solution to the problem, if researchers could figure out how to trick the body into accepting the organ.
Challenges with Stem Cells and Applying These Challenges to Stem Cell Organs
There are problems with stem cell usage in general as well. Instead of making a heart using stem cells, a heart disease could be treated by sending stem cells to the damaged portion of the heart. It seems that this method is not as effective as scientists would like it to be. In the opinion of Jane Hoover-Plow and Yanging Gong, there are three challenges to improve the usage of stem cells: “improved identification, recruitment, and expansion of stem cells, identification of mobilizing and homing agents that increase recruitment, and development of strategies to improve stem cell survival” [6]. The first challenge has to do with stem cell being undifferentiated. If scientists were able to improve the specialization of the stem cells, they would be more accepted by the body [6]. In the example with the heart, the stem cells would have to be specialized into heart muscle cells. The second challenge regards the position of the stem cells once they are in the body. Researchers use markers and trackers to know the general location of the stem cells, but there are normally too many markers needed [6]. The end goal to define the position of the stem cells is hard to reach if it is impossible to track them. Being able to improve the “homing agents” will help to find the stem cells and see the process at the damaged site. The last challenge is the most important one to overcome. As the stem cells migrate through the body, it is easy for there to be a loss of supporting cells [6]. Futhermore, it is extremely likely for the stem cells to die before they even reach the damaged source. These are the most general challenges with using stem cells, but they are the reasons why scientists have to use stem cells wisely. Using stem cells only to find out that they will not specialize, they will not be able to be tracked, or they will not live to complete the experiment is too much of a costly risk.
These challenges, however, can be applied to using organs made from stem cells; these challenges only apply if the body accepts the organ. The stem cells used in the organs should be specialized to the tissue of the organ. It will be easy to track the stem cells because the entire organ will be composed of the cells. The hardest challenge to overcome will be to ensure that the organ functions correctly and works well with the body.
WHY ORGAN TRANSPLANTS ARE IMPORTANT TO ME
I chose this engineering problem to hypothesize a solution because it relates to my extended family. My cousin had a heart disease called Coronary Heart Disease. This disease plagues over 7 million people in the United States alone [7]. My cousin’s coronary arteries were narrowed with plaque, causing the blood and oxygen flow to the heart to slow down [7]. He was one on a wait list for a heart for almost a year, even though his illness was degenerative. He passed away before he could have a transplanted heart. The worst part of the situation was that he was only in his twenties. This is why I think it is so important to have organs available to everyone who needs new ones. The amount of damaging diseases out in the world is alarming, but the mortality rate due to them is something that can decrease. If scientists can make tiny organs for research, they can eventually make life-sized organs. These could be the solution to lack of organ donors. If my cousin were alive, I am sure he, and his family, would have been excited to know that a heart grown from stem cells could be in the near future.
NEW ORGANS FOR EVERYONE
In conclusion, organs made from stem cells could potentially solve the problem of organ transplant patients. Without organ donors, these patients will be on the wait list for too long. Stem cell research is a new field, but utilizing its potential will help to overcome mortality rate of patients with damaged organs. Using stem cells to generate organs is already possible, but those organs are used for research purposes. If they were to be grown life size, they could be implanted into transplant patients. The main reason why this is not a viable option right now is because scientists do not know how to allow a patient’s body to accept the organ. Other challenges with stem cell therapy in general are the lack of specialization, the tracking of the cells, and the survival rate of the cells. Applying improvements to these challenges will help stem cell research overall, but more importantly will pave the course toward stem cell organs made for humans. This is such an important topic for society, but it is also important for me because of my cousin. If stem cells organs were an option for transplant patients, maybe my cousin would be alive right now. This is why stem cell organs for humans are a solution to organ transplant patients and the lack of organ donors.
SOURCES
[1] “Organ Donation Statistics.” U.S. Government Information on Organ Donation and Transplantation. 3.31.15. Accessed 10.29.16.
[2]C. Farrell. R. Carson-Dewitt. “Stem Cell Research: An Overview.” Points of View Reference Center. 3.1.16. Accessed 10.29.16.
[3] “Stem Cell Basics.” National Institutes of Health.Accessed 10.29.16.
[4] “Eight tiny organs grown by scientists.” EuroStemCell. 7.31.15. Accessed 10.29.16.
[5]R. Andrews. “Beating Human Hearts Grown In Laboratory Using Stem Cells.” IFL Science. 03.21.16. Accessed 10.29.16
[6] J. Hoover-Plow. Y. Gong. “Challenges for heart disease stem cell therapy.” U.S. National Library of Medicine National Institutes of Health. 2.17.12. Accessed 10.29.16.
[7] “What is Coronary Heart Disease?.” National Heart, Lung, and Blood Institute. 6.22.16. Accessed 10.29.16.
ACKNOWLEDGMENTS
First, I would like to thank my father for showing my articles about stem cell research that sparked my interest in learning more. I would like to thank my friend Rachel for helping to find a topic to discuss and for encouraging me to work on my essay. I would like to thank Natalie and Jon for helping me in engineering analysis in general.I would like to thank Sam for being a wonderful cousin, rest in peace.
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