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Budny Tues/Thurs 4:00 L13 ETHICS AND THE ENGINEER: MAKING AN ETHICAL DECISION ABOUT STEM CELLS BASED OF OFF CURRENT ETHICAL CODES AND GUIDELINES Gabrielle Schantz ([email protected]) INTRODUCTION: ENGINEERING CODES OF ETHICS AND THE RESEARCH DESIGN PROCESS Bioengineering uses basic engineering principles and applies them to the biological world. This creates the need to approach ethically-charged situations with respect to current engineering ethics and medical ethics. To do so, I must use the National Society of Professional Engineers (NSPE) Code of Ethics for Engineers and the Biomedical Engineering Society (BMES) Code of Ethics. These codes of ethics are a major source of ethical guidance for professional bioengineers. The NSPE Code of Ethics for Engineers involves the obligations that engineers must follow to truthfully and legally engage in research and design settings. Furthermore, the BMES Code of Ethics includes values outlined by the NSPE Code of Ethics along with medical research ethics and training ethics of bioengineering. Throughout this essay, I will determine the effectiveness of these codes of ethics as well as how they will help me in facing the ethically-charged issue of using stem cells in an artificial skin substitute for burn patients. Additionally, I will have to utilize sources about engineering ethics and other necessary resources that will help me come to a decision on using embryonic stem cells to create an artificial skin graft for use on severely burned patients. SETTING THE SCENE: STEM CELL RESEARCH AND SKIN TISSUE ENGINEERING Structure of Skin and Types of Burns A basic understanding of the structure of skin and the types of burns is needed to understand my proposed research of artificial skin materials. To start off, the skin is composed of two major layers called the epidermis and the dermis. The epidermis is the outer layer of skin that protects the inside of the body from the environment, and the inner-layer called the dermis allows the skin to be flexible [1]. The amount of damage that occurs to these layers of skin determines the category into which a burn falls. These categories are epidermal burns, superficial partial-thickness burns, deep partial-thickness burns, and full-thickness burns. Only deep partial-thickness and full-thickness burns are relevant to my proposed design because they require the use of skin grafts in their treatment. Deep partial-thickness burns occur when University of Pittsburgh, Swanson School of Engineering 1 2013-10-29 the epidermis and a majority of the dermis are damaged and very few regenerative cells remain, whereas full-thickness burns occur when both the epidermis and dermis are completely destroyed [2]. The Problem With Current Treatments and the Solution For my research design, I will focus on the treatment of deep-partial thickness and full-thickness burns. These can be treated with dermo-epidermal skin substitutes, which are the most advanced bioengineered skin material due to the fact that they contain both an epidermal and dermal component. [2]. However, all artificial skin substitutes tend to have the same major problem of immunogenicity (the ability to cause an immune response). The immune system reacts to the artificial skin grafts just as it would towards an infection. The immune response starts out when donor dendritic cells (DCs) migrate from the graft into the lymph nodes of the patient. Here, the T-cells become activated and reproduce to secrete inflammatory cytokines, which travel back to the graft and kill the donor skin cells [3]. In order to decrease the amount of immunogenicity of the artificial skin grafts, I am considering using stem cells because they typically are not rejected by the body’s. The design will consist of a dermo-epidermal skin substitute that combines a sheet of epidermal stem cells with a dermal stem cell scaffold because it allows for specific stem cell microenvironments to influence stem cell function through biochemical and physical cues, which means that the cells will train themselves to become functioning skin cells [4]. However, the usage of stem cells creates the ethicallycharged scenario of choosing between embryonic stem cells and adult stem cells for use in the design. In order to determine whether or not I will use embryonic stem cells in my research, I must follow the engineering codes of ethics, while considering input about the codes and other resources specific to stem cell research. THE CODES AND THEIR APPLICATION TO THE SITUATION As a future engineer, there are codes that have been set in place to help me make rational and ethical decisions. However, not all of the canons and codes are applicable to my research scenario and many of them seem to be ineffective in guiding me in the decision making process. They are ineffective because they mostly deal with Gabrielle Schantz confidentiality between employers, clients, and engineers. However, two major canons of the NSPE Code of Ethics for Engineers apply to my scenario. These are to “hold paramount the safety, health, and welfare of the public,” and to, “conduct [myself] honorably, responsibly, ethically, and lawfully so as to enhance the honor, reputation, and usefulness of the profession” [5]. Unfortunately, these two canons are unclear and vague as to what they actually mean. I could interpret them as saying do what is necessary to make an artificial skin material that benefits the community as long as it is within legal regulations. I could also interpret them as stating that I determine what is ethical while creating a safe and effective product for the community. The ability to freely interpret the codes makes it hard to understand what my specific obligations are. Thankfully, there are societies that are more disciplinefocused, such as the Biomedical Engineering Society (BMES) Code of Ethics. The BMES Code of Ethics describes the obligations that bioengineers need to follow with respect to health care and research. According to these codes, bioengineers must, “regard responsibility toward and rights of patients, including those of confidentiality and privacy” [6]. Additionally, in their research bioengineers must, “comply fully with legal, ethical, institutional, governmental, and other applicable research guidelines, respecting the rights of and exercising the responsibilities to colleagues, human and animal subjects, and the scientific and general public” [6]. These codes tell me that I must follow all outlined guidelines for stem cell research, such as federal and state regulations. Furthermore, the BMES code of ethics force me to consider the implications and risks of stem usage on the test subjects and I will protect the privacy of the test subjects and the source of the stem cells. The BMES code of ethics is more effective than the NSPE code of ethics, but still lacks substantial direction and guidance. involves destroying a human embryonic cell in order to obtain the stem cells. This directly involves considering the sanctity of human life, which is why the topic is so controversial. Furthermore, the Nuremberg Code revolves around human experimentation and emphasizes voluntary and informed consent from test subjects, and the Declaration of Helsinki provides guidance on the topics of human test subjects, human materials like skin or tissue [7]. However, after consulting another source about tissueengineering ethics a major problem came to my attention. The problem lies in the fact that embryonic stem cell research causes the Hippocratic Oath and the Nuremburg Codes to conflict with one another. The protection of donor privacy (Hippocratic Oath) conflicts with the ideal of informed consent (Nuremberg Codes) because the intended use of the stem cells is not always specifically clear at the time of donation. This causes a need for some identifiable data to remain attached to the donated cells, which can inhibit the privacy of the patient [8]. Additionally, the testing of the engineered tissues can result in unclear informed consent due to the fact that most tissue-engineered products do not have clear long-term side effects after implantation [8]. To determine a possible solution to this ethical dilemma of informed consent, I looked into the National Institutes of Health (NIH) Guidelines on Human Stem Cell Research. The guidelines provide for informed consent from the donor(s) at the time of donation of excess embryos for clinical need. The consent is to come from the individual(s) who sought out the medical treatment because the individual(s) receiving the treatment are responsible for the creation of the embryos [9]. Additionally, I would be allowed to use stem cells that are already in the NIH Registry of stem cells. But, if I want to use cells outside the registry, then I must be able to provide all necessary documentation that clearly defines the source of the stem cells and that they were ethically obtained [9]. However according to the Declaration of Helsinki, if I use the stem cells from the NIH registry, which have identifiable human material, then I must seek the informed consent for its collection, storage, and/or reuse [10]. These guidelines are very specific in the necessary procedures and ethics involved with using embryonic stem cells, and have helped clarify the problems associated with obtaining the embryonic stem cells for use in my research design. INPUT ABOUT ENGINEERING ETHICS THAT SHAPED THE FINAL DECISION Even though the BMES code of ethics is more explicit than the NSPE code of ethics, I still need to consult outside sources that pertain to ethics within engineering. One article that helped me understand other codes and ethical obligations I may have to face was, “Ethics for Bioengineers” by Monique Frize within Synthesis Lectures on Biomedical Engineering. The article states that bioengineers involved in health care should also consult codes that are addressed towards medical physicians, such as the Hippocratic Oath, The Nuremberg Code, and the Declaration of Helsinki. The Hippocratic Oath provides moral and ethical obligations regarding, “the sanctity of human life, relief of suffering, [treating] the ill to the best of one’s ability, [and preserving] a patient’s privacy and confidentiality [7]. This applies to the decision on using embryonic stem cells because embryonic stem cell research INFORMATION ABOUT STEM CELL MORALITY AND ETHICS Following the codes of ethics in the ethical decision making process is important, but there are also ways of gathering ethical input that can be just as useful. For example, I was able to find a Gallup Poll about American opinions on the morality of embryonic stem cell research. According to the poll, 60% of Americans believed it was 2 Gabrielle Schantz morally acceptable to use stem cells derived from human embryos in medical research, 32% of Americans believed it to be morally wrong, and the remaining 10% either did not have an opinion or claimed the opinion depended on the situation. This approximately 60/30 split in opinion has remained relatively constant for the past four years [11]. This information suggests that the majority of Americans are in favor of medical research using human embryonic stem cells, which allows me to infer that the majority of Americans would also be in favor of my research scenario. Of course, this inference does not take into account their opinion on artificial skin-engineering, but is still valid from the view of that the research will be used for medicinal purposes. reproduce and divide longer. They are also safer than other types of stem cells, such as inducible pluripotent adult stem cells, which are adult stem cells that have been reprogrammed to act like embryonic stem cells. The inducible pluripotent stem cells have the same abilities as embryonic stem cells, but have a higher likelihood of uncontrolled growth [14]. The uncontrolled growth could potentially lead to malignant tumors, resulting in cancer. This makes using these stem cells potentially dangerous and life-threatening, especially since there is little long-term data on these reprogrammed cells. Another source of stem cells is bone marrow. Bone marrow derived stem cells could be a very useful and effective source of stem cells because bone marrow derived stem cells produce endothelium (skin) cells that lack immunogenicity. Their lack of immunogenicity could be seen when bone-marrow derived stem cells were added to lymphocytes (T-cells). The stem cells suppressed leukocyte (white blood cells responsible for riding the body of disease) proliferation by 50% [13]. Additionally, adipose derived stem cells have a major advantage over both embryonic stem cells and bone-marrow derived stem cells because they can be obtained from the discarded fat tissue of liposuction procedures. Adipose tissue can yield 100 to 1,000 times more cells per cubic centimeter than bone marrow tissue and also has immunogenicity that is almost 90% identical to that of bone-marrow [13]. This makes adipose derived stem cells easier to obtain and just as valuable as bone-marrow derived and embryonic stem cells. Each type of stem cell has their pros and cons, which are important in deciding whether any of them are more reasonable to use than embryonic stem cells in my design. BREAKING DOWN THE PROBLEM Additionally, the article, “Teaching Ethics to Engineers: Ethical Decision Making Parallels the Engineering Design Process,” written by Bridget Bero and Alana Kulhman of Northern Arizona University, was particularly helpful in outlining a procedure for breaking down an ethical problem to come to a clear concise decision. [12]. I followed the layout to break down the ethical problem of using embryonic stem cells in my research of the artificial skin graft. First, I had to list the relevant moral factors and dilemmas that I am faced with. These included such as using stem cells that have been obtained by destroying a human embryo and deciding whether the source of the cells is ethically just. Second, I had to consider the applicable moral theories, which included public approval of the usage of stem cells in research along with the benefits to using the stem cells (i.e. the reduced risk of immune system rejection in artificial skin grafts). Additionally, I had to take into account the ethical guidelines from the NSPE Codes of Ethics, the BMES Code of Ethics, and applicable medical codes of ethics, such as the Hippocratic Oath, The Nuremberg Codes, and the Declaration of Helsinki. The third step involved developing alternate courses of actions and their advantages and disadvantages, which in my case are alternatives to embryonic stem cells, which include bone-marrow derived stem cells and adipose (fat tissue) derived stem cells[13]. These alternatives and the advantages and disadvantages are presented in the subsequent section. The fourth and final step in process would be to determine the best course of action and justify the reason. THE FINAL COURSE OF ACTION After considering the different alternatives that could be used and the ethics involved with embryonic stem cells, I have decided to use only those embryonic stem cells that have been created in excess for medical purposes. I have decided this because embryonic stem cells are lacking in data that support how well they work in artificial skin substitutes and my goal is to determine the efficacy of embryonic stem cells to reduce immunogenicity. However, if they prove to be ineffective or equal to the effectiveness of other stem cells, I would immediately stop using the embryonic stem cells in my research because there would be no logical reason to continue using the embryonic stems if there is a more effective alternative. I was able to come to this conclusion despite lacking explicit guidance from the ethical codes set in place for me as a bioengineer and as an engineer in general. The challenges with the current codes that I had to overcome included the vagueness of the current codes of ethics for bioengineers and the lack of codes about research in the NSPE codes of ethics. In order to overcome this lack of guidance, I had to utilize other ethical codes and federal THE ADVANTAGES OF SPECIFIC STEM CELLS Human embryonic stem cells have some advantages over stem cells that come from an adult source because embryonic stem cells have the ability to differentiate into almost any type of cell (pluripotent) and the ability to 3 Gabrielle Schantz regulations, along with opinion polls to determine how ethical the use of embryonic stem cells would be. The challenges that I face are the main reason as to why I believe improvements need to be made to these codes that are open to a wide array of interpretation. http://www.nspe.org/resources/pdfs/Ethics/CodeofEthics/Co de-2007-July.pdf [6] (2004). “Code of Ethics.” Biomedical Engineering Society. (Online Publication). http://bmes.org/files/2004%20Approved%20%20Code%20o f%20Ethics(2).pdf [7] M. Frize. (2012). “Ethics for Bioengineers.” Synthesis Lectures on Biomedical Engineering, lecture #42, J. Enderle. Morgan & Claypool Publishers. (Electronic book). pp. 9-11. http://www.morganclaypool.com/doi/pdf/10.2200/S00393E D1V01Y201111BME042 [8] A.J.M. Oerlemas, M.E.C. van Hoek, E. van Leeuwen, S. van der Burg, W.J.M. Dekkers. (2012). “Towards a Richer Debate on Tissue Engineering: A Consideration on the Basis of NEST-Ethics.” Springer Science+Business Media. http://link.springer.com/article/10.1007/s11948-012-9419y/fulltext.html [9] National Institutes of Health, U.S. Department of Health and Human Services (2011). “2009 Guidelines on Human Stem Cell Research.” Stem Cell Information. (Online Article). http://stemcells.nih.gov/policy/pages/2009guidelines.aspx [10] World Medical Association General Assembly. (2013). “WMA Declaration of Helsinki – Ethical Principles for Medical Research Involving Human Subjects.” World Medical Association, Inc. (Online Article). http://www.wma.net/en/30publications/10policies/b3 [11] (2013). “Stem Cell Research.” Gallup.com. (Online Poll). http://www.gallup.com/poll/21676/stem-cellresearch.aspx [12] B. Bero, A. Kuhlman. (2010). “Teaching Ethics to Engineers: Ethical Decision Making Process Parallels the Engineering Design Process.” Springer Science+Business Media. (Online Report). http://link.springer.com/article/10.1007%2Fs11948-0109213-7/fulltext.html [13] K. Butler, J. Goverman, H. Ma, A. Fishman, et al. (2010). “Stem Cells and Burns: Review and Therapeutic Implications.” Journal of Burn Care & Research, Vol. 21, Issue 6, American Burn Center. (Online Article). pp. 874881. DOI: 10.1097/BCR.0b013e3181f9353a. [14] J. Shand. J. Berg, C. Boque. (2012). “Human Embryonic Stem Cell (hESC) and Human Embryo Research.” Pediatrics, Vol. 130, No. 5, American Academy of Pediatrics. (Online Article). pp. 972-977. http://pediatrics.aappublications.org/content/130/5/972 CONCLUSION: IMPROVEMENT OF THE BIOENGINEERING CODES Possible improvements of the current BMES Code of Ethics include the addition of ethical codes and tenets that apply to medical professionals, such as the Hippocratic Oath, the Nuremburg Code, and Declaration of Helsinki. By including these ethical codes directly in the BMES Code of Ethics, it will clear up discrepancies between the responsibilities of a bioengineer as an engineer and as a medical researcher. Additionally, from the struggles faced from trying to interpret the NSPE Codes of Ethics for my specific scenario, I believe that it needs to incorporate ethics about research done by an engineer in addition to the confidentially between employer and engineer. However, I do take into account that the NSPE Code of Ethics is for engineers in general and not directed towards any one specific engineering discipline, which may have made it difficult to involve any decisions about ethical research principles and guideline due to the expansive nature of engineering as a whole. Even if they are not improved, bioengineers, and engineers in general, should look to the codes as a starting point towards handling an ethicallycharged research design. REFERENCES [1] C. Brohem, L. Beatriz da Silva Cardeal, M. Tiago, M. Soengas, S. Berlanga de Moraes Barros, S. Stuchi MariaEgnler. (2011). “Artificial Skin in Perspective: Concepts and Applications.” National Institute of Health Public Access. (Online Journal Article). http://dx.doi.org/10.1111%2Fj.1755-148X.2010.00786.x [2] R. Shevchenko, S. James, S. E. James. (2010). “A review of tissue-engineered Skin Biocontructs Available for Skin Reconstruction.” Journal of the Royal Society Interface. (Online Journal Article). http://rsif.royalsocietypublishing.org/content/7/43/229 [3] G. Benichou, M. Fray, C. Lin, G. Tocco, Y. Yamada, S. Yun. (2011). “Immune Recognition and Rejection of Allogeneic Skin Grafts.” Future Medicine Ltd. (Online Report). http://dx.doi.org/10.2217/imt.11.2 [4] V. Wong, D. Wan, G. Gurtner, M. Longaker. (2012). “Regenerative Surgery: Tissue Engineering in General Surgical Practice.” World Journal of Surgery, Vol. 36, Issue 10, International Society of Surgery. (Online Article). pp. 2288-2299. DOI: 10.1007/s00268-012-1710-1 [5] (2007). “Code of Ethics for Engineers.” National Society of Professional Engineers. (Online Publication). Acknowledgements I would like to thank Jake Cline for proofreading my essay. I would also like to thank my writing instructor John Calvasina for answering questions about the assignment. 4 Gabrielle Schantz 5