|Year : 2019 | Volume
| Issue : 1 | Page : 3-8
A general evaluation of stem cell studies and human cloning from the ethical, faith, and legal perspective
Cemal Alper Kemaloglu1, Fatih Birtek2
1 Department of Plastic, Reconstructive and Aesthetic Surgery, Erciyes University, Kayseri, Turkey
2 Department of Criminal and Criminal Procedure Law, Erciyes University, Kayseri, Turkey
|Date of Web Publication||4-Jan-2019|
Dr. Cemal Alper Kemaloglu
Department of Plastic, Reconstructive and Aesthetic Surgery, Erciyes University, Kayseri
Source of Support: None, Conflict of Interest: None
Stem cell and cloning studies bear promising potential in the field of regenerative medicine with their exciting and innovative features. The wide range of applications of these cellular treatments and their permanent repairing qualities foretell that a completely different scientific paradigm is emerging for the future. However, satisfactory insight has not yet been developed with respect to the moral status and legal aspects of these studies. Furthermore, their potentially untoward side effects are not understood well enough to compare with the benefits they provide for human life. In general, attempts are made to place the subject in a pattern composed of the sanctity of life, the unique characteristics of being an individual, the boundaries drawn by beliefs, and the basic principles of law. This article will discuss the benefits of stem cell and cloning studies as well as their undeveloped medical, ethical, religious, and legal aspects.
Keywords: Ethics, faith, human cloning, legal, plastic surgery, stem cell
|How to cite this article:|
Kemaloglu CA, Birtek F. A general evaluation of stem cell studies and human cloning from the ethical, faith, and legal perspective. Turk J Plast Surg 2019;27:3-8
|How to cite this URL:|
Kemaloglu CA, Birtek F. A general evaluation of stem cell studies and human cloning from the ethical, faith, and legal perspective. Turk J Plast Surg [serial online] 2019 [cited 2019 Jul 16];27:3-8. Available from: http://www.turkjplastsurg.org/text.asp?2019/27/1/3/249400
| Introduction|| |
The era we live in has witnessed astonishing discoveries by humankind along with the medical advances that are encouraging humanity's hope for healthier and happier lives on Earth. Within the past 20 years, in particular, studies on cell biology and stem cells have given humanity the good news that a new paradigm is emerging in the treatment of diseases. With this new strategy, many chronic diseases can be completely eliminated, and a physiological and permanent result can be achieved to replace the missing parts of an organ through tissue reconstruction. However, several ethical and legal issues in the recognition and implementation of the cellular treatments still wait to be clarified, similar to the challenges that precede the realization of all revolutionary transformations in science.
Stem cell studies have taken the lead in cellular treatments. A new transformation started in this area with the derivation of embryonic stem cells in 1998 and the achievements made by Takahashi et al. in 2006 in eliciting pluripotent stem cells by inducing human fibroblasts. Consequently and after just 6 years, the practice of stem cell treatment has begun in patients with macular degeneration.,, In the years following these developments, interest in stem cells has risen steadily with an increasing number of studies in the fields of regenerative medicine and tissue and organ engineering. Nowadays, stem cells are recognized as potential tools in the treatment of several chronic diseases and in organ reproduction as they can be converted into many different types of cells. This fact continues to excite doctors, scientists, and patients alike. However, due to the different types of stem cells and their various differentiation potentials, medical deontologists and jurists have not yet reached a consensus on the ways and methods to be used when making use of these cells, causing gaps in the practice.
Cloning is another issue parallel to stem cell studies, catching humanity unprepared in the current era. Cloning is a Greek word and refers to a group of branches having the same characteristics. The term cloning has subsequently been imported by biology, meaning “the reproduction of another organism which is a genetically identical copy of the original.” With the birth of the sheep Dolly, the first living organism cloned in 1997, the intention to use this method for reproduction and individual organ/tissue production was considered. However, at the same time, these considerations raised questions as to what the ethical and legal limits of this procedure should be.,
After the potential of stem cells for regenerative and tissue engineering was discovered, plastic surgeons began showing interest in these new treatment modalities, particularly for reconstructive purposes. In this context, adult stem cells began being used for skin rejuvenation, cosmetic breast augmentation, overcoming wound healing difficulties, recovery from local tissue ischemia, scar remodeling, and skin engineering. However, clinical experience has shown that stem cell therapies may not be completely safe and that they may carry some risks for patients including “tumor formation, immunological reactions, unexpected cell behavior, and unknown long-term health effects.” Following these reports, some governments started to impose strict regulations in the field of stem cell modalities, but the discussions are not over yet.
Between 2001 and 2009, a total of 20,072 articles were published in the literature concerning stem cell research, of which 212 were affiliated with plastic surgeons. This shows that stem cell therapies are very popular among plastic surgeons and that this will likely be the case in the future also. However, the ethical and moral issues associated with these topics have not been completely resolved in either the Turkish or the international legal systems yet. This present article will elaborate on the existing concepts, conditions, and solutions individually from the ethical and legal aspects, and from the aspect of faith.
Stem cell and cloning concepts
Stem cells allow the development of tissues and organs during the embryonic and fetal stages. These cells are essential for the protection, regeneration, and repair of tissues and organs after birth and in adulthood. In short, stem cells are the cells that can regenerate, differentiate into other cells, and that can also be cloned. These abilities that stem cells possess suggest their use in the treatment of diseases that develop due to the absence or dysfunction of cells. For example, patients with paralysis, diabetes, Parkinson's disease, and heart failure are considered to be those patient groups that may benefit from treatment for this purpose. Moreover, any organ that can be produced using stem cells can also be used in the treatment of patients with organ failure. Therefore, due to all these advantages, there has been an increase in stem cell research, studying which methods provide the highest quality and most reliability in achieving them.
In regenerative medicine, the stem cell concept is divided into two groups according to their biologic origins. These groups are known as an adult and embryonic stem cells. Today, adult stem cells are the most commonly derived from bone marrow and fat tissue. These cells remain unchanged among differentiated cell groups and can be transformed into the cells in the surrounding tissues. In this respect, it is assumed that adult stem cells have multipotent features with the capacity to differentiate into a single germ line. Today, various connective tissue elements such as bone, cartilage, fat, and muscle tissues can be derived from adult stem cells in laboratory conditions. In addition, adult stem cells can be reprogrammed to behave-like embryonic stem cells, called induced pluripotent stem cells (iPSC), that can fully differentiate into all cell types. This technique can be a potential alternative to embryonic stem cells since it is less expensive and carries fewer risks for researchers and donors. However, it has raised its own ethical dilemmas, which will be discussed later.
Embryonic stem cells are derived from the inner cell layer of the blastocyst at the preimplantation stage. The stem cells at this stage are pluripotent and can be transformed into all cell types developing from the endoderm, mesoderm, and ectoderm. Today, hematopoietic cell precursors, adipocytes, muscle cells, chondrocytes, and other tissue cells can be derived from embryonic stem cells with genetic modifications and by modifying their culture media. In this regard, embryonic stem cells have a much broader field of use.
With their potential for a high differentiation capacity and their ability to transform into all kinds of cells belonging to any organ, embryonic stem cells are potent and effective alternatives to current treatment options. However, because the cultivation of embryonic stem cells is fatal for the embryo, this powerful alternative has become a debatable issue from the ethical, religious, and legal standpoints. Therefore, many countries have legislated several laws nationally limiting the use of embryonic stem cells. This issue will be discussed later in the article.
On the other hand, cloning represents a further aspect of the stem cell studies. The cloning of an organism is an artificial way of reproduction where the nuclear acid of the somatic cell is transferred into an oocyte. In this case, the child that will be born will be genetically identical to the copied individual. Humanity's reproduction of the syngeneic state of identical twins in the last century has been recognized as an outstanding achievement for modern science.
Cloning suddenly became popular in 1996 with the birth of Dolly, which was the first artificially cloned live sheep. Consequently, a successful advertising campaign for cloning was carried out and the method was proposed as a potential process for several purposes, such as reproducing a child for parents who wish to have a child identical to their deceased one; reproducing a child for individuals who wish to have a child after the untimely death of the spouse, or for infertile couples to have children; or reproducing individuals with high-quality characteristics. However, all rabbits, mice, and pigs reproduced by artificial cloning over the years, including Dolly, have suffered from health problems both during the natal period and after the birth, losing their lives sooner. For this reason, confidence in cloning has declined, and the international academy of science has declared that human cloning is absolutely not safe. Nevertheless, public interest in cloning studies has not diminished, and it has become a subject of ethical, religious, and legal debate, built atop scientific grounds. On one side of this debate are those who argue that cloning may save lives, and on the other side are those who claim that cloning is intervention in nature, rendering it an issue of human rights and dignity.
The ethical and legal dimensions of stem cell studies
The debates on stem cell studies focus, particularly on embryologic stem cell studies. As the embryo loses its capacity to survive during the process of cultivating embryonic stem cells, the question about the ethical and legal rights of this embryo has become an important issue. Due to the versatility of the issue and the disagreements as to the survival of the embryo, the Turkish and international legal systems all contain ambiguities and variations with respect to embryonic stem cell studies.
From the legal perspective, expressions on the starting time of life are included in the Turkish Civil Code. The article 28 declares that “the personality commences when the child is completely born, and it will come to an end with its death. “The article then continues stating that “a child gains the capacity to have rights at the time of conception provided that she or he is born alive.” The code, then, means that the commencement of life and the legal status of the embryo start with conception.
However, debates about the initiation of life and about embryonic stem cell studies are not so simple as to be solved by these provisions of law. It is argued that these legal provisions may be valid for the embryos of the natural fertilization process, but they will not cover the artificial fertilization that will take place outside the mother's womb. Furthermore, some in the embryonic stem cell studies argue that the embryo is nonhuman existence without owning any right to life, and as such, it cannot benefit from the protection of life in the Constitution. According to this hypothesis, the embryo is regarded as “not mature enough” to be covered by the protection of human dignity concept.
The clearest statements about practicing the embryonic stem cell procedures in Turkey are published in the “embryonic stem cell studies” circular published by the Ministry of Health in 2005. This circular states that the use of stem cells is debatable from the legal and ethical points of view, declaring that the ministry continues to work on this issue with its legal, cultural, and ethical aspects within the concept of harmonization with the European Union legislative to finalize the legal arrangements. The circular ends with the declaration that embryonic stem cell studies have been banned until the conclusion of the associated work. After the publication of the circular, no embryonic stem cell study has been published due to the aforementioned prohibition. However, Turkish law recognizes the current embryonic stem cell studies within the “experiments and clinical trials on humans” provisions of Article 90 of Turkish Penal Code, and agrees that any embryonic stem cell treatments conducted with the purpose of treatment cannot be subject to any penalties provided that the study is conducted in compliance with the provisions of Turkish Penal Code.
Another ethical argument still underway involves adult stem cells (adiposite-derivated stem cells and iPSC). In particular, fat grafting and adipose-derived stem cells are very often used for esthetics, and these therapies have raised ethical concerns relating to standards for its safety and efficacy. Current scientific data on the safety and efficacy of stem cell-based esthetic procedures are limited and recommended that surgeons should use it carefully due to its potential side effects such as tumor formation and unwanted immune responses. iPSC, which is another type of adult stem cells, is derived from human somatic cells, but their epigenetic profiling is different from that of somatic cells. iPSCs are reprogrammed to have the capacity of pluripotent cells, but many mechanisms of the reprogramming are still unknown. Hence, this raises ethical concerns about the process of somatic cell reprogramming. For example, during the reprogramming process, some tumor suppressor genes may be deleted, and this may affect the iPSCs' abilities to differentiate, proliferate and develop, and may cause tumorigenicity. Thus, the ethical and moral aspect of these treatments is still being discussed, and it is generally accepted that the requirements for proof of principle and safety should be higher, particularly if the cells have been manipulated extensively in vitro or have been derived from pluripotent stem cells.
The ethical and legal aspects of cloning
Two advisory rulings by the Parliamentary Assembly of the Council of Europe, of which Turkey is a member, prompted the prohibition of embryo creation and cloning for research purposes regardless of whether the embryo is alive or dead. In this regard, the most comprehensive and detailed regulation that can be referred to is the “Convention for the Protection of Human Rights and Dignity of the Human Being with Regard to the Application of Biology and Medicine” developed by the Council of Europe with respect to cloning in 1997 with an additional protocol called the “Protocol for the Prohibition of the Copying of Human Beings” signed in 1998. This convention and the protocol are two important legal documents that are binding at the international level. The text clearly declares that human cloning is contrary to ethics and human integrity and dignity. According to the convention; “any generation of human embryos for research purposes is prohibited” (Article 18/2).
Despite this declaration, no joint legal arrangements on this issue have been brought into effect either in the European Union member countries or in other countries. As of today, there are 35 countries that have legislated several laws to regulate the human cloning. Some countries have allowed human embryo cloning for research purposes only, and some others have prohibited this cloning for any purpose. In the world, it is noteworthy that cloning for therapeutic purposes is generally not prohibited. However, cloning for reproductive purposes is prohibited and subject to criminal sanctions. In Turkey, it is accepted that both embryonic stem cell and cloning studies are prohibited by the “embryonic stem cell studies” circular, published by the Ministry of Health in 2005.
Stem cell studies and cloning from the aspect of faith
Both the Islamic faith and the Jewish and Christian doctrines consider that it is not right to give birth to a genetically exact copy of a human being. However, the legal representatives of different religions declared different opinions on research using cloned embryos for the protection of life.
According to Conservative Jews, an embryo is not human before the 40th day and therefore does not deserve protection. Moreover, legal rights are gained only after being born and, the right to live should be protected to the full extent only after the birth. Going by this Jewish point of view, cloned embryos have life-saving potential, so there is no harm in conducting medical research on them. Furthermore, the embryonic stem cell studies should continue, provided that any life-threatening risk is prevented.
On the other hand, Christian Catholics believe that the embryo is sacred and no medical interventions should be performed to cause an end to its life for any purpose. For this reason, Catholics have supported stem cell studies for organ reproduction while strongly objecting to the cloning of an embryo for research purposes.
According to the religion of Islam, the embryo is a sacred existence starting from the moment of fertilization, progressing to become a human being. Therefore, its integrity should be protected. However, a dichotomy exists among Islamic thinkers whether to allow any research on this existence or not. Those, who advocate that research cannot be done, have postulated that any research that would cause embryonic destruction is contrary to the right to life and therefore to the religion, too, arguing against embryonic stem cell research. However, another group did not see any problems in conducting adult stem cell studies. According to this postulate, the mother's uterus, i.e., a natural biological environment, is required for the embryo to become a human being. On the other hand, an embryo outside the mother's womb will not be human because it is deprived of a natural biological environment; therefore, medical and biological studies can be conducted on it. Apart from all this, all Islamic thinkers object to human cloning.
| Discussion|| |
The right to life is a fundamental human right guaranteed by the Constitution. According to this, every human being should receive the most current treatment needed for his or her life. At this point, current technological advances are reflected in the field of medicine, and genetically based models have begun to be discussed in the treatment of diseases. At the forefront of these models are stem cell studies along with the replacement of missing tissues or the replenishment of damaged organs using cloned embryos. However, aiming to eradicate many diseases, these methods have generated a large amount of excitement as well as introducing intense discussions. The basic questions, on which no consensus has been reached, concern the legal, religious, and moral status of an embryo.
As discussed previously, the legal position of a fertilized oocyte has already been clarified. However, it does not hold true for an oocyte artificially fertilized under laboratory conditions. The major underlying reason for this uncertainty is the conflict between the protection of the right to life of a living organism versus the protection of the right to life of an embryo, which has not been born yet. Accordingly, the ability to form a new living organism, the use of embryos as a cell/organ reservoir, and their potential to clarify the unknowns of the regenerative medicine and cell biology all pose a big problem as these potential developments are opposed by the fact that they are all fatal to embryos. Moreover, the lack of any consensus on the answers to the questions as to whether and when an embryo can be accepted as a human being makes this issue more complex and difficult to resolve. For all these reasons, many countries attempted to create solutions by legislating diverse laws nationally.
For example; The Canadian Parliament passed a law in 2004, allowing research on stem cells derived from embryos in compliance with certain provisions. However, it prohibited human cloning. Again, the French Parliament adopted a new bioethics law in 2004, allowing embryonic stem cell research, but described human cloning as a “crime against the human species.” The British Parliament similarly prohibited human cloning and allowed experimental stem cell research only for the treatment of diabetes, Parkinson's and Alzheimer's disease. In addition, the UK legislation took the embryo under protection starting from the 14th day after the fertilization, describing the period preceding this 14th day as the “pre-embryo” period.
In Turkey, according to the “Regulation of Assisted Reproductive Treatment Centers Act” it is strictly forbidden to take embryos created for transferring purposes and use them for research purposes. According to Annex 17/3 of the Regulation (the Sanction Form), it is forbidden to keep, use, transfer, or sell the embryo for any purpose other than reproduction. According to this provision, it is illegal to conduct research on any embryo regardless of the method used to obtain it.
The only issue on which a consensus has been achieved, coming out of the shadows of the complexities of the law, is the option of producing tissues or organs to replace damaged ones or replenishing tissues in regenerative medicine using adult stem cells (bone marrow or fat). For example, today, leukemia can be treated with bone marrow transplantations, which is itself a stem cell transfer, or with adipose-derived stem cell transplantations for skin rejuvenation. Although these therapies are generally accepted as safe and effective, recent research shows that they may have adverse effects such as growing tumor formation, immunological reactions, unexpected cell behavior, and unknown long-term health effects. For this reason, adult stem cell therapies have started to raise their own ethical dilemmas, and the use of these modalities is restricted by some Governments or Local Ethics Committees. For example, the American Society of Plastic Surgeons recommended that surgeons conduct these procedures within the Institutional Review Board–approved clinical studies and in compliance with US Food and Drug Administration regulatory guidelines.
Another type of adult stem cells is iPSC, which is dermal fibroblast reprogrammed to behave like embryonic stem cells. These stem cell therapies are generally used to treat damaged organs by reproducing tissue from the patient's own dermal fibroblast and then transferring it back to the patient again. Thus, the risk of the patient's immune system rejecting the transplanted organ is eliminated along with the need to search for donors. For example, an adult bladder was produced using the iPSC for the first time in 2006, and this bladder was successfully transplanted to the individual. This was followed by the transplantation of a three-dimensional trachea (trachea) created using stem cells in 2008. At present, research on the reproduction of the heart, liver, kidney, and other tissues continue by using today's tissue engineering techniques. Considering the existing and potential benefits of the aforementioned studies, the destruction of embryos at the end of embryonic stem cell studies will terminate the further potential benefits that will be obtained from the outcomes of those studies. Furthermore, as we stated before, iPSCs are not accepted as a totally safe procedure, and further studies are needed to learn how to maintain genetic stability in the process of somatic cell reprogramming, and how to avoid tumorigenicity in iPSCs.
Another application envisaged for adult stem cell treatment concerns regenerative medicine. Stem cell therapy aims to growth and regenerates neurons to allowing paraplegic and quadriplegic patients to be treated. However, one must note that stem cell therapy today is still in its infancy. Therefore, any announcement of that kind of treatment for patients as a definite solution in the treatment of their diseases may lead to serious ethical problems due to the potential for disappointment in the future. For this reason, instead of prohibiting stem cell studies, these studies must be permitted within the scope of regulations, and the limits of these studies in this field should be defined by legal regulations that include consistent, clear, and specific provisions. In addition to these, plastic surgeons must strongly advise to receive “informed consent” forms for all stem cell applications include esthetic and reconstructive procedures.
Human cloning is one of the most important inventions of the last century. Cloning is conducted basically for two different purposes. The first of these is cloning for reproductive purposes and the second is cloning for therapeutic purposes. Reproductive cloning can be in the form of creating an exactly identical twin of the individual or allowing an infertile individual to have a child. However, the creation of an identical copy of an individual has been recognized as an intervention that is completely contrary to nature and not right. It is widely thought that the present genetic diversities will be eradicated and the balance of nature will be destroyed if these predictions are correct. For this reason, almost all countries have issued legislation banning human-made human cloning.
The ethical aspects of cloning for therapeutic purposes are discussed, too, since these cloned embryos for therapeutic purposes will eventually perish, sacrificing their lives. As a result, this fact is accompanied by several legal and ethical debates, creating some legal issues. As the subject has not been clarified from a legal or ethical standpoint yet, the scientific policies are stuck between the potential benefits one side, and the moral values and the legal regulations that continue to prohibit on the other.
None of the Celestial religions indulge the cloning of an exact copy of a human being. On the other hand, each individual religion declared different opinions on the therapeutic cloning and on conducting research on those cloned embryos. There is no doubt that all these disagreements are underpinned by the question as to when the embryo achieves human status. As this issue is associated with the concept of spirit, falling in the scope of metaphysics, no definite consensus has been achieved yet.
| Conclusion|| |
Rapid technological advances in studies on cell therapies offer permanent solutions in the future for many chronic diseases that cannot be treated currently. However, it is noteworthy that there are no established rules on the legal status of embryonic stem cells or on cloning either in our national legal system or in international documents. Today's modern legal system must fill in the gap on this issue swiftly and finalize the debate resulting from current biotechnological advances, at least in its own terms because, even now, hundreds of people have genetic diseases that cannot be cured, many infertile couples cannot have children, and most importantly, many individuals lose their lives due to organ failure in violation of their basic right, which is the right to life.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Takahashi K, Tanabe K, Ohnuki M, Narita M, Ichisaka T, Tomoda K, et al.
Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell 2007;131:861-72.
Tibbetts MD, Samuel MA, Chang TS, Ho AC. Stem cell therapy for retinal disease. Curr Opin Ophthalmol 2012;23:226-34.
Thomson JA, Itskovitz-Eldor J, Shapiro SS, Waknitz MA, Swiergiel JJ, Marshall VS, et al.
Embryonic stem cell lines derived from human blastocysts. Science 1998;282:1145-7.
Daar AS, Sheremeta L. The science of stem cells: Ethical, legal and social issues. Exp Clin Transplant 2003;1:139-46.
Ayala FJ. Cloning humans? Biological, ethical, and social considerations. Proc Natl Acad Sci U S A 2015;112:8879-86.
Habets MG, van Delden JJ, Bredenoord AL. The inherent ethical challenge of first-in-human pluripotent stem cell trials. Regen Med 2014;9:1-3.
Hyun I, Lindvall O, Ahrlund-Richter L, Cattaneo E, Cavazzana-Calvo M, Cossu G, et al.
New ISSCR guidelines underscore major principles for responsible translational stem cell research. Cell Stem Cell 2008;3:607-9.
Eryilmaz T, Oktem F, Durgun M, Ozakpinar R, Tellioglu AT. Stem cell studies in plastic surgery: Are plastic surgery journals really interested in stem cells? Plast Reconstr Surg 2012;129:604e-6e.
Yerdelen E. Cloning (Copying) in Turkish criminal code. AUHFD 2014;63:643-85.
Çakar AN. Stem cell definition, types, and ethical aspects. Turk Clin J Plast Surg Spec Top 2015;4:1-6.
Hedrick MH, Daniels EJ. The use of adult stem cells in regenerative medicine. Clin Plast Surg 2003;30:499-505.
Martin GR. Isolation of a pluripotent cell line from early mouse embryos cultured in medium conditioned by teratocarcinoma stem cells. Proc Natl Acad Sci U S A 1981;78:7634-8.
Petrini C. Bioethics of clinical applications of stem cells. Int J Mol Sci 2017;18. pii: E814.
McCulloch EA, Till JE. Perspectives on the properties of stem cells. Nat Med 2005;11:1026-8.
Reproductive Cloning of Human Beings: Status of the Debate in the United Nations General Assembly: Report by the Secretariat, WHO Report; 2005.
Report on the Ethical and Legal Aspects of Stem Cell Research, Council of Bioethics Society of Turkey on Stem Cell Research and Applications, Bioethics Society of Turkey; 2009.
Hakeri H. Intentional Killing Crimes. Ankara: Seçkin Publishing; 2006.
Zengin MA. Protection of Human Rights against Biological Practices and Medical Interventions. Ankara: Adalet Publishing; 2012.
The Ministry of Health Circular on the Embryonic Stem Cell Research, General Directorate of Health Services. Ankara: Ministry of Health, Republic of Turkey; 2005.
Hakeri H. Medical Law. Ankara: Seçkin Publishing; 2018.
Herberts CA, Kwa MS, Hermsen HP. Risk factors in the development of stem cell therapy. J Transl Med 2011;9:29.
Zheng YL. Some ethical concerns about human induced pluripotent stem cells. Sci Eng Ethics 2016;22:1277-84.
Pattinson SD, Caulfield T. Variations and voids: The regulation of human cloning around the world. BMC Med Ethics 2004;5:E9.
Campbell CS. In whose image? Religion and the controversy of human cloning. Second Opin 1999;1:24-43.
Cohen CB. Renewing the Stuff of Life. New York: Oxford University Press; 2007.
Steinberg A, Loike JD. Human cloning: Scientific, ethical and Jewish perspectives. Assia Jew Med Ethics 1998;3:11-9.
Friend W. Catholic perspectives on stem-cell research and use. Origins 2003;32:682-6.
Shannon TA. Human cloning: Examining religious and ethical issues. Valparaiso Univ Law Rev 1998;32:773-92.
Ilkilic I, Ertin H. Ethical aspects of human embryonic stem cell research in the Islamic world: Positions and reflections. Stem Cell Rev 2010;6:151-61.
Larijani B, Zahedi F. Islamic perspective on human cloning and stem cell research. Transplant Proc 2004;36:3188-9.
Fadel HE. Developments in stem cell research and therapeutic cloning: Islamic ethical positions, a review. Bioethics 2012;26:128-35.
Seyalıoğlu İ, Eraslan B, Hot İ, Demircan T, Çetin G. Genetic, ethical, and legal approaches to cloning. Turk J Forensic Med 2007;21:31-45.
White AC, Lowry WE. Refining the role for adult stem cells as cancer cells of origin. Trends Cell Biol 2015;25:11-20.
Nayar HS, Caplan AL, Eaves FF, Rubin JP. The ethics of stem cell-based aesthetic surgery: Attitudes and perceptions of the plastic surgery community. Aesthet Surg J 2014;34:926-31.
Atala A, Bauer SB, Soker S, Yoo JJ, Retik AB. Tissue-engineered autologous bladders for patients needing cystoplasty. Lancet 2006;367:1241-6.
Macchiarini P, Jungebluth P, Go T, Asnaghi MA, Rees LE, Cogan TA, et al.
Clinical transplantation of a tissue-engineered airway. Lancet 2008;372:2023-30.
Walters L. Human embryonic stem cell research: An intercultural perspective. Kennedy Inst Ethics J 2004;14:3-8.