Cloning and Stem Cell
Human embryonic stem cells are stem cells that are derived from the developing human embryo. They are most useful in research because of their ability to change into any type of cell, tissue or organ in the human body – that is, their pluripotency. As such they can be used in the treatment of a very large number of conditions. The main ethical issues arise from their source – donated embryos, most often left over from the IVF process.
Non-embryonic stem cells are stem cells that are not derived from an embryo. Two examples of these are cord-blood stem cells and induced pluripotent stem cells. Because they are not derived from embryos there is substantially less moral controversy about the use of these stems cells in research. However, there are limits to the use of non-embryonic stem cells. First, for all but induced pluripotent stem cells, other stem cells are not as versatile as the embryonic version and so they cannot give rise to the same range of human cells; and second, they do not help with research that is aimed at understanding the developmental mechanisms involved in these processes.
Admixed human embryos are a range of ‘combined’ human-animal embryonic cells. The most commonly used in research are ‘cybrids’. Cybrids are made by inserting the nucleus of a human cell into an animal egg from which the nucleus has been removed. They are useful in research because they are an easy way to create embryos so that the understanding and control of human embryos and development can be understood. Chimeras are usually formed by merging human and animal embryos whilst hybrids have human and animal chromosomes. The most common objection to these techniques involves claims about interfering with nature – by creating ‘half-human, half-animals’. A further objection points to the lack of dignity associated with the creation of these embryos. Such an objection relies on a particular conception of the moral status of the embryo.
Therapeutic cloning is cloning that is aimed at producing stem cells, tissue or organs for the therapeutic use of the individual from whom they are cloned. The advantage of therapeutic cloning is that the stem cells or other tissue created will have matched DNA to the recipient and so there will be little risk of tissue rejection. The main ethical issue associated with therapeutic cloning is that it requires the creation and destruction of an embryo, which on some views on the moral status of embryos is wrong.
The creation of part-human chimeric embryos and live-born chimeras could prove enormously beneficial as a tool for studying development and disease, testing therapeutic drugs, and generating tissues and organs for transplant.*
Chimeras are usually formed by merging human and animal embryos whilst hybrids have human and animal chromosomes. The most common objection to these techniques involves claims about interfering with nature – by creating ‘half-human, half-animals’. A further objection points to the lack of dignity associated with the creation of these embryos. Such an objection relies on a particular conception of the moral status of the embryo.**
On Thursday 15 April 2021, Professor Juan Carlos Izpisua Belmonte and his team announced in the journal Cell that they have injected human stem cells into monkey blastocytes, and succeeded in keeping some of the chimeric embryos alive for up to 20 days. It is hoped that by studying the 'crosstalk' between the monkey and human cells, it will soon be possible to generate human organs in different species that could help alleviate the worldwide shortage of organs for transplantation.
Full paper: Tao Tan, Jun Wu, Chenyang Si, et al, (2021), 'Chimeric contribution of human extended pluripotent stem cells to monkey embryos ex vivo', Cell, VOLUME 184, ISSUE 8, P2020-2032.E14, APRIL 15, 2021
*For an overview of the key ethical issues raised by part-human chimera research, and of possible regulatory approaches which may address these issues, see Julian Koplin and Julian Savulescu's article 'Time to rethink the law on part-human chimeras'.
**OUC's Katrien Devolder, Lauren Yip and Tom Douglas discuss the moral status of chimera, and the ethical issues surrounding such research in their freely available 2020 paper 'The Ethics of Creating and Using Human-Animal Chimeras', The ILAR Journal, Volume 60, Issue 3, Pages 434–438 [download author pre-print PDF]
Rethinking Moral Status, August 2021:
'Rethinking Moral Status' (Oxford University Press), edited by Steve Clarke, Hazem Zohny, and Julian Savulescu
- The first volume of its kind to consider how scientific and technological advancements impact our thinking about moral status
- Explores how both current and future developments — from human brain organoids and artificial intelligence, to cyborgs and post-humans — may challenge ideas about moral status
- Presents original ideas and discussion from leading philosophers and bioethicists
Common-sense morality implicitly assumes that reasonably clear distinctions can be drawn between the "full" moral status that is usually attributed to ordinary adult humans, the partial moral status attributed to non-human animals, and the absence of moral status, which is usually ascribed to machines and other artifacts. These implicit assumptions have long been challenged, and are now coming under further scrutiny as there are beings we have recently become able to create, as well as beings that we may soon be able to create, which blur the distinctions between human, non-human animal, and non-biological beings. These beings include non-human chimeras, cyborgs, human brain organoids, post-humans, and human minds that have been uploaded into computers and onto the internet and artificial intelligence. It is far from clear what moral status we should attribute to any of these beings.
There are a number of ways we could respond to the new challenges these technological developments raise: we might revise our ordinary assumptions about what is needed for a being to possess full moral status, or reject the assumption that there is a sharp distinction between full and partial moral status. This volume explores such responses, and provides a forum for philosophical reflection about ordinary presuppositions and intuitions about moral status.
Visit OUP website for further details. ISBN: 9780192894076
The Ethics of Embryonic Stem Cell Research
Devolder, K., (2015), 'The Ethics of Embryonic Stem Cell Research', (Oxford: Oxford University Press)
Embryonic stem cell research holds unique promise for developing therapies for currently incurable diseases and conditions, and for important biomedical research. However, the process through which embryonic stem cells are obtained involves the destruction of early human embryos. Katrien Devolder focuses on the tension between the popular view that an embryo should never be deliberately harmed or destroyed, and the view that embryonic stem cell research, because of its enormous promise, must go forward. She provides an in-depth ethical analysis of the major philosophical and political attempts to resolve this tension. One such attempt involves the development of a middle ground position, which accepts only types or aspects of embryonic stem cell research deemed compatible with the view that the embryo has a significant moral status. An example is the position that it can be permissible to derive stem cells from embryos left over from in vitro fertilisation but not from embryos created for research. Others have advocated a technical solution. Several techniques have been proposed for deriving embryonic stem cells, or their functional equivalents, without harming embryos. An example is the induced pluripotent stem cell technique. Through highlighting inconsistencies in the arguments for these positions, Devolder argues that the central tension in the embryonic stem cell debate remains unresolved. This conclusion has important implications for the stem cell debate, as well as for policies inspired by this debate.
"As an academic bioethicist with experience in the clinical setting, it is important to me that context and morality are married. Devolder's book accomplishes this task nicely, beginning in the introduction with a consideration of the potential use of embryonic stem cell (if not the embryo as a whole) for the alleviation of pain and disease. She convincingly directs us towards our moral obligation to allieviate suffering, underscoring that embryonic stem cell research is thus a moral enterprise." - Ayesha Ahmad, London School of Economics, Times Higher Education
"In her small but well written and insightful monograph Katrien Devolder is focusing on these "middle-ground positions" together with technical solutions to the dilemma. The author has been working on reproductive ethics in general and on embryo and stem cell research ethics in particular for more than ten years. Her book is based on several previously published articles, but it is far more than a mere collection or a re-use of essays." - Marco Stier, Ethical Theory and Moral Practice
"Devolders study is a tour de force, exhibiting real skill and imagination in the use of analogies to test our moral intuitions...The Ethics of Embryonic Stem Cell Research is a solid contribution to our stem cell debates. Neither partisan nor committed to advocacy for any side, it displays epistemic honesty and exhibits the value of philosophical analysis at its best." - Ronald M. Green, Monash Bioethics Review
