Animal eggs for stem cell research: a path not worth taking

Ethical arguments concerning human-animal chimera research: a systematic review

Background

The burgeoning field of biomedical research involving the mixture of human and animal materials has attracted significant ethical controversy. Due to the many dimensions of potential ethical conflict involved in this type of research, and the wide variety of research projects under discussion, it is difficult to obtain an overview of the ethical debate. This paper attempts to remedy this by providing a systematic review of ethical reasons in academic publications on human-animal chimera research.

Methods

We conducted a systematic review of the ethical literature concerning human-animal chimeras based on the research question: “What ethical reasons have been given for or against conducting human-animal chimera research, and how have these reasons been treated in the ongoing debate?” Our search extends until the end of the year 2017, including MEDLINE, Embase, PhilPapers and EthxWeb databases, restricted to peer-reviewed journal publications in English. Papers containing ethical reasons were analyzed, and the reasons were coded according to whether they were endorsed, mentioned or rejected.

Results

Four hundred thirty-one articles were retrieved by our search, and 88 were ultimately included and analyzed. Within these articles, we found 464 passages containing reasons for and against conducting human-animal chimera research. We classified these reasons into five categories and, within these, identified 12 broad and 31 narrow reason types.

15% of the retrieved passages contained reasons in favor of conducting chimera research (Category P), while 85% of the passages contained reasons against it. The reasons against conducting chimera research fell into four further categories: reasons concerning the creation of a chimera (Category A), its treatment (Category B), reasons referring to metaphysical or social issues resulting from its existence (Category C) and to potential downstream effects of chimera research (Category D). A significant proportion of identified passages (46%) fell under Category C.

Conclusions

We hope that our results, in revealing the conceptual and argumentative structure of the debate and highlighting some its most notable tendencies and prominent positions, will facilitate continued discussion and provide a basis for the development of relevant policy and legislation.

Human-Animal Chimeras and Hybrids: An Ethical Paradox behind Moral Confusion?

The prospect of creating and using human-animal chimeras and hybrids (HACHs) that are significantly human-like in their composition, phenotype, cognition, or behavior meets with divergent moral judgments: on the one side, it is claimed that such beings might be candidates for human-analogous rights to protection and care; on the other side, it is supposed that their existence might disturb fundamental natural and social orders. This paper tries to show that both positions are paradoxically intertwined: they rely on two kinds of species arguments, "individual species arguments" and "group species arguments," which formulate opposing demands but are conceptually interdependent. As a consequence, the existence of HACHs may challenge exactly those normative standards on which the protection of HACHs may eventually be based. This ethical paradox could constitute the ultimate source of the "moral confusion" that some authors have suspected HACHs to provoke.

Ethical aspects of creating human-nonhuman chimeras capable of human gamete production and human pregnancy

In this paper I explore some of the moral issues that could emerge from the creation of human-nonhuman chimeras (HNH-chimeras) capable of human gamete production and human pregnancy. First I explore whether there is a cogent argument against the creation of HNH-chimeras that could produce human gametes. I conclude that so far there is none, and that in fact there is at least one good moral reason for producing such types of creatures. Afterwards I explore some of the moral problems that could emerge from the fact that a HNH-chimera could become pregnant with a human conceptus. I focus on two sets of problems: problems that would arise by virtue of the fact that a human is gestated by a nonhuman creature, and problems that would emerge from the fact that such pregnancies could affect the health of the HNH-chimera.

Stem cell policy exceptionalism: proceed with caution

The term "stem cell exceptionalism" has been used to characterize the policy response to controversies surrounding human embryonic stem cell research. For example, governments and funding agencies have adopted policies governing the derivation and use of human embryonic stem cell lines. These policies have effectively served to fill gaps in existing guidelines and regulations and signal that scientists are committed to a responsible framework for the conduct of research involving human embryos. Recent publications discuss whether ethical and policy issues associated with induced pluripotent cells (iPSCs) from non-embryonic sources create a need for further policy intervention. We suggest many of the issues identified by commentators may be addressed through the application of established policy frameworks governing the use of tissue, human stem cells, and research participation by human research subjects. To the extent, iPSC research intersects with hESC research (e.g. the creation of human gametes and/or embryos), the policy framework governing hESC appears sufficiently robust at this time.

Reframing the ethical issues in part-human animal research: the unbearable ontology of inexorable moral confusion

Research that involves the creation of animals with human-derived parts opens the door to potentially valuable scientific and therapeutic advances, yet invokes unsettling moral questions. Critics and champions alike stand to gain from clear identification and careful consideration of the strongest ethical objections to this research. A prevailing objection argues that crossing the human/nonhuman species boundary introduces inexorable moral confusion (IMC) that warrants a restriction to this research on precautionary grounds. Though this objection may capture the intuitions of many who find this research unsettling, it relies on mistaken views of both biology and moral standing, ultimately distorting the morally relevant facts. We critically examine IMC, identify mistaken essentialist assumptions, and reframe ethical concerns. The upshot is a stronger line of objection that encourages a more inclusive and productive ethical discourse.

Is the creation of admixed embryos "an offense against human dignity"?

The controversy over the creation of admixed human-nonhuman embryos, and specifically of what have been termed "cybrids," involves a range of ethical and political issues. It is not reducible to a single question. This paper focuses on one question raised by that controversy, whether creating admixed human-nonhuman entities is "an offense against human dignity. "In the last decade there has been sustained criticism of the use of the concept of human dignity within bioethics. The concept has been criticized as "vague" and "useless." Nevertheless, the concept continues to be invoked in bioethical discussion and in international instruments. This paper defends a concept of human dignity that is coherent but that is wider than contemporary post-Kantian approaches. "Human dignity" is best regarded as having a set of analogically related meanings, more than one of which is relevant to the field of bioethics. A more subtle understanding of the concept of human dignity can help identify what is ethically problematic in human-nonhuman combinations and so shed light on one aspect of the admixed embryo debate.

Ethics report on interspecies somatic cell nuclear transfer research

This report considers whether research involving the creation of human-animal interspecies somatic cell nuclear transfer (iSCNT) embryos raises new ethical issues, and if so, whether it requires additional or special criteria and oversight distinct from research on human-animal chimeras.

For love or money? The saga of Korean women who provided eggs for embryonic stem cell research

In 2004 and 2005, Woo-Suk Hwang achieved international stardom with publications in Science reporting on successful research involving the creation of stem cells from cloned human embryos. The wonder and success all began to unravel, however, when serious ethical concerns were raised about the source of the eggs for this research. When the egg scandal had completely unfolded, it turned out that many of the women who provided eggs for stem cell research had not provided valid consents and that nearly 75% of the women egg providers had received cash or in-kind payments. Among those who did not receive direct benefits, some cited patriotism as their reason for participating in embryonic stem cell research, hence the question "for love or money?"--namely, patriotism versus payment. This paper summarizes the Hwang debacle with particular attention to the egg scandal and ends with some preliminary thoughts on patriotism as a motive for research participation.

"You are our only hope": trading metaphorical "magic bullets" for stem cell "superheroes"

In the wake of two recent developments in stem cell research, it is a fitting time to reassess the claim that stem cells will radically transform the concept and function of medicine. The first is the U.S. Food and Drug Administration's decision in January 2009 to approve Geron Corporation's Phase I clinical trial using human embryonic stem cells for patients with spinal cord injuries. The second is the National Institutes of Health's decision to permit federal funding of research using donated IVF human embryos in their July 2009 Guidelines on Human Stem Cell Research. We are now poised to see whether stem cell research can deliver on what it promises. However, what exactly does it promise and how? Moreover, who is doing the promising? Turning to the use of metaphor can help us to answer these questions and enable us to develop a better appreciation of the unique features of promised stem cell therapies. Indeed, metaphors have exerted profound influence in medicine, and it is fitting that we seek new metaphors for new therapies where appropriate. In this case, other metaphors such as magic bullets or the Holy Grail cannot capture what is unique about stem cells. Accordingly, I propose a new metaphor: the stem cell superhero. Stem cell superheroes are characterized by the following traits: they are seemingly capable of fighting the evil of virtually all disease (unlike "magic bullets") and they seem to be our only hope of doing so, although to summon them we must make difficult moral choices. In the course of assessing the merits of three recent yet covert references to the superhero metaphor, I conclude that this powerful new paradigm employs a problematic logic (i.e., we cannot know that something is "our only hope"), but that the aspiration as such is a good one.