Human-Animal Chimeras: The Moral Insignificance of Uniquely Human Capacities

Producing Human Livers From Human Stem Cells Via Blastocyst Complementation

The need for organ transplants exceeds donor organ availability. In the quest to solve this shortage, the most remarkable area of advancement is organ production through the use of chimeric embryos, commonly known as blastocyst complementation. This technique involves the combination of different species to generate chimeras, where the extent of donor cell contribution to the desired tissue or organ can be regulated. However, ethical concerns arise with the use of brain tissue in such chimeras. Furthermore, the ratio of contributed cells to host animal cells in the chimeric system is low in the production of chimeras associated with cell apoptosis. This review discusses the latest innovations in blastocyst complementation and highlights the progress made in creating organs for transplant.

Chimeric Livers: Interspecies Blastocyst Complementation and Xenotransplantation for End-Stage Liver Disease

Orthotopic liver transplantation (OLT) currently serves as the sole definitive treatment for thousands of patients suffering from end-stage liver disease; and the existing supply of donor livers for OLT is drastically outpaced by the increasing demand. To alleviate this significant gap in treatment, several experimental approaches have been devised with the aim of either offering interim support to patients waiting on the transplant list or bioengineering complete livers for OLT by infusing them with fresh hepatic cells. Recently, interspecies blastocyst complementation has emerged as a promising method for generating complete organs in utero over a short timeframe. When coupled with gene editing technology, it has brought about a potentially revolutionary transformation in regenerative medicine. Blastocyst complementation harbors notable potential for generating complete human livers in large animals, which could be used for xenotransplantation in humans, addressing the scarcity of livers for OLT. Nevertheless, substantial experimental and ethical challenges still need to be overcome to produce human livers in larger domestic animals like pigs. This review compiles the current understanding of interspecies blastocyst complementation and outlines future possibilities for liver xenotransplantation in humans.

What Do Chimeras Think About?

Non-human animal chimeras, containing human neurological cells, have been created in the laboratory. Despite a great deal of debate, the status of such beings has not been resolved. Under normal definitions, such a being could either be unconventionally human or abnormally animal. Practical investigations in animal sentience, artificial intelligence, and now chimera research, suggest that such beings may be assumed to have no legal rights, so philosophy could provide a different answer. In this vein, therefore, we can ask: What would a chimera, if it could think, think about? Thinking is used to capture the phenomena of a novel, chimeric being perceiving its terrible predicament as no more than a laboratory experiment. The creation of a thinking chimera therefore forces us to reconsider our assumptions about what makes human beings (potentially) unique (and other sentient animals different), because, as such, a chimera's existence bridges our social and legal expectations about definitions of human and animal. Society has often evolved new social norms based on different kinds of (ir)rational contrivances; the imperative of non-contradiction, which is defended here, therefore requires a specific philosophical response to the rights of a thinking chimeric being.

A Technological and Regulatory Review on Human-Animal Chimera Research: The Current Landscape of Biology, Law, and Public Opinion

Organ transplantation is a highly utilized treatment for many medical conditions, yet the number of patients waiting for organs far exceeds the number available. The challenges and limitations currently associated with organ transplantation and technological advances in gene editing techniques have led scientists to pursue alternate solutions to the donor organ shortage. Growing human organs in animals and harvesting those organs for transplantation into humans is one such solution. These chimeric animals usually have certain genes necessary for a specific organ's development inhibited at an early developmental stage, followed by the addition of cultured pluripotent human cells to fill that developmental niche. The result is a chimeric animal that contains human organs which are available for transplant into a patient, circumventing some of the limitations currently involved in donor organ transplantation. In this review, we will discuss both the current scientific and legal landscape of human-animal chimera (HAC) research. We present an overview of the technological advances that allow for the creation of HACs, the patents that currently exist on these methods, as well as current public attitude and understanding that can influence HAC research policy. We complement our scientific and public attitude discussion with a regulatory overview of chimera research at both the national and state level, while also contrasting current U.S. legislation with regulations in other countries. Overall, we provide a comprehensive analysis of the legal and scientific barriers to conducting research on HACs for the generation of transplantable human organs, as well as provide recommendations for the future.

Moral Status and the Oversight of Research Involving Chimeric Animals

The use of nonhuman animals in research has long been a source of bioethical and scientific debate. We consider the oversight and use of nonhuman animals in chimeric research. We conducted interviews with twelve members of embryonic stem cell research oversight committees, nine members of institutional animal care and use committees, and fourteen scientists involved in human-nonhuman-animal chimeric research in different areas of the United States. Interviews addressed animal welfare and conceptual issues associated with moral status and humanization of nonhuman animals that contain human cells. Our findings suggest that concepts of enhanced moral status and consciousness are not very useful in human-nonhuman-animal chimeric research in part because their meanings are not easily defined, which presents challenges to applying the concepts in research. Instead, scientists and oversight committee members we interviewed seemed to rely on standard assessments of changes in animal welfare when focusing on the ethics of human-animal chimeric research.

Knowledge graphs of ethical concerns of cerebral organoids

OBJECTIVES

The rapid development of cerebral organoid technology and the gradual maturity of cerebral organoids highlight the necessity of foresighted research on relevant ethical concerns. We employed knowledge graphs and conducted statistical analysis with CiteSpace for a comprehensive analysis of the status quo of the research on the ethical concerns of cerebral organoids from a bibliometric perspective.

MATERIALS AND METHODS

We performed a statistical analysis of published papers on cerebral organoid ethics, keyword co-occurrence graph, literature co-citation and knowledge clustering graph to examine the status of the ethics research, internal relationship between technological development and ethical research, and ethical concerns of the academia. Finally, we used a keyword time zone graph and related statistics to analyze and predict the trends and popular topics of future cerebral organoids ethics research.

RESULTS

We demonstrated that although the ethical concerns of cerebral organoids have long been discussed, it was not until 2017 that the ethical issues began to receive more attention, when cerebral organoids were gradually mimicking the human brain more closely and increasingly being combined with chimera research. The recent key ethical concerns are primarily divided into three categories: concerns that are common in life sciences, specific to cerebral organoids, and present in cross-fields. These increasing ethical concerns are inherently related to the continual development of technology. The analysis pointed out that future research should focus on the ethical concerns of consciousness that are unique to cerebral organoids, ethical concerns of cross-fields, and construction and improvement of legislative and regulatory systems.

CONCLUSIONS

Although research on cerebral organoids can benefit the biomedicine field, the relevant ethical concerns are significant and have received increasing attention, which are inherently related to the continual development of technology. Future studies in ethics regarding cerebral organoid research should focus on the ethical concerns of consciousness, and cross-fields, as well as the improvement of regulatory systems.

Applications of CRISPR-Cas9 as an Advanced Genome Editing System in Life Sciences

Targeted nucleases are powerful genomic tools to precisely change the target genome of living cells, controlling functional genes with high exactness. The clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR-Cas9) genome editing system has been identified as one of the most useful biological tools in genetic engineering that is taken from adaptive immune strategies for bacteria. In recent years, this system has made significant progress and it has been widely used in genome editing to create gene knock-ins, knock-outs, and point mutations. This paper summarizes the application of this system in various biological sciences, including medicine, plant science, and animal breeding.

Human-Animal Chimeras, "Human" Cognitive Capacities, and Moral Status

In "Human-Animal Chimeras: The Moral Insignificance of Uniquely Human Capacities," Julian Koplin explores a promising way of thinking about moral status. Without attempting to develop a model in any detail, Koplin picks up Joshua Shepherd's interesting proposal that we think about moral status in terms of the value of different kinds of conscious experience. For example, a being with the most basic sort of consciousness and sentience would have interests that matter morally, while a being whose consciousness featured the riches of loving affection, say, might have greater moral status and therefore deserve some sort of priority if the interests of the two beings conflicted. This approach represents an improvement over the more common, transparently anthropocentric habits of thinking about moral status, whether in connection with evaluating human-animal chimera research, deciding what one can ethically eat, or pursuing some other moral inquiry.

Bioethical issues in genome editing by CRISPR-Cas9 technology

Genome editing technologies have led to fundamental changes in genetic science. Among them, CRISPR-Cas9 technology particularly stands out due to its advantages such as easy handling, high accuracy, and low cost. It has made a quick introduction in fields related to humans, animals, and the environment, while raising difficult questions, applications, concerns, and bioethical issues to be discussed. Most concerns stem from the use of CRISPR-Cas9 to genetically alter human germline cells and embryos (called germline genome editing). Germline genome editing leads to serial bioethical issues, such as the occurrence of undesirable changes in the genome, from whom and how informed consent is obtained, and the breeding of the human species (eugenics). However, the bioethical issues that CRISPR-Cas9 technology could cause in the environment, agriculture and livestock should also not be forgotten. In order for CRISPR-Cas9 to be used safely in all areas and to solve potential issues, worldwide legislation should be prepared, taking into account the opinions of both life and social scientists, policy makers, and all other stakeholders of the sectors, and CRISPR-Cas9 applications should be implemented according to such legislations. However, these controls should not restrict scientific freedom. Here, various applications of CRISPR-Cas9 technology, especially in medicine and agriculture, are described and ethical issues related to genome editing using CRISPR-Cas9 technology are discussed. The social and bioethical concerns in relation to human beings, other organisms, and the environment are addressed.

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.

Animals with Human Cells in Their Brains: Implications for Research

In "Human-Animal Chimeras: The Moral Insignificance of Uniquely Human Capacities," Julian Koplin argues against the views that all uniquely human traits have moral significance or that all the traits humans have in common with other animals "are morally insignificant." He recommends instead the adoption of "a better framework for thinking about the moral status of part-human beings," one that emphasizes the "phenomenal value (or disvalue)" chimeric animals are likely "to enjoy (or suffer)." If the moral status of these chimeric animals is grounded in the phenomenal value of their interests-that is, their interests as nonhuman animals-current protections for animals used in research may be inadequate to protect those interests.

The Moral Status of Human-Animal Chimeras with Human Brain Cells

While there is not unanimity (across time or cultures), almost all who read this commentary will think that both they and a toddler have a moral status higher than that of a rat. For instance, they will think that a third party who has to choose whom to save from death should choose them over the rat, and the toddler over the rat. But what is it about humans that gives us this greater moral status? This question is particularly pressing when considering that scientists have begun creating human-animal chimeras with brains composed partly or wholly of human cells. In "Human-Animal Chimeras: The Moral Insignificance of Uniquely Human Capacities," Julian Koplin focuses on the moral implications of such experiments and those that use (or plan to use) these chimeras to study diseases and treatments. How should we understand the concerns about moral status that have been raised about such chimeras? In this commentary, I interpret these concerns differently from Koplin and respond to his suggestion that the greater one's ability to draw value from certain kinds of conscious experiences, the greater one's moral status.