The American Public Is Ready to Accept Human-Animal Chimera Research

Gene editing in livestock: innovations and applications

Gene editing technologies have revolutionized the field of livestock breeding, offering unprecedented opportunities to enhance animal welfare, productivity, and sustainability. This paper provides a comprehensive review of recent innovations and applications of gene editing in livestock, exploring the diverse applications of gene editing in livestock breeding, as well as the regulatory and ethical considerations, and the current challenges and prospects of the technology in the industry. Overall, this review underscores the transformative potential of gene editing in livestock breeding and its pivotal role in shaping the future of agriculture and biomedicine.

Opinions on research involving human embryo models by researchers and the general public

Rules and ethical considerations regarding research on embryo models have been debated across numerous countries. In this paper, we provide insights from our attitude survey conducted among Japanese researchers, including members of the Japanese Society for Regenerative Medicine, and among the general public residing in Japan, the US, the UK, Canada, and Australia. Our survey revealed that many researchers expressed the need for clear guidelines for embryo model research. Furthermore, a minority but significant portion of the general public in each country expressed opposition to research on embryo models but did not oppose research involving real embryos.

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.

Cell Transplantation for Repair of the Spinal Cord and Prospects for Generating Region-Specific Exogenic Neuronal Cells

Spinal cord injury (SCI) is associated with currently irreversible consequences in several functional components of the central nervous system. Despite the severity of injury, there remains no approved treatment to restore function. However, with a growing number of preclinical studies and clinical trials, cell transplantation has gained significant potential as a treatment for SCI. Researchers have identified several cell types as potential candidates for transplantation. To optimize successful functional outcomes after transplantation, one key factor concerns generating neuronal cells with regional and subtype specificity, thus calling on the developmental transcriptome patterning of spinal cord cells. A potential source of spinal cord cells for transplantation is the generation of exogenic neuronal progenitor cells via the emerging technologies of gene editing and blastocyst complementation. This review highlights the use of cell transplantation to treat SCI in the context of relevant developmental gene expression patterns useful for producing regionally specific exogenic spinal cells via in vitro differentiation and blastocyst complementation.

The Ethics of Human Brain Organoid Transplantation in Animals

In this paper, we outline how one might conduct a comprehensive ethical evaluation of human brain organoid transplantation in animals. Thus far, ethical concerns regarding this type of research have been assumed to be similar to those associated with other transplants of human cells in animals, and have therefore not received significant attention. The focus has been only on the welfare, moral status, or mental capacities of the host animal. However, the transplantation of human brain organoids introduces several new ethical issues. Many of these are related to uncertainty regarding whether or not brain organoids might be conscious. While these concerns might not be immediately relevant, they warrant closer scrutiny. We discuss how various ethical issues are relevant to different stages of human brain organoid transplantation and can guide the ethical evaluation of research. Our examination would broaden the horizons of the debate on the transplantation of brain organoids.

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.

Interspecies Chimeric Barriers for Generating Exogenic Organs and Cells for Transplantation

A growing need for organs and novel cell-based therapies has provided a niche for approaches like interspecies chimeras. To generate organs from one donor species in another host species requires techniques such as blastocyst complementation and gene editing to successfully create an embryo that has cells from both the donor and the host. However, the task of developing highly efficacious and competent interspecies chimeras is met by many challenges. These interspecies chimeric barriers impede the formation of chimeras, often leading to lower levels of chimeric competency. The barriers that need to be addressed include the evolutionary distance between species, stage-matching, temporal and spatial synchronization of developmental timing, interspecies cell competition and the survival of pluripotent stem cells and embryos, compatibility of ligand–receptor signaling between species, and the ethical concerns of forming such models. By overcoming the interspecies chimera barriers and creating highly competent chimeras, the technology of organ and cellular generation can be honed and refined to develop fully functioning exogenic organs, tissues, and cells for transplantation.

How Artistic Representation Can Inform Current Debates About Chimeras

Researchers have increasingly been creating chimeras - combinations of cells from two species - raising profound ethical, social and scientific controversies. Such research could lead to the creation of animals such as pigs that contain human organs for transplantation, yet public fears have emerged. Scientists have thus called for enhanced public education and discussion, but these efforts require comprehension of the nature of public concerns. While arguments have viewed chimeras as either "good" or "bad," artists have long depicted chimeras in ways that can inform these discussions. Chimeras have a long history - the term itself is from Greek mythology - and have generated complex and ambivalent responses, reflecting deep questions regarding who we are as humans. Images across disparate cultures (such as Sphinxes and minotaurs) suggest how humans have long seen species boundaries as fluid but in differing ways. These images suggest that emotional, not just rational, utilitarian perspectives need to be addressed and that challenges may arise in altering views of all individuals. Nonetheless, public messages could draw on historic examples of positive such combinations. Thus, artistic representations can aid scientists, policymakers, educators and members of the public-at-large recognize and better comprehend and address the discomforts chimeras can foster.