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

Abstract

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.

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

“…When considering the urgent unmet medical need for an additional source or repository of transplantable livers, it is our belief and that of others that the American public is ready to accept human-animal chimera research. 159 , 160 Recent polls in the United States have determined that the general public has an overall positive view towards xenotransplantation. 161 The complex ethical and moral profile surrounding the technology remains an omnipresent concern.…”

Xenotransplantation: Advancing Medical Innovation Through Cross-Species Transplantation

“…As we navigate the complex landscape of xenotransplantation, ethical, legal, and social considerations come to the forefront. Brown et al 7 engage in a critical examination of these aspects, particularly in the context of human-animal chimera research. They advocate for a proactive regulatory approach that is informed by scientific evidence and public engagement, emphasizing the importance of balancing innovation with responsibility.…”