The production of human-animal chimeras, i.e. animal organisms with human organs or tissues, is currently in the spotlight of ethical debates in the field of regenerative medicine. The process consists of introducing human stem cells into early animal embryos, so that the developing animal forms human organs and tissues inside its body.
Although this technique would enable organs to be obtained for transplantation and studies to be conducted on human disease, it nonetheless raises important ethical questions that must be resolved.
The main concern is that on combining human cells with animal embryos, human brain cells or germ line cells could arise in the animal offspring, cells that are strongly associated with human identity.
As a result of these ethical difficulties, on 23rd September 2015, the National Institutes of Health in the United States reported that, for now, it will not fund this type of research.
Nevertheless, this does not mean that there is a regulation prohibiting these techniques. In fact, a study conducted by researchers at the Salk Institute for Biological Studies in La Jolla, California (USA) was recently published in scientific journal Nature, whose findings could mean a major breakthrough in this field. However in addition to the aforementioned ethical obstacles, this experimental methodology still has a considerable number of technical obstacles.
The team, led by Juan Carlos Izpisúa Belmonte, has discovered a new type of embryonic stem cells called region-selective pluripotent stem cells (rsPSCs), which have molecular and functional characteristics that give them a unique ability to generate chimeric embryos among species.
The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.