The major medical and social problems in organ transplantation owing to the increasing shortage of donor organs is well known. Solutions must therefore be sought in the fairly near future that can resolve these issues. One of these is the production of animal chimeras in which quasi-human organs can be developed. This has been attempted using human embryonic stem cells injected into mice (Nature 521; 316-321, 2015), but the practice raises significant problems, from both a medical and ethical perspective. The main difficulty from a medical point of view is that, since this is an allogeneic material, it can give rise to as yet unresolved problems with immune rejection. The use of embryonic stem cell also entails what I would call insurmountable ethical difficulties, since obtaining these types of cells requires the destruction of human embryos. Furthermore, the transplanted human cells can colonise the organs of the recipient animal, so animals may be generated with practically human organs, which means great new ethical challenges.
Aside from the use of human embryonic stem cells, though, new possibilities have now been opened for these types of experiments with the development of adult somatic cell reprogramming from which so-called iPS cells can be derived. Since these can be obtained from somatic cells of the individual requiring the transplant, they minimise immune rejection. This is an attractive therapeutic possibility that looks likely to be implemented in the fairly near future.
An interesting article on this topic was published in the Journal of Medical Ethics last year (41; 970-974, 2015).
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.