The use of human embryos for research on embryonic stem (ES) cells is currently high on the ethical and political agenda in many countries. Human embryonic stem cells (hES cells) are currently discussed not only by the biologists by whom they were discovered but also by the medical profession, media, ethicists, governments and politicians. There are several reasons for this. On the one hand, these ‘super cells’ have a major clinical potential in tissue repair, with their proponents believing that they represent the future relief or cure of a wide range of common disabilities; replacement of defective cells in a patient by transplantation of hES cell-derived equivalents would restore normal function. On the other hand, the use of hES cells is highly polemical because they are derived from human pre-implantation embryos.

“Stem cells” are primitive cells with the capacity to divide and give rise to more identical stem cells or to specialize and form specific cells of somatic tissues. Broadly speaking, two types of stem cell can be distinguished: embryonic stem (ES) cells which can only be derived from pre-implantation embryos and have a proven ability to form cells of all tissues of the adult organism (termed “pluripotent”), and “adult” stem cells, which are found in a variety of tissues in the fetus and after birth and are, under normal conditions, more specialized (“multipotent”) with an important function in tissue replacement and repair.

Disponível em: <https://academic.oup.com>. Acesso em: set. 2017. Adaptado.