Custom-made human embryos for medical research

LONDON Human embryos created specifically for medical research have been used for the first time to provide stem cells in a study conducted in US. Susan Lanzendorf and colleagues from the Jones Institute for Reproductive Medicine, Norfolk, Virginia, report in July Fertility and Sterility that the future production of human embryonic stem cell lines for therapeutic use is possible with the use of donated gametes.Research on embryonic stem cells currently utilizes tissue from embryos created during fertility treatment that are not used and otherwise discarded. But Lanzendorf et al. aspirated oocytes from 12 donor women and inseminated them with frozen-thawed donor sperm from two men using standard IVF methods. They generated 110 embryos, of which 40 developed to the blastocyst stage following culture in sequential media (Fertil Steril 2001, 76:132-137).Using immunosurgery techniques the inner cell masses were isolated from the blastocysts and were cultured for 4–11 days on primary mouse embryonic fibroblasts (PMEFs). Viable cell colonies were moved every 7–10 days onto fresh PMEFs in the presence of leukaemia inhibitory factor and evaluated for appropriate cell surface markers. At the end of the process there were three healthy embryonic stem cell lines were developed for use in subsequent basic research studies.The team obtained ethical approval for this study from four independent ethical review committees including members of the clergy, ethicists and lawyers. The authors writes that their goal was to "ensure that both oocyte and sperm donors understood the nature and purpose of the research before their participating in the study". They carefully screened the donors and gave them physical tests to guarantee that they were healthy. In addition, a psychologist interviewed the volunteers to ensure they understood the study and had no emotional problems before being asked to consent.However opponents of stem cell research were quick to voice their disapproval. "This is really ghoulish — creating human embryos for the specific purpose of destroying them," legislative director for the National Right to Life, Douglas Johnson, said in an interview with Reuters Health. "It's totally wrong to kill human embryos for research", Johnson added.Religious US broadcaster Pat Robertson said in a BBC news interview, "Before long, we'll be harvesting body parts from fully formed people. Once you begin this concept of utilitarian use of cells, then everything is up for grabs". Other religious leaders were equally critical. Richard Doerflinger, a leading US catholic anti-stem research campaigner, quoted by the BBC, called the work by Lanzendorf et al. a "grotesque practice".Those involved in the Jones project say it is more ethical, not less, to create new embryos for research because everyone involved understands exactly what is happening throughout the project — not necessarily the case when discarded embryos are used. There are also practical advantages in being able to choose the germ cell donors, for example, younger women produce higher quality eggs. Currently most of the eggs come from women who are in their mid-30s, relatively late in their childbearing years, when the risk of genetic alterations is high.Embryonic stem cells can develop into all of the body's tissues and thus could theoretically be used to repair the damage cause by a host of degenerative diseases such as Alzheimer, emphysema, kidney and heart failure. The capacity of human embryonic stem cell to build complex organs in culture is entirely unexplored. Extracellular matrices or existing organs (human or otherwise) can act as scaffolding and may eventually enable the production of complex organs such as the kidney or lung.Most scientists around the world are holding fire on their embryonic stem cell projects, awaiting a decision from politicians. President Bush is under increasing pressure from both sides of the stem-cell debate to decide soon whether federal funds can be used for research involving embryonic stem cells. A 1995 US law prohibits the use of federal money for research in which a human embryo would be destroyed or placed at risk. However, the Jones Institute for Reproductive Medicine, where the first successful IVF was done in the US, is a privately funded institution and such research was perfectly legal.In Europe, the German ethics council will make a decision on funding stem-cell research this July (2001), while British scientists have the legislative go-ahead to carry out research on cloned human embryos. In January 2001 the House of Lords approved 212 votes to 92 the British Government proposal to amend the Human Fertilization and Embryology Act. UK scientists can now apply for licences on stem-cell research and the laboratory work here is expected to start by the end of the year.

Custom-made human embryos for medical research

Scientists in the US have created stem cells from human embryos derived from germ cells donated explicitly for providing tissue for medical research.

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