Stem cell breakthrough – a jaw joint has been created in the lab using stem cells.

 Scientists have created part of the jaw joint in the lab using human adult stem cells. They say it is the first time a complex, anatomically-sized bone has been accurately created in this way. It is hoped the technique could be used to treat birth defects, arthritis or injury and plastic surgery. Lead researcher Dr Gordana Vunjak-Novakovic said: "The availability of personalised bone grafts engineered from the patient's own stem cells would revolutionise the way we currently treat these defects."

 However there exists a widespread controversy over human embryonic stem cell research that emanates from the techniques used in the creation and usage of stem cells. Human embryonic stem cell research is controversial because, with the present state of technology, starting a stem cell line requires the destruction of a human embryo and/or therapeutic cloning. However, recently, it has been shown in principle that adult stem cell lines can be manipulated to generate embryonic-like stem cell lines using a single-cell biopsy similar to that used in preimplantation genetic diagnosis that may allow stem cell creation without embryonic destruction. It is not the entire field of stem cell research, but the specific field of human embryonic stem cell research that is at the centre of an ethical debate.

Opponents of the research argue that embryonic stem cell technologies are a slippery slope to reproductive cloning and can fundamentally devalue human life. Those in the pro-life movement argue that a human embryo is a human life that is entitled to protection.

Contrarily, supporters of embryonic stem cell research argue that such research should be pursued because the resultant treatments could have significant medical potential. It is also noted that excess embryos created for in vitro fertilization could be donated with consent and used for the research.

The ensuing debate has prompted authorities around the world to seek regulatory frameworks and highlighted the fact that stem cell research represents a social and ethical challenge.