University scientists have paved the way for stem cells made from skin cells to be safely transplanted into humans.
The research has overcome one of the main health risks associated with use of such stem cells.
It could also ultimately spell an end to the need for human embryos as a source of stem cells.
The research was carried out by the University’s Medical Research Council (MRC) Centre for Regenerative Medicine and the University of Toronto.
It is the first time that scientists have been able to get human skin cells to act like embryonic stem cells without the need to use viruses.
The scientific findings are published in the journal Nature.
The research looked at transforming specialist cells to act like embryonic stem cells.
This then gives the cells - known as induced pluripotent stem cells - the ability to become any type of cell in the body.
The researchers discovered a technique where they were able to reprogramme the cells without using viruses.
The viruses modify the cells’ DNA in such a way that they could not be given to patients without greatly increasing the risk of cancer.
The researchers were also able to remove the four genes inserted for cell reprogramming, which should help avoid any abnormalities in how the cells develop.
This is a step towards the practical use of reprogrammed cells in medicine, perhaps even eliminating the need for human embryos as a source of stem cells.
Human cell reprogramming was first achieved in 2007.
However, the use of multiple viruses to deliver the four crucial genes - which can reverse the adult cell's fate - into the cells' DNA made them liable to switch on cancer-causing genes.
This previously made them unsafe for transplantation into patients. The research looked at both mouse and human skin cells.
Prior to the study attempts at non-viral reprogramming had only succeeded with mice cells, and were generally inefficient.
It will still take time before these induced pluripotent stem cells can be given to patients. Crucially, we need to have a method to generate the desired cell types from these stem cells. But I believe the team has made great progress.