Scientists from the UK's University of Cambridge had successfully rebooted stem cells known as the pluripotent type of stem cells. The rebooted cells are comparable to the embryonic cells that are seven to 10 days old before they are implanted in the mother's womb.

Pluripotent type of stem cells are just one of the three stages of stem cells. Other stages are the totipotent stem cells which are the most versatile and the multipotent which are the least versatile. Stem cells are unspecialized cells which have the capacity to develop and become cells that have highly specialized functions. Their classification is based on their plasticity or developmental versatility.

Pluripotent type of stem cells are deemed to have the capacity to form almost any bodily cell types. These would include the heart, blood, nerve and muscle. They can be created in a laboratory by using cells that have been extracted from an embryo at a pristine stage or from adult cells which have been stimulated to reach a pluripotent stage.

In the past, generating human pluripotent cells which are authentically in a blank state have been difficult. Researchers have so far gathered cells which have moved a little further towards the developmental state and have shown characteristics of being identified into certain types of cell.

Experts believe that regenerating tissue in stem cell science could deliver new ways of treating ailments which currently have no cures. These would include eye diseases, heart ailments, stroke and Parkinson's.

Researchers also learned that compared with mouse cells, generating lab-produced human stem cells is more difficult to control.

"Capturing embryonic stem cells is like stopping the developmental clock at the precise moment before they begin to turn into distinct cells and tissues," said MRC Prof Austin Smith, co-author of the research. "Scientists have perfected a reliable way of doing this with mouse cells, but human cells have proved more difficult to arrest and show subtle differences between the individual cells."

Researchers introduced two genes known as NANOG and KLF2 to compensate for the human cells' unresponsive behavior to LIF. The latter is a type of protein that is used by the researchers to freeze mouse cells in a form of early pluripotency. NANOG and KLF2 work better for human cells and have enabled a network of genes which manipulate the cell to reboot and reach its early pluripotent state.

"Having a source of pristine stem cells which can be precisely changed into clinical-relevant cell types is a major step forward," said Chris Mason, a stem cell expert and professor of regenerative medicine at University College London.