Scientists create new type of stem cells in lab

A new type of human stem cell created by scientists, would be better at making replacement organs than existing stem cells, they claim.

Stem cells, theoretically speaking, have the ability to develop into any kind of cell, so they could be used to repair damaged organs or even build them from scratch. However, most stem cells were not that flexible, according to researchers.

The best ones were "pluripotent", meaning they could turn into anything and such cells had to be taken from embryos or made by reverting adult cells to their embryonic state, called induced pluripotent stem cells, 'New Scientist' reported.

However, these pluripotent stem cells still carried genetic baggage from their previous existence.

According to Austin Smith of the University of Cambridge, who led the team that developed the new cells, that baggage had been one of the confounding problems in this area.

The new cells had had their cellular memories wiped clean, with their genes cleansed of most methylation markers, so they behaved more predictably and transformed more consistently into other tissues.

According to the team, this would make them better building blocks for organs and tissues than existing embryonic stem cells.

According to Smith nothing had been written or drawn on them to tell them what to do or become. These cells could be a better and more pristine starting point, he added.

Meanwhile in a related development Japanese researchers had successfully implanted lab-grown retinal tissue from induced pluripotent stem cells (iPS) into a woman in her 70s - the world's first recipient of stem cells, Nature reported.

The woman who was suffering from an age-related macular degeneration, underwent a two-hour procedure under a team of three eye specialists led by Yasuo Kurimoto of the Kobe City Medical Center General Hospital. A 1.3 by 3.0 millimetre sheet of retinal pigment epithelium cells was transplanted into her eye.

The procedure was carried out at the Institute of Biomedical Research and Innovation Hospital, next to the RIKEN Center for Developmental Biology (CDB) where the cells had been developed and tested by ophthalmologist Masayo Takahashi.

The journal Nature reported that the procedure was performed after Takahashi received clearance for the human trials from a health ministry committee.

She took skin cells from the patient, converted them into iPS cells and then coaxed them into differentiating into retinal cells.