Eye-opener as scientists grow lens cells

RESEARCHERS have established a way to grow human eye lens cells in the laboratory - the first time this has been done at 100 per cent purity.

The discovery means patients suffering congenital sight impairment caused by lens damage such as cataracts might one day be able to have a transplant, allowing them to grow an eye lens without the genetic defects their DNA would otherwise dictate.

The researchers from Monash University's Australian Regenerative Medicine Institute took stem cells and isolated the lens epithelium - the embryonic tissue from which the lens of the eye develops.

After isolating the cells from other cultures, Tiziano Barberi and Isabella Mengarelli then enabled the embryonic tissue to develop into lens cells in a culture dish.

This last step is often a challenge for scientists, as pluripotent stem cells have the ability to become any cell in the human body including skin, blood and brain matter. Once the stem cells have begun to differentiate, the trick is to control the process and produce only the desired cells - in this case lens cells. ''The cells that we grew and then isolated kept growing in a separate dish and they were able only to become lens cells,'' Professor Barberi said.

''This is the fundamental step that is required for anything you want to make starting from pluripotent stem cells.''

Whether their use is for testing new drugs or for transplantation into a patient, it is crucial to establish that the cells are pure. If they are not, then there is the potential for the cells to develop into cells other than eye lens cells.

''If you are able to purify them, then you can test anything and see what happens to that particular cell type. You can study toxicity or drug reaction in vitro,'' Professor Barberi said.

Published in Stem Cells Translational Medicine this month, the results could also speed up research because of the potential to allow scientists to conduct tests on human cells earlier - reducing the reliance on animal testing.

Human stem cells were first isolated in the late 1990s, making this field of scientific research relatively young.

''It's just started,'' Professor Barberi said. ''There will be many other advances in the future.''