Scientists grow artificial eye from stem cells

Biologists in Japan have succeeded in growing and implanting new eyeballs for the first time, prompting claims that scientists are close to a new cure for blindness.

Biologists in Japan have succeeded in growing and implanting new eyeballs for the first time, prompting claims that scientists are close to a new cure for blindness.

The latest breakthrough in biotechnology was reported by a team of scientists at Tokyo University, who grew an eyeball for a tadpole from cells harvested from frog embryos. Crucially, the cells were not rejected by the tadpole and successfully connected to its optic nerves.

The announcement is the third significant event in the field this week, after scientists at the British firm PPL Therapeutics announced on Wednesday a further advance in attempts to grow animal organs for human transplant.

The company said it had bred five cloned pigs, born on Christmas Day, without part of a gene closely involved in transplant rejection. Losing these genes is crucial to successful cross-species transplants, or xenotransplantation.

The Independent on Sunday has learnt that PPL is not, despite media reports, planning to sell off its discovery. The company is instead hoping to raise £20m to exploit its discovery by developing possible human treatments.

Ron James, PPL's managing director, said: "We are looking for partners rather than selling off this technology." The firm is approaching pharmaceutical companies or venture capitalists for backing.

PPL's decision to first announce its findings to the stock market led to accusations of unethical behaviour as a rival US team had bred similar cloned pigs in September, but refrained from publishing its findings until they were peer-reviewed by other scientists. PPL said since it was listed on the stock market, it was legally obliged to release commercially important information.

On Friday PPL's sister organisation, the Roslin Institute near Edinburgh, admitted that Dolly the sheep, the world's first cloned animal, had developed juvenile arthritis in her knees. That setback has deepened fears that cloned animals can develop and pass on genetic defects.

Leading scientists advising the European Commission have warned that animal transplants involving cells, tissues, or whole organs could carry potentially lethal animal viruses into humans or pose other unforeseen medical risks. The Commission is to carry out further research into reducing these risks.

The Japanese announcement follows the discovery by scientists in California in 2000 that human eye cells could be grown in laboratories and then successfully used to repair eye defects.