Posted by Stephanie on December 12, 1999 at 00:02:48:
Dec. 11, 1999
Reuters Health Information
NEW YORK -- Scientists have developed a way to grow an artificial version of the cornea -- the clear, front part of the eye.
Since the artificial cornea responds to chemicals and other irritants in much the same way as human eye tissue, it might reduce the need for testing the safety of drugs, cosmetics and other products in the eyes of live animals, one of the researchers told Reuters Health in an interview.
The effort to develop an artificial cornea grew out of research on how the eye heals after it is injured, according to Rejean Munger, of the University of Ottawa in Canada. Ideally, the researchers would like to study donated human corneas, but "all the good ones are being used for transplants," Munger told Reuters Health.
Under the leadership of Dr. May Griffith, the research team began the project by taking cells from the three layers of the human cornea. These cells were then infected with a harmless virus containing a gene that triggered the cells to continuously produce new cells.
The investigators then used these "immortalized" cells to grow into an artificial version of the cornea. After about 2 weeks, they compared the structure and function of the artificial corneas to natural corneas.
The newly formed corneas resembled human corneas in several ways, the authors report in the December 10th issue of the journal Science. When exposed to a mild eye irritant, the artificial corneas responded in much the same way as human corneas. Also, the cells were as transparent as natural corneas.
These artificial corneas are "functionally similar" to human corneas, Munger told Reuters Health. Hopefully, it will be possible to start using artificial corneas instead of live animals in product safety tests, he said.
Eventually, artificial corneas might be transplanted into people, according to Munger, but before that can happen, researchers will have to refine the tissue. For example, even though artificial corneas are transparent and respond to irritants as human eyes do, they do not have the proper shape needed to allow people to see, he noted.
"There's still a lot of work to be done," Munger said.
SOURCE: Science 1999;286:2169-2172.
c. Reuters News Service