CHENNAI: It took five years, more than seven challenges from scientists from across the globe and several rounds of arguments with an expert committee before a few city-based scientists managed to obtain the process patent for growing stem cells of the cornea on a synthetic gel to be used in transplants. Announcing this on Friday, scientists of Sankara Nethralaya and Nichi-In Biosciences (private) limited (NCRM) of Japan were visibly happy.
"This happens with most patent applications. But getting this one was special not only because we had to answer challenges from scientists in the US, UK, Japan and other European countries but also because it is our first international patent," said Dr HN Madhavan, professor of microbiology, Sankara Nethralaya, who filed the patent application on March 28, 2005. "We answered all the challenges patiently. The patent jury accepted it and granted us the patent on March 16, 2010," he said, displaying the patent and smiling at flashing media cameras. Beside him was Takayuki Kitagawa, the deputy consul general of Japan in Chennai, and Dr S S Badrinath, chairman emeritus of Sankara Nethralaya. "It's a red letter day for our hospital," said Dr Badrinath.
The team of scientists had successfully tested scaffold-less stem cell transplant in the eye on rabbits. "In 2003, a team of scientists identified a synthetic thermo-reversible gel, which liquefies when cooled. Mebiol gel, manufactured by a Japanese firm, was used as a scaffold to grow the rabbit's corneal stem cells. The stem cells of the cornea, located in an area called limbus, multiplied rapidly in the gel. Once the growth was satisfactory, we put the petridish in the refrigerator. The gel liquefied and limbal stem cells settled down. We then separated the stem cells from the liquid," Dr Badrinath said. "The stem cells were then loosely injected into the eyes of 12 rabbits blinded due to ocular surface damage. The little amount of gel that remained with the stem cells kept it glued to the site. We then bandaged this with a contact lens. In rabbits, besides restoring vision it reduced infection rates. We wanted to patent this process," he added.
But scientists from across the globe had raised objections on the type of genetic markers and other technical details such as molecular versions of the cells, time of harvest, collagens used. "On most occasions, we only had to convince the scientists and the jury that objections were not related to the patent we had applied for. This enormously delayed the process, yet we managed to persuade everyone," said Dr Samuel Abraham, director of NCRM who representet it at the hearing with the expert committee.
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