Nobody knows whether stem cells, the body’s so-called “master cells” that can differentiate into other cells, will ultimately be useful for repairing diseased or damaged tissue. Current knowledge about possible therapeutic uses remains so limited, according to speakers on a panel on potential applications of the technology, that commercial development remains a distant hope in most cases. And panelists warned that medical applications may never occur because of current restrictions on research involving human embryonic stem cells.

According to Marc D. Beer, chief executive officer of ViaCell, a Boston-based company that banks stem cell-rich blood from umbilical cords for study and possible therapeutic use, “Stem cells have the potential to cure.” But because of federal limits on the use of human embryonic stem cells, he said, “research is being curtailed. I’m watching basic research leave this country.”

Beer was one of the panelists taking part in the third annual Yale and New Haven Biotechnology Reception in October. He pointed to recent successes in experimental clinical trials in which insulin-producing islet stem cells from donor pancreases have completely cured type 1 diabetes in some patients. “Lack of cells,” said Beer, “is the biggest problem” for wider application of the transplant procedure.

Panel moderator Erin Lavik, Sc.D., assistant professor of biomedical engineering, studies the use of stem cells for repairing damaged spinal cords. She said government restrictions, coupled with a possessiveness on the part of those who developed a few approved stem cell lines, are hampering research despite the fact that “we do not know the potential of these cells.”

“When you don’t know,” said fellow panelist Earl M. Collier Jr., executive vice president of Genzyme Corp., “that’s not the time to legislate.”