"When Cameron was in Egypt's land ...". Annie Cavanagh/Dave McCarthy

President Obama lifted the Bush-era restrictions on embryonic stem cell lines last spring, but hundreds of cell lines have remained locked away undergoing review. Now the National Institutes of Health (NIH) has finally deemed 13 embryonic lines ready for use, and could make a decision on 20 or more by Friday, the Associated Press reports.

U.S. law still forbids the use of federal funding to create or destroy embryos, but the new stem cell lines all come from private fertility clinics. Such clinics typically make many leftover embryos that would normally end up being thrown away.

Scientists have found that they can replicate such embryonic stem cells indefinitely in their labs, and can also turn them into any of more than 200 tissue types in the human body — ideal platforms for repairing everything from heart tissue to spinal cords and brain cells. But controversy arose in past years due to moral concerns over destroying human embryos.

The NIH currently has 96 stem cell lines under review beyond the initial 13 approvals. Researchers say that they will submit another 250 for consideration, under new NIH regulations established this past summer.

U.S. researchers had chafed against the relatively few number of embryonic stem cell lines that they could use, even as scientists in other countries worked with no such restrictions. But they have still managed to accomplish small medical miracles in mice and other animals, such as creating embryonic stem cell patches to plug holes in the heart.

Scientists have also performed amazing feats with adult stem cells derived from body tissues, which don’t require destruction of embryos. A U.S. team at the University of Wisconsin in Madison transformed human skin cells into eye cells. Australian scientists even managed to restore sight to the blind by using stem-cell-coated contacts derived from the other eye of patients.

U.S. researchers at Stanford University also helped pioneer a method of deriving adult human stem cells from fat, as opposed to skin.

Such scientific advancement might someday even ensure that researchers could solely rely on adult stem cells, rather than embryonic stem cells. Chinese scientists announced this past summer that they had created live mice capable of reproduction from mouse skin cells, a small but crucial step.

But for now, sit back and wait for the day when you snort stem cells to get your medical fix.

To become an instant expert on the stem cell debate, see our recent Essential Guide to Stem Cells feature here.

[via Associated Press]