They are not from human embryos, but the stem cells being packed into Perry Anderson's spine may help him heal from a surgery that failed to heal the first time, leaving him hobbled and unable to work for nearly three years.
The same type of cells, derived from bone marrow, one day may help heart attack patients recover, ease the misery of inflammatory bowel disease, and allow diabetics to continue producing insulin.
While the ethical debate rages over the use of stem cells taken from discarded human embryos, bone marrow stem cells, harvested both from cadavers and from live donors, are being developed for use against a range of illnesses.
These cells have shown a remarkable ability to form bone, cartilage, tendons, ligaments and fat, and are proving useful in experimental drug therapies to control diseases caused by the sometimes harmful effects of the body's own immune system.
In Sacramento, Dr. Pasquale Montesano is using them in spine surgery. At UC Davis, stem cell scientist Jan Nolta will try an adult stem cell-based drug in patients with Crohn's, a chronic and painful bowel disease.
More formally called mesenchymal stem cells, or MSCs, they come from the tissue tucked inside the bone cavity.
The U.S. Food and Drug Administration has approved only one MSC-derived product. Trinity, by Maryland-based Osiris Therapeutics Inc., was approved in 2005 for use in bone repair surgeries. It is marketed as an alternative to allograft, a separate surgical procedure in which the patient's own bone is taken from the hip and implanted elsewhere in the body.
Trinity (also sold under the name Osteocel) costs about $450 per cubic centimeter, an amount equivalent to a quarter teaspoon. A typical spinal surgery would require two to four cc's of the product.
Unlike a drug, Trinity is regulated as a human cell and tissue-based product. As such, its manufacturer cannot manipulate the cells by expanding them or adding drugs to them.
The MSCs used to make Trinity are taken from human cadavers the same way hearts, kidneys, livers and corneas are harvested after death and donated for transplantation.
On Thursday, they arrived in the operating room at Sutter Memorial Hospital in Sacramento in a tiny jar carefully packed in dry ice and stored in a foam cooler. Kept frozen, they can last up to five years. Once removed, they they must be used within 48 hours to be viable.
Montesano, the spine surgeon, says it's worth the trouble. He says Trinity works as well as other, costlier options and is especially useful in patients such as Anderson, whose prior spine fusion surgery failed.
The south Sacramento man was a painter when he fell from a 6-foot ladder and injured his back in 2004. A bad disk pinching a nerve in his neck caused him pain and searing headaches. Surgery to remove the disk and fuse the vertebrae in August 2006 never completely healed.
"The headaches aren't as bad, but my hands get numb, my arms are aching, I have lower back pain, anxiety attacks and depression," Anderson, 42, said before his surgery Thursday. "I have worked since I was 17. Now I can't do anything. I can't mow the yard, I can't go grocery shopping. It's ridiculous."
Montesano first removed the scar tissue and bony fragments from between the damaged vertebrae, careful to avoid Anderson's carotid artery and spinal cord.
Then, he took a graft made from cadaver bone and shaped like a square nut from a hardware store, widened the hole through the middle of it and packed it, like a sushi roll, with the crystal-like stem cells. After gently placing the graft into Anderson's spine, he tucked more cells around it.
When implanted in an area where new bone is needed to repair damage, Trinity preferentially forms new bone, said Bob Zambon, an Osiris scientist.
Montesano completed Anderson's operation by screwing a small metal plate into his spine to anchor the bone in place while it heals.
"Now we have to let Mother Nature take its course," he said.
Although an estimated 5,000 spine procedures with Trinity have been done so far in the United States, the data on how well it works in humans are not complete, and researchers still don't know whether it's superior to other technologies used to promote bone formation.
Nevertheless, the product already has generated $22 million in sales, and surgeons like Montesano say the high demand for it limits their ability to use it.
Dr. Kee Kim, a neurosurgeon at UC Davis, said even without the final human data, the university is evaluating Trinity, and he expects to be using it within months.
Mesenchymal stem cells taken from live donors also are being obtained by a handful of companies worldwide to develop drugs. Clinical trials using MSCs are under way in Iran for use against cirrhosis, in England against multiple sclerosis, and in Japan for severe gum disease.
The beauty of MSCs, said Zambon, the Osiris scientist, is that once harvested they can be expanded in culture and used in patients in the quantities their bodies need but can't naturally produce. In addition, patients in clinical trials treated with MSC-based drugs do not require other medication to prevent rejection.
One experimental MSC-based drug by Osiris is being fast-tracked through the FDA because of its promise against a deadly complication of bone marrow transplantation called graft vs. host disease.
In these cases, typically seen in childhood cancers, bone marrow transplanted to save a life actually rejects the patient's body often attacking the child's skin, eyes, stomach and intestines.
The Osiris drug, called Prochymal, works to suppress the patient's immune system and arrest the damage.
The drug also is being used in trials to address type 1 diabetes, a disease in which the body's beta cells are destroyed by the immune system.
At UC Davis, researchers next year will begin recruiting patients with Crohn's disease, an inflammatory bowel disorder. Participants, who have failed other treatments, will be given Prochymal.
"These cells are incredibly special because they temporarily stop the immune reaction against the bowel at the local level," said stem cell researcher Nolta. "And that allows them to heal."
Call The Bee's Dorsey Griffith, (916) 321-1089.
