Bone fragments were removed from the eyelid of a woman after a facelift that used her own stem cells yielded some unexpected results.
In addition to injecting stem cells to rejuvenate her skin, a second cosmetic product called dermal filler was added that is thought to have interacted with the stem cells to produce bone. Cosmetics do not need premarket approval in the US, therefore the US Food and Drug Administration (FDA) had not evaluated the procedure.
It took six and a half hours of surgery to remove the bone fragments from eyelid of the woman, who had been treated with her own stem cells three months earlier. Adult stem cells were isolated from abdominal fat collected from a liposuction procedure. The cells, called mesenchymal stem cells, can transform into several tissue types, including fat, cartilage and bone. They were injected into the patient's face, particularly around her eyes. As stem cells are thought to be able to repair aged or damaged tissue, this treatment was intended to rejuvenate the patient's skin.
However, rather than causing the skin to heal and appear younger, the mesenchymal stem cells turned into bone. Dr Allan Wu, the cosmetic surgeon who removed the bone fragments, told Scientific American that the dermal filler, used to reduce the appearance of wrinkles, may have caused this unexpected outcome. Dermal filler consists mainly of calcium hydroxylapatite, which is also used by scientists to encourage mesenchymal stem cells to turn into bone cells.
This facelift treatment did not require evaluation by the FDA at the time the woman received it. Cosmetic stem cell treatment occupies a grey area between cosmetics and drugs where it is not always clear whether a treatment needs premarket approval.
In July last year, a US federal court ruled that an orthopaedic stem cell product was to be classified as a drug (as reported in BioNews 667). The discussion centred on how much a person's cells can be manipulated before they constitute a drug. The court ruled that anything more than 'minimal manipulation' would render cells as a drug, making them subject to federal regulation.
The facelift treatment qualifies as both a cosmetic product and a drug, so it is unclear whether it requires federal regulation. Meanwhile, researchers worry that the uncontrolled use of stem cells by private clinics could impact negatively on the public's views of them.
'Many of us are super excited about stem cells, but at same time we have to be really careful', said Dr Paul Knoepfler, a cell biologist at the University of California, Davis, to Scientific American. 'These aren't your typical drugs. You can stop taking a pill and the chemicals go away. But if you get stem cells, most likely you will have some of those cells or their effects for the rest of your life. And we simply don't know everything they are going to do'.