Wanting to know the secrets of her longevity, scientists have examined her blood and other tissues, and found some interesting things. For one, they found that about two-thirds of her white blood cells had been made by only two stem cells. (Stem cells create white blood cells, which are responsible for fighting off infection, and other functions.) Typically, about 1,000 stem cells actively make these blood cells. That finding implies that, predictably, stem cells die out throughout the years, and that there is indeed a limit to human life. But it also means that it may be possible to save stem cells from one's birth or youth, keep them alive outside the body, and re-inject them years later, to lengthen life.
Researchers at Brigham and Women's hospital have discovered that layered clay-that is, synthetic silicate nanoplatelets used in everything from glass and ceramics to food additives-can induce stem cells to become bone cells without needing any additional bone-inducing factors. In other words, the presence of this synthetic material can coax human stem cells into becoming bone all on its own, and that could have huge implications for the future of tissue engineering.
During 2012, two scientific teams announced, in separate studies, that they had transformed ordinary adult skin cells into neural cells, a breakthrough that could change the course of human stem cell research. Stem cells hold enormous potential for medicine because they can develop from undifferentiated cells into a variety of specialized ones. But their use has been stymied by ethical concerns; most are harvested from human embryos, which are destroyed in the process.
Despite the ethical and political differences they incite, stem cells are still a miraculous medicine, potentially able to change into whatever a sick body needs them to be. The only way to get them, though, is from actual embryos. If we could get around that, theoretically, the problems would be gone. Johns Hopkins scientists are making progress there, creating them from a non-controversial supply of something we have in bulk: adult red blood cells.
The first human eggs grown from human stem cells could be fertilised with human sperm cells later this year, potentially revolutionising fertility treatment for women. This could be one more step on the path toward reproduction sans human interaction - in this case, a potential parent wouldn't even need to donate her eggs. But it could also turn stem cells into an infinite loop, of egg cells into embryos into stem cells, and on and on, in a fractal-like repetition of reproduction.
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