Two patients who received retinal stem cell implants show potential signs of improved vision – despite having an incurable eye disease.
US firm Advanced Cell Technology told The Lancet that structural evidence confirmed the cells had attached to the eye’s membrane as hoped, and continued to survive throughout the next 16 weeks of the study, with no signs of rejection or abnormal cell growth.
The operation involved implanting embryonic stem cells into the damaged retina at the back of the eye. The controversial transplants of embryonic cells is part of an ambitious attempt to utilise stem cells. Stem cells have the ability to develop into any specialised tissue of the body. Such procedures face criticism from those who belief the use of human embryonic tissue to be unethical.
Dr Dusko Ilic, Senior Lecturer in Stem Cell Science at Kings College London, said that these early findings did not necessarily hint towards a viable treatment, saying: “we should keep in mind that people are not rats.
“The number one priority of initial clinical trial is always patient safety. If everyone expects that the blind patients will see after being treated with human embryonic stem cell-derived retinal pigment epithelium, even if the treatment ends up being safe (which is what Advanced Cell Technology are trying to determine in this trial), they risk being unnecessarily disappointed.”
It is too early to make conclusions yet, though it appears as if the procedure is safe.
UK stem cell expert Chris Mason said: “We do not have a complete answer yet. But it is a valuable next step.”
Scientists have developed an “invisibility cloak” that makes objects invisible to the naked eye.
The cloak, which is actually a lump of crystal, can only hide small objects such as paperclips and pins at the moment but it is the first of its kind to work in the perceivable spectrum of light. The groundbreaking research paves the way for more sophisticated devices in the future.
The cloaking device is made from two calcite prisms joined together to make a pyramid, with the underside of the pyramid coated in gold to make it reflective. The researchers found that calcite, a transparent crystal, has natural light-bending properties which help the device to hide objects. Light rays passing through the pyramid are bent, making the base of the pyramid look flat. “The cloaked region is the space at the bottom of the calcite prism,” Shuang Zhang, the lead researcher at the University of Birmingham said. “Anything you put there won’t be seen from outside.”
The device is not perfect, but it does pave the way for further breakthroughs. At present, the cloak itself is transparent though it is visible – it only hides small objects inside the prism. Under water, however, the cloak is almost completely invisible. Zhang said it may be possible to coat the cloak to make it less visible. It also must be placed on a surface to work.
Possible applications for use inevitably lie in military use, unfortunately. Future developments could be used to hide military hardware from view, although Zhang believes that it could be used for cosmetic purposes, too. “If you had a mole on your face, you could potentially cloak it so it won’t be seen,” Zhang said. “Though you do need a fairly large cloak to hide even a small thing.”
Still, it will be interesting to see what the future holds for cloaking devices. Perhaps Harry Potter’s invisibility cloak is not so far fetched after all…