Stem cells could potentially repair damage caused by stroke
Scientists have developed a tiny scaffold of stem cells to fill holes in the brain caused by stroke damage.
So far tested in rats, the biodegradable balls loaded with stem cells were able to replace brain tissue in damaged areas within a week.
The team, who report the results in Biomaterials, are now planning to add in a protein to encourage new blood vessel growth in the treated areas.
But there is still a long way to go in stem cell therapy for stroke survivors.
Previous research in injecting stem cells into rats with stroke damage has had some success but, because they lack structural support, the cells end up migrating into surrounding healthy tissue, the researchers said.
To try to overcome this problem, the researchers developed tiny polymer balls, a tenth of a millimetre across, and loaded them with neural stem cells.
They then injected thousands of these into the void left behind when a stroke kills of healthy brain tissue.
The ready-made support structure helped the stem cells to form new brain tissue in the cavity, the team said.
Study leader Dr Mike Modo, from the Institute of Psychiatry at King's College London, said: "This works really well because the stem cell-loaded particles can be injected through a very fine needle and then adopt the precise shape of the cavity.
"In this process the cells fill the cavity and can make connections with other cells, which helps to establish the tissue."
He said over a few days they were able to see cells migrating along the scaffold particles and forming a primitive brain tissue that interacts with the host brain.
In time, the particles biodegrade leaving more gaps and conduits for tissue, fibres and blood vessels to move into.
With researchers at Nottingham, they now plan to use a protein called VEGF that encourages new blood vessel growth in order to link up the new tissue with the rest of the brain.
They also need to compare the scaffold technique with results from just injecting stem cells alone.
Professor Douglas Kell, chief executive of the Biotechnology and Biological Sciences Research Council who funded the research, said: "It is reassuring to know that the technology for treating stroke by repairing brain damage is getting ever closer to translation into the clinic."
Joe Korner, director of communications at The Stroke Association, said the research had showed the ability to overcome some of the barriers in translating stem cells into a realistic treatment.
"However the development of stem cell therapy for stroke survivors is still in the early stages and much more research will be needed before it can be tested in humans or used in practice."