An intriguing new study reiterates the promise that stem cells hold for curing many diseases. Stem cells in the human body can be transformed into a variety of types of cells, depending on what biologic agents they're exposed to. Initially, stem cells were the subject of much more debate as they were harvested from fetuses, but now scientists are beginning to produce them in the lab by transforming patients' normal tissue cells into stem cells.
In the recent study, a team led by Dr. Mike Modo of the Institute of Psychiatry, King's College London investigated replacing stroke-damaged tissue in rats with new tissue from stem cells. Strokes, caused by blockages in brain blood vessels lead to dead areas of brain tissue. Past studies have looked at replacing this dead tissue with stem cells, which would grow into new brain tissue. However, they have met with little success.
The new study, though, shows such growth is possible; the cells just need a scaffolding to grow. In past studies, the cells migrated to other areas of the brain, making them essentially useless in fixing the problem. In the new study researchers attach them to a tiny scaffold made of a biodegradable polymer called PLGA, and coated this scaffolding in neural stem cells. The result is that the damaged brain tissue is regrown successfully in just 7 days. The technique has a strong likelihood of being able to be applied in humans.
States Dr. Modo, "We would expect to see a much better improvement in the outcome after a stroke if we can fully replace the lost brain tissue, and that is what we have been able to do with our technique. This works really well because the stem cell-loaded PLGA 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. Over a few days we can see cells migrating along the scaffold particles and forming a primitive brain tissue that interacts with the host brain. Gradually the particles biodegrade leaving more gaps and conduits for tissue, fibres and blood vessels to move into," Dr. Modo continued.
Magnetic Resonance Imaging (MRI) scans are used in the study to locate the damaged tissue and the optimal injection site for the scaffolding/stem cell mix. Subsequent MRI scans track the development of the brain tissue.
The researchers' next step will be to permeate the growing tissue with VEGF, a factor which promotes blood vessels to permeate a tissue. This will help bring blood flow to the developing brain mass, keeping it alive.
Professor Douglas Kell, chief executive of the Biotechnology and Biological Sciences Research Council (BBSRC) which funded the project, states, "Stroke is a leading cause of disability in industrialised countries. It is reassuring to know that the technology for treating stroke by repairing brain damage is getting ever closer to translation into the clinic. This crucial groundwork by Dr Modo and his colleagues will surely be a solid foundation of basic research for much better treatments in the future."
Joe Korner, Director of Communications at The Stroke Association (UK) adds, "This research is another step towards using stem cell therapy in treating and reversing the brain damage caused by stroke. It is exciting because researchers have shown they are able to overcome some of the many challenges in translating the potential of using stem cells into reality. The potential to reverse the disabling effects of stroke seems to have been proved. 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. Every five minutes someone in the UK has a stroke and it is vital that we do all we can to help those affected by stroke."
The new research is published in the journal Biomaterials.