Rats with brain injury showed great functional recovery after the stem cell treatment. In the study conducted by a team from Hokkaido University Graduate School of Medicine in Sapporo, Japan, autologous bone marrow stem cells were injected into the carotid artery of the injured rats which helped the cells move right to the damaged sites and start repairing. The study results which were given light in the February issue of the journal Neurosurgery hold promise for treating brain injuries in humans.
The "intra-arterial" technique of injecting stem cells tested in the study is new. Using it, the researchers aimed to deliver stem cells right to the brain without letting them enter general circulation. To trace whether stem cells migrated straight to the brain the researchers labeled them with “quantum dots” before injecting. Produced with nanotechnology, “quantum dots” behave as fluorescent semiconductors emitting near-infrared light able to penetrate bones and skin, thus enabling monitoring of stem cell behavior in the body during the four weeks after the transplantation.
Seven days prior to the stem cell injection, the researchers induced brain injury in the rats. Then they collected bone marrow stem cells, cultivated them, labeled with “quantum dots” and injected back to the rats. With their non-invasive optical imaging, the researchers were able to observe that the injected stem cells moved directly to the brain. They migrated through the capillaries to the damaged parts and started their reparative work within three days.
Four weeks after the transplantation, the rats that received the stem cell treatment showed a significant recovery of the lost motor functions while the rodents from the control group showed no improvements. Having examined the brains of the treated animals, the researchers discovered that stem cells had given rise to different brain cell types thus helping to heal the injured sites.
The finding can pave way for treating traumatic brain injury, as well as stroke, in humans. Stem cells injected into the carotid artery can move directly to the brain to start recovery as early as possible, and this procedure is quite simple. What is more important is the level of functional recovery of the brain after the stem cell treatment.