Experiments conducted over brain-injured rats that stem cells injected through carotid artery travel to the brain directly thereby increasing its functional recovery to a great extent. Dr Toshiya Osanai, a leading researcher of Hokkaido University Graduate School of Medicine in Sapporo, Japan said that carotid artery injection accompanied with any type of in-vivo optical imaging to check track stem cells post transplantation is advancement for stem cell transplantation in human brain trauma injuries. They also reviewed a new intra-arterial technique of stem cell transplantation in rats, aimed at injecting stems cells to the brain directly and not via general circulation. Before injecting stem cells into carotid artery they injected TBI in the rats.
Before injecting stems cells into the rats, these stem cells were obtained from rat’s bone marrow and then they were labeled with quantum dots which are biocompatible, fluorescent semiconductor. Quantum dots are made with nanotechnology and emit near-infrared light having much longer wavelength capable of penetrating skin and bone. This allows successful non-invasive method of monitoring stem cells for four weeks following transplantation. Using this in vivo optical imaging technique scientists observed that the stem cells which they injected entered the brain on the first attempt itself without entering general circulation. Scientists also observed that it took not more than three hours for the stem cells to move from capillaries to the injured part of the brain.
In the fourth week of their research, the scientists observed that the rats involved in this study attained a considerable recovery of motor function as compared to the animals excluding this stem cell transplant group that showed no signs of recovery. The team of scientists arrived at the conclusion that stem cells transformed into different brain cell types and helped in healing injured brain area.
Past years have seen a tremendous growth in stem cell therapy to cure and treat diseased and certain conditions. For those suffering from brain injuries, TBI and stroke, stem cells have proved to be a great method of treatment. Bone marrow stem cells although looked promising source of donor cells, however questions arise on timing, dose and route of stem cell delivery. In another animal study, stem cells were injected into the rats one week after TBI. Stem cells transplantation into the carotid artery is simpler method that delivers directly to the brain. It also clued that stem cell treatment improves healing after TBI with significant recovery of function. Dr. Osanai and team wrote that the current study was the first one to track donor cells intra-arterially injected into the brain of living animals over 4 weeks.