Intra-arterial delivery of human bone marrow mesenchymal stem cells is a safe and effective way to treat cerebral ischemia in rats.

Cerebral ischemic stroke is a very common condition that can cause death and disability. Studies have confirmed that stem cells have therapeutic effects if administered after a stroke. There is still a great deal of debate regarding the best route for cell transplantation. Intravascular delivery is the most commonly used one. In this study, the therapeutic effects of bone marrow stem cells (BMSCs) delivered by intra-arterial (IA) and intravenous (IV) injection in a rat transient middle cerebral artery occlusion model (MCAO) are compared. Histological analysis demonstrated that the IA route bypasses the pulmonary system and directs the cells to the ischemic parts of the brain more efficiently. The BMSCs delivered via the IA route promoted angiogenesis and improved functional recovery. The cerebral blood flow (CBF) of the rats was monitored during the IA injection process. No reduction in CBF or microstrokes was detected. Brain perfusion and metabolism, as evaluated by SPECT and PET, were better in rats treated with cells delivered via IA. Results showed that the IA route is a safe and effective way to transplant hBMSCs. This manuscript is published as part of the International Association of Neurorestoratology (IANR) special issue of Cell Transplantation.