Blood brain barrier (BBB) permeabilizers, such as mannitol, can facilitate the entry of stem cells from the periphery to the stroke brain. It is unknown whether BBB permeation in the chronic stage of the disease still facilitates the entry of stem cells from the periphery to the injured brain. Evidence herein shows BBB permeation in the chronic stage of stroke assisted in the entry of stem cells from the periphery to the stroke brain. Stroke models treated with human umbilical cord stem cells (hUCBC) only (2 million viable cells), mannitol or a combination. Results revealed that hUCBC alone or combined with mannitol displayed significant behavioral and histological deficits compared to control animals, with the HUCBC-mannitol combined treatment showing improvements over hUCBC only treatments in brain cell survival in the peri-infarct area. BBB permeation in chronic stroke also lowers the effective stem cell dose necessary to improve functional outcomes.
