Delivery of transgenically modified adult bone marrow cells to the rodent central nervous system

A major challenge in the treatment of neurological disorders is the effective delivery of molecules into the CNS and, more so, to the lesion site. The blood-brain barrier restricts the delivery of therapeutic molecules into the CNS when injected intravenously. This difficulty is further compounded by the short half-life of certain therapeutic agents. Organ-targeted protein delivery could circumvent these difficulties, provided that the corresponding cDNA can be delivered and expressed in the target tissue effectively and safely. Recent studies from a number of laboratories indicate that a subset of adult bone marrow cells home to the CNS among other organs and can be engineered to deliver and express therapeutic proteins into the CNS. This article, which is focused on work from the authors' research, reviews the opportunities and difficulties presented by this approach.