Minimally invasive delivery of stem cells for spinal cord injury: advantages of the lumbar puncture technique

Abstract

Object. Stem cell therapy has been shown to have considerable therapeutic potential for spinal cord injuries (SCIs); however, most experiments in animals have been performed by injecting cells directly into the injured parenchyma. This invasive technique compromises the injured spinal cord, although it delivers cells into the hostile environment of the acutely injured cord. In this study, the authors tested the possibility of delivering stem cells to injured spinal cord by using three different minimally invasive techniques. Methods. Bone marrow stromal cells (BMSCs) are clinically attractive because they have shown therapeutic potential in SCI and can be obtained in patients at the bedside, raising the possibility of autologous transplantation. In this study transgenically labeled cells were used for transplantation, facilitating posttransplantation tracking. Inbred Fisher-344 rats received partial cervical hemisection injury, and 2 × 106 BMSCs were intravenously, intraventricularly, or intrathecally transplanted 24 hours later via lumbar puncture (LP). The animals were killed 3, 10, or 14 days posttransplantation, and tissue samples were submitted to histochemical and immunofluorescence analyses. For additional comparison and validation, lineage restricted neural precursor (LRNP) cells obtained from E13.5 rat embryos were transplanted via LP, and these findings were also analyzed. Conclusions. Both BMSCs and LRNP cells home toward injured spinal cord tissues. The use of LP and intraventricular routes allows more efficient delivery of cells to the injured cord compared with the intravenous route. Stem cells delivered via LP for treatment of SCI may potentially be applicable in humans after optimal protocols and safety profiles are established in further studies.