Migration and distribution of bone marrow stromal cells in injured spinal cord with different transplantation techniques.

Objective: To study the regularity of migration and distribution of bone marrow stromal cells (BMSCs) in injured spinal cord with intradural space transplantation.

Methods: Forty Wistar rats were randomly assigned into 4 groups. The spinal cord injury model was prepared according to the modified Allen method. BMSCs were labeled by CM-Dil. And 5.0 multiply 10(6) cells were transplanted by different channels including intraventricular injection (Group A),injured spinal cord intrathecally injection (Group B), remote intrathecally injection at the L(3)-L(4) level (Group C), and intravenous injection (Group D). Spinal cord was dissected at 24 hours, 1, 2, 3 and 4 weeks after transplantation. Sections of 4 micromolar were cut on a cryostat and observed under fluorescence microscopy.

Results: No fluorescence was observed 24 hours after transplantation in spinal cord injury parenchyma except Group B. One week later, BMSCs in Groups A and C began to migrate to the injured parenchyma; 2-4 weeks later, BMSCs penetrated into the injured parenchyma except Group D. The number of BMSCs decreased at 3-4 weeks after transplantation. The number of cells in Group B decreased faster than that of Groups A and C.

Conclusions: BMSCs transplanted through intraventricular injection, injured spinal cord intrathecally injection and remote intrathecal injection could migrate to the injured parenchyma of spinal cord effectively. The number of BMSCs migrated into injured spinal cord parenchyma is rare by intravenous injection.