Hair Follicle-Associated Pluripotent (HAP) Stem Cells in Gelfoam® Histoculture for Use in Spinal Cord Repair.

The stem cell marker, nestin, is expressed in the hair follicle, both in cells in the bulge area (BA) and the dermal papilla (DP). Nestin-expressing hair follicle-associated-pluripotent (HAP) stem cells of both the BA and DP have been previously shown to be able to form neurons, heart muscle cells, and other non-follicle cell types. The ability of the nestin-expressing HAP stem cells from the BA and DP to repair spinal cord injury was compared. Nestin-expressing HAP stem cells from both the BA and DP grew very well on Gelfoam®. The HAP stem cells attached to the Gelfoam® within 1 h. They grew along the grids of the Gelfoam® during the first 2 or 3 days. Later they spread into the Gelfoam®. After transplantation of Gelfoam® cultures of nestin-expressing BA or DP HAP stem cells into the injured spinal cord (including the Gelfoam®) nestin-expressing BA and DP cells were observed to be viable over 100 days post-surgery. Hematoxylin and eosin (H&E) staining showed connections between the transplanted cells and the host spine tissue. Immunohistochemistry showed many Tuj1-, Isl 1/2, and EN1-positive cells and nerve fibers in the transplanted area of the spinal cord after BA Gelfoam® or DP Gelfoam® cultures were transplanted to the spine. The spinal cord of mice was injured to effect hind-limb paralysis. Twenty-eight days after transplantation with BA or DP HAP stem cells on Gelfoam® to the injured area of the spine, the mice recovered normal locomotion.