Olfactory Stem Cells for the Treatment of Spinal Cord Injury: Isolation, Purification and Behaviour in a Plasma Clot Matrix

Abstract

Cell therapies represent promising strategies to improve neurological functions after spinal cord injury (SCI). Olfactory mucosa (OM) might be an attractive source of multipotent cells for neuroregeneration because olfactory stem cells (OSCs) are resident. The regenerative capacity of OSCs has been demonstrated in animal models and some clinical case reports. Up to now, there are no standard methods for purification, characterization, and delivery of OSCs to the injury site. However, purification and characterization of the grafted cells are prerequisites for clinical use to ensure maximum safety for the patients. In this study, we isolated and purified OSCs from human OM using the neurosphere assay. Subsequently, the cells were characterized, and the behavior of purified OSCs in a plasma clot was investigated. Our study demonstrated that isolated cells from OM form neurospheres, which cells are positive for CD105 (98%) and CD90 (99%) and negative for Epcam (<1%) and MUC5AC (<1%). Purified OSCs were positive for Nestin, CD44 as well as GFAP and showed a lack of CD34 and CD45 expression. OSCs differentiated into neuron-like cells expressing ß-III tubulin. However, differentiation into adipocytes, chondrocytes or osteoblast could not be observed. In addition, OSCs stayed viable and were able to proliferate within the plasma clot. These results highlight OSC as a candidate for autologous transplantation in combination with the plasma clot as a cell carrier in SCI and neurodegenerative disease.