Spinal cord injuries usually have a large cavity. In order to get axons to regenerate across these cavities a bridge is needed.
The best cells for bridge-building are Schwann cells, because they are easy to get from patients and because they support excellent axon regeneration.
The problem is that Schwann cells will not mix with astrocytes (the connective tissue cells of the spinal cord), so the bridges will not integrate with the spinal cord.
We have been studying the interactions between Schwann cells and astrocytes, finding why they will not mix and how to get them to integrate. Proteoglycans, Ephs/ephrins and cadherins are involved.
Afshari FT, Kwok JC, White L, Fawcett JW (2010) Schwann cell migration is integrin-dependent and inhibited by astrocyte-produced aggrecan. Glia 58:857-869.
Afshari FT, Kwok JC, Fawcett JW. Astrocyte-produced ephrins inhibit schwann cell migration via VAV2 signaling. J Neurosci 2010; 30: 4246-4255.