 Polysialic acid (PSA) is a relatively new biocompatible and bioresorbable material for artificial nerve conduits.It is a homopolymer of α2,8-linked sialic acid residues and a dynamically regulated posttranslational modification of the neural cell adhesion molecule (NCAM).Recent studies have demonstrated that polysialylated NCAM (polySia-NCAM) promotes regeneration in the motor system.