Influence of glial growth factor and Schwann cells in a bioresorbable guidance channel on peripheral nerve regeneration

Using an established rat peripheral nerve regeneration model, we investigat ed the role of glial growth factor (GGF) in nerve regeneration in combinati on with a novel bioresorbable poly(lactic-co-glycolic) acid (PLGA) guide in vivo. Schwann cells, established from a 1-cm segment of excised rat sciati c nerve, were isolated and seeded onto nerve guides with or without GGF (n = 24/group). Living nerve guides were re-established in these animals, and nerve regeneration was assessed over a period of 12 weeks. Histological stu dies revealed a reduction in the total axon count and the number of myelina ted axons in the presence of exogenously added Schwann cells compared to sa line controls. In contrast, the addition of GGF alone enhanced the total nu mber of axons and significantly increased the number of blood vessels. Alth ough combining GGF with Schwann cells negated the enhanced numbers of axons and blood vessels seen with GGF alone, this combination resulted in the hi ghest myelination index and the fastest conduction velocities recorded. The PLGA guide material did not trigger any histologically detectable host res ponse and was permissive for nerve regeneration in this animal model. The r esults from this study demonstrate the potential utility of this guide in v ivo and establish a promotional role for GGF in nerve regeneration.