The aim of this study is to evaluate the functional and cell biological applicability of a two-ply nerve guide constructed of a PLLA/PCL (i.e. poly-L-lactide and poly-epsilon-caprolactone) copolymer. To do so, we performed a cytotoxicity test, a subcutaneous biodegradation test and an in situ implantation study in the sciatic nerve of the rat. The nerve guide copolymer was found to be non-toxic, according to ISO/EN standards, and it showed a mild foreign body reaction and complete fibrous encapsulation after implantation. Onset of biodegradation of the inner layer was seen after one month of implantation. After 1 8 months of implantation complete fragmentation was observed, as well as a secondary inflammatory response. characterized by foreign body giant cell activity and phagocytosis of polymer debris. Recovery of both motor and sensory nerve function was observed in all nerve guides.