Biocompatibility and efficacy of five-channel and eight-channel crosslinked urethane-doped polyester elastomers (CUPEs) as nerve guidance conduit for reconstruction of segmental peripheral nerve defect using rat model

Abstract

Introduction Peripheral nerve injury is common in clinical practice. The usual etiologies are penetrating injury, stretch, compression, crush and ischemia. Outcome of nerve injury depends on the etiology and also the management. Nerve defect is a challenging scenario. The current gold standard of managing a nerve defect is autologous nerve graft.

However, due to the selection of nerve graft and donor site morbidity, artificial nerve conduits are gaining popularity. However, there are drawbacks of single hollow conduit such as lack of internal support to prevent conduit collapse and inability so as to recreate the proper native spatial arrangement of cells and extracellular matrix within the conduit. In this study, the biocompatibility and efficacy of five-channel and eight-channel Crosslinked Urethane-doped Polyester Elastomers (CUPEs) as nerve guidance conduit will be evaluated through a rat model with reconstruction of segmental peripheral nerve defect.

Material and method Eighteen adult Sprague-Dawley rats were used. Tthey were randomly allocated to three groups: autograft group, five-channel conduit group and eight-channel conduit group with each consisted of six rats. A 10mm nerve defects were created at the right sciatic nerve. They were bridged with reverse autograft, 5-channel conduit and 8-channel conduit. After eight weeks the rats were euthanized and the reconstructed nerves were harvested for histomorphometric analysis.

Results All conduits showed regenerated nerve tissue inside. There was no collapse of the conduits. There were no severe tissue reaction or scarring near the reconstructed nerve. No neuroma was formed. Histomorphometric analysis showed nerve regeneration was enhanced with increasing number of channels inside conduit. There was overall drop in fiber density between proximal and distal segment among all groups.

Conclusions CUPE nerve guidance conduit is biocompatible and shows good nerve regeneration in reconstructing nerve defect.