Conductive polyurethane/PEGylated graphene oxide composite for 3D-printed nerve guidance conduits

Abstract

Conductive polymeric nanocomposites have made significant contributions in nerve regeneration. To this aim, the best results are obtained by using nerve guidance conduits (NGCs) with conductive, bio-compatible, bio-degradable tubes as well as special topographical features. In this study, biodegradable, conductive, solvent-free polyurethane/PEGylated graphene oxide (PU/PEG-GO) composites were synthesized and successfully 3D printed into flexible nerve conduits with different precise geometries, such as hollow, porous, and grooved tubes, using stereolithography. The composite containing 5% PEG-GO showed the highest tensile stress (3.51 ± 0.54 MPa), tensile strain at break (∼170%), and conductivity (1.1 × 10−3 S/cm) with the lowest contact angle of 72° attributing to the strong interfacial interactions between PEG-GO nanosheets and the PU matrix. Moreover, the PU/PEG-GO 5% exhibited higher compression strength compared with pure PU and showed appropriate enzymatic degradation after 6 weeks, which is expected to last sufficiently for an efficient nerve regeneration. Altogether the 3D-printed, conductive, biodegradable, and flexible PU/PEG-GO 5% conduit with precise geometry has potential as NGCs for peripheral nerve regeneration.