Stereolithography 3D printing of microgroove master moulds for topography induced nerve guidance conduits

Patients who have peripheral nerve damage from trauma or disease can suffer lifelong disability. Current interventions such as nerve allografts are inadequate due to limited availability of tissue and donor-site morbidity. Commercial nerve guidance conduits aim to bridge the damaged nerve gap and restore function. However, typically they lack cell instructive guidance cues to promote directed regeneration. Tissue engineered nerve guidance conduits that utilise micro- and nanotopographical architectures have been demonstrated to direct cell behaviour and contact guidance. This study uses projection micro-stereolithography based three-dimensional (3D) printing to fabricate microgrooved (10-30 µm) master moulds to produce polydimethylsiloxane (PDMS) moulds and solvent cast polycaprolactone and polylactic acid films. The polymer microgroove were successfully fabricated and were able to be formed into tubular nerve guidance conduits. The surface morphology, roughness, wettability, and thermal properties of the films were characterised. The role of microgroove architecture on SH-SY5Y cells was evaluated showing improved cell proliferation and orientation on the microgroove topographies. This facile 3D printing approach is promising for the fabrication of nerve guidance conduits with topographical guidance cues as it avoids the use of photolithographic techniques. Thus, providing an alternative that is simpler, faster, cheaper, and offers greater design freedom.