Fabrication of a 3D Printed PCL Nerve Guide: In Vitro and In Vivo Testing.

Nerve guides are medical devices designed to guide proximal and distal ends of injured peripheral nerves in order to assist regeneration of the damaged nerves. We produced a 3D-printed polycaprolactone (PCL) nerve guide using an aligned gelatin-poly(3-hydroxybutyrate-co-3-hydroxyvalerate) electrospun mat, seeded with PC12 and Schwann cells (SCs). During characterization with microCT and SEM porosity (55%), pore sizes (675 ± 40 μm), and fiber diameters (382 ± 25 μm) were determined. Electrospun fibers had degree of alignment of 7°, indicating high potential for guidance. On Day 14, PC12 cells migrated from proximal to distal end of nerve guide when SCs were seeded on the guide. After 28 days, over 95% of PC12 were alive and aligned. PC12 cells expressed early differentiation marker beta-tubulin 10 times more than late marker NeuN. In a 10 mm rat sciatic nerve injury, functional recovery evaluated by using static sciatic index (SSI) was observed in mat-free guides and guides containing mat and SCs. Nerve conduction velocities were also improved in these groups. Histological stainings showed tissue growth around nerve guides with highest new tissue organization being observed with mat and cell-free guides. These suggest 3D-printed PCL nerve guides have significant potential for treatment of peripheral nerve injuries. This article is protected by copyright. All rights reserved.