Hierarchical thermoplastic rippled nanostructures regulate Schwann Cell adhesion, morphology and spatial organization

Periodic ripples are a variety of anisotropic nanostructures that can be realized by ion beam irradiation on a wide class of solid surfaces. Only few authors have investigated these surfaces for tuning the response of biological systems, probably because it is challenging to directly produce them in materials that well sustain long-term cellular cultures. Here, hierarchical rippled nanotopographies with lateral periodicity of ∽300 nm are produced from a gold-irradiated germanium mold in polyethylene terephthalate (PET), a biocompatible polymer approved by the US Food and Drug Administration for clinical applications, by a novel three-steps embossing process. The effects of nano-ripples on Schwann Cells (SCs) are studied in view of their possible use for nerve-repair applications. Data demonstrate that nano-ripples can enhance short-term SC adhesion and proliferation (3-24h from seeding), drive their actin cytoskeleton spatial organization and sustain long-term cell growth. Notably, SCs orient perpendicularly with respect to the nanopattern lines. These results provide information about the possible use of hierarchical nano-rippled elements for nerve-regeneration protocols.