In the last decade, the use of photolithography for the fabrication of structured substrates with controlled morphological patterns that are able to interact with cells at micrometric and nanometric size scales is strongly growing. A promising simple and versatile microfabrication method is based on the physical mass transport induced by visible light in photosensitive azobenzene-containing polymers (or azopolymers). Such light-driven material transport produces a modulation of the surface of the azopolymer film, whose geometry is controlled by the intensity and the polarization distributions of the irradiated light. Herein, two anisotropic structured azopolymer films have been used as substrates to evaluate the effects of topological signals on the in vitro response of human mesenchymal stem cells (hMSCs). The light-induced substrate patterns consist of parallel microgrooves, which are produced in a spatially confined or over large-scale areas of the samples, respectively. The analysis of confocal optical images of the in vitro hMSC cells grown on the patterned films offered relevant information about cell morphology—i.e., nuclei deformation and actin filaments elongation—in relation to the geometry and the spatial extent of the structured area of substrates. The results, together with the possibility of simple, versatile, and cost-effective light-induced structuration of azopolymers, promise the successful use of these materials as anisotropic platforms to study the cell guidance mechanisms governing in vitro tissue formation.

Over the past two decades, the development of nerve guide conduits (NGCs) has gained much attention due to the impellent need to find innovative strategies to take care of damaged or degenerated peripheral nerves in clinical surgery. In this view, significant effort has been spent on the development of high-performance NGCs by different materials and manufacturing approaches. Herein, a highly versatile and easy-to-handle route to process 3D porous tubes made of chitosan and gelatin to be used as a nerve guide conduit were investigated. This allowed us to fabricate highly porous substrates with a porosity that ranged from 94.07 ± 1.04% to 97.23 ± 1.15% and average pore sizes—estimated via X-ray computed tomography (XCT) reconstruction and image analysis—of hundreds of microns and an irregular shape with an aspect ratio that ranged from 0.70 ± 0.19 to 0.80 ± 0.15 as a function of the chitosan/gelatin ratio. More interestingly, the addition of gelatin allowed us to modulate the mechanical properties, which gradually reduced the stiffness—max strength from 0.634 ± 0.015 MPa to 0.367 ± 0.021 MPa—and scaffold toughness—from 46.2 kJ/m³ to 14.0 kJ/m³—as the gelatin content increased. All these data fall into the typical ranges of the morphological and mechanical parameters of currently commercialized NGC products. Preliminary in vitro studies proved the ability of 3D porous tubes to support neuroblastoma cell (SH-SY5Y) adhesion and proliferation. In perspective, the proposed approach could also be easily implemented with the integration of other processing techniques (e.g., electrospinning) for the design of innovative bi-layered systems with an improved cell interface and molecular transport abilities.