3D conductive scaffolds as Neural Prostheses based on Carbon Nanotubes and Polypyrrole

Three-dimensional scaffolds for cellular organization need to enjoy a series of specific properties. On the one hand, the morphology, shape and porosity are critical parameters, and eventually re-lated with the mechanical properties. On the other hand, electrical conductivity is an important asset when dealing with electroactive cells, so it is a desirable property even if the conductivity values are not particularly high. Here, we construct 3D porous and conductive composites, where C8-D1A astrocytic cells were incubated to study their biocompatibility. The manufactured scaf-folds are composed exclusively of Carbon Nanotubes (CNTs), a most promising material to inter-face with neuronal tissue, and polypyrrole (PPy), a conjugated polymer demonstrated to reduce gliosis, improve adaptability and increase charge-transfer efficiency in brain-machine interfaces. We developed a new and easy strategy, based on the Vapor Phase Polymerization (VPP) tech-nique, where the monomer vapor is polymerized inside a sucrose sacrificial template containing CNT and an oxidant agent. After removing the sucrose template, a 3D porous scaffold was ob-tained whose physical, chemical and electrical properties were evaluated. The obtained scaffold showed very low density, high and homogeneous porosity, electrical conductivity and Young Modulus similar to the in vivo tissue. Its high biocompatibility was demonstrated even after 6 days of incubation, thus paving the way for the development of new conductive 3D scaffolds potentially useful in the field of electroactive tissues.