Construction and characterization of conductive collagen/multiwalled carbon nanotube composite films for nerve tissue engineering

Currently, a growing number of biomaterials have been evaluated to be beneficial to the application of neural tissue engineering. However, their deficient mechanical and electrical properties limit their further application, especially for nerve regeneration. Therefore, the combination of biological matrix and conductive materials has been applied to meet the requirements for nerve tissue engineering. In this work, conductive collagen (COL)/multiwalled carbon nanotube (MWNT) composite films with different MWNT concentrations were developed by the solvent–evaporation method. The effects of rigid MWNT on the structure, mechanical, thermal, and electrical properties of the flexible COL-based film were evaluated. The evaluation of mechanical properties revealed that the tensile strength of the COL/MWNT composite films was almost eight times as high as that of the pure COL film. The electrical property assessment demonstrated that the electrical conductivity of COL/MWNT-0.25% reached 0.45 S/cm, meeting the electrical stimulation conditions required for nerve growth. Furthermore, the cell viability assays revealed that the COL/MWNT composite films were non-cytotoxic and appropriate for cell growth. Our work proved that the conductive COL/MWNT composite films exhibited great potential for nerve tissue engineering application, which provided a novel self-electrical stimulated platform for the treatment of neural injuries.