Graphene and Ti ₃ C ₂ T _<i>x</i> MXene Nanomaterial-Infused Bioinks for Mechanical and Electrical Improvement of 3D Bioprinted Scaffolds

The precise control of bioink formulation, process parameters, and scaffold geometries has enabled some critical limitations of bioprinting to be overcome and has transformed the construction of functional 3-dimensional (3D) bioscaffolds for tissue engineering (TE). Current bioscaffolds fall short in producing functional tissue due to a lack of the physiological, mechanical, and electrical environments necessary for optimal cell development. In this study, we report the incorporation of the nanomaterial (NM) graphene/graphene oxide (GGO) and titanium carbide (Ti₃C₂T_<i>x</i> MXene) into an alginate-cellulose-based bioink to enhance printability and modify the physical properties of bioprinted scaffolds to better mimic physiological conditions. Our results indicate that incorporating Ti₃C₂T_<i>x</i> MXene nanoflakes into the alginate cellulose-based bioink from CELLINK improved the compressive Young's modulus by approximately 72% and enhanced the electrical conductivity by 0.39 S/m. The inclusion of GGO improved conductivity by 0.12 S/m but did not improve the compressive Young's modulus. Biocompatibility of the CELLINK bioink enhanced with NMs was demonstrated in mouse myoblast cells (C2C12), followed by live/dead confocal imaging, which showed greater than 95% viability for each ink. Our results suggest these electrically conductive NMs can be used to tune the physical properties of bioinks for 3D-bioprinted scaffolds specific to cell types and stimuli.