Collagen/pristine graphene as an electroconductive interface material for neuronal medical device applications

The growing clinical demand for electrical stimulation-based therapies requires the development of novel conductive biomaterials that balance conductivity, biocompatibility, and mechanical performance. Traditional conductive materials often induce scarring, due to their stiffness and poor biocompatibility, presenting challenges to their clinical translation. To address these issues, we report the development of an electroconductive pristine graphene-based (pG) composite material for central nervous system applications, consisting of type I collagen loaded with 60 wt% pG to yield conductivities (∼1.5 S/m) necessary for efficient electrical stimulation. Neurons and glial cells grown on composite films exhibited robust growth, and glial cells exhibited no change in inflammatory markers. Electrical stimulation of primary neurons on the composite enhanced neurite outgrowth, cellular viability and morphology compared to collagen controls. Finally, we demonstrated the versatility and potential applications of the composite material for neuronal medical device applications by fabricating a range of conductive, neural-interfacing structures, including porous scaffolds, microneedle arrays, and 3D-printed circuits for bioelectronics. These results show that CpG composites form a versatile neurotrophic platform that balances biocompatibility and physiologically relevant conductivity with robust mechanical properties that allow for the production of a range of next-generation neuroprosthetic devices.