3D electrohydrodynamic printing of highly aligned dual-core graphene composite matrices

The aim of this study was to develop an EHD printing method to fabricate graphene-loaded polycaprolactone (PCL)/polyethylene oxide (PEO) dual-core matrices. Graphene was incorporated in shell PCL components, while gelatin and dopamine hydrochloride (DAH) were encapsulated in two PEO cores to enhance biocompatibility of graphene-loaded matrices. Furthermore, the effect of PEO concentration on dual-core fiber formation was evaluated. The influence of process parameters (applied voltage, inner flow rate, outer flow rate and X-Y-Z collector stage speed) on dual-core fiber morphology was evaluated. Our findings show graphene-loaded structures to possess two inner cores and increasing graphene content yields matrices with smoother surfaces, causing a slight reduction in their contact angle behavior. Furthermore, the addition of graphene to matrices results in reduced elasticity. DAH release from matrices comprising various graphene concentrations showed no significant difference and drug release mechanism was diffusion based. In vitro biological tests indicate resulting graphene-loaded dual-core matrices exhibit good biocompatibility and also improve PC12 cell migration. The findings suggest matrices to have potential applications in nerve restoration and regeneration.