Graphene trapped silk scaffolds integrate high conductivity and stability

Abstract

Incorporation of highly conducting graphene into electrospun biodegradable polymer mats is very promising for the fabrication of electroactive flexible scaffolds toward neural tissue engineering. However, the direct assembly of graphene onto electrospun polymer fibers for preparing stable conducting scaffolds remains a critical challenge due to the inertness of graphene. To overcome this issue, a one-pot assembly approach was developed to trap graphene inside electrospun mats of regenerated silk fibroin (RSF) by applying its ethanol-treatment driven supercontract. This approach is simple, direct, and controllable, loads only a small amount of graphene, and achieves high conductivity for scaffolds (a minimum resistance of (54.9 ± 20.3) Ω/sq). This ensures weak interference on the softness and biodegradability of graphene trapped RSF scaffolds. Thus, the prepared graphene functionalized RSF scaffold remains highly conductive and stable even with ultrasonic washing. It promotes cell spreading and differentiation, and significantly stimulates the neurite outgrowth by 74.5%, while applying an optimized constant electrical potential, thus indicating it as an ideal candidate as electroactive scaffold for tissue engineering. The application of graphene trapped electrospun polymer mats can be extended to electro-tuned tissue engineering, skin electronics, wearable sensors, and e-textiles due to its combination of flexibility, portability, and electrical conductivity.