Tough and conductive hybrid graphene-PVA: Alginate fibrous scaffolds for engineering neural construct

The aim of this study was to develop a hybrid Gr nanosheets-sodium alginate (SA)/polyvinyl alcohol (PVA) (Gr-AP) fibrous scaffold with exceptional toughness and electrical conductivity for nerve tissue engineering. Furthermore, the effects of Gr concentration (0, 0.5, 1, 2 and 5 wt%) on the electrical, mechanical, physical and biological properties as well as degradation date of scaffolds were evaluated. Results demonstrated that, compared to AP scaffold, the toughness of hybrid Gr-AP scaffold containing 1 wt% Gr considerably improved (4-fold) which attributed to the strong interfacial interactions between Gr nanosheets and AP matrix. Furthermore, 1 wt% Gr in AP scaffolds acted as electrical nanobridges leading to improved electrical conductivity of the pure AP scaffold. To estimate cell response dependence on the substrate properties, the PC12 cells were cultured on Gr-AP scaffolds. Results revealed the potentials of Gr content scaffolds to support attachment and spreading of PC12 cells. Moreover, MTT assay also confirmed that after 7 days of culture, the hybrid scaffold consisting of 1 wt% Gr nanosheets significantly promoted cell proliferation compared to AP scaffold (1.4-fold). Overall, our findings demonstrated that Gr-AP scaffolds exhibited superior electrical and mechanical properties with enhanced PC12 cell interaction. It is envisioned that the offered hybrid Gr-AP scaffolds might have great potential to develop the devices for peripheral nerve regeneration. However, further biological studies along with electrical stimulation are necessary to evaluate the role of hybrid Gr-AP scaffolds on the nerve regeneration.