Biocompatibility of different graphene oxide coatings on polymers

Graphene Oxide has great potential to be used in tissue engineering applications. However, its stability in wet environment is questionable. Spin, dip and plasma cross-linked graphene oxide (GO) coatings of polymers (PEEK and PET) were used in a cell study to establish stability and biocompatibility. The different coatings procedure produced surfaces with different topography and functionality. All the coatings were stable in wet cell culture environment. Despite the fact that most of the coatings were highly oxidized, as measured by XPS, with high carboxyl groups relative concentration, they showed minimal toxic effect on the examined cell line (C2C12 myoblast). The effect of oxidative stress was not evident on this particular cell line as a typical fusiform shape and adherence on the surface were detected for all samples. With the exception of the GO dip coated PEEK sample, all other coatings showed high cell proliferation, comparable to the positive control. This reflects on the stability of GO dip coating process and suggests that coating stabilization is necessary for biomedical applications. We observed (using AFM) a higher rates of ripples and wrinkles in the spin and dip GO coated PEEK (but not PET) which led to observable myogenic differentiation, imaged by SEM.