In It for the Long Haul: The Cytocompatibility of Aged Graphene Oxide and Its Degradation Products.

Synthetic biomaterials are poised to transform medicine; however, current synthetic options have yet to ideally recapitulate the desirable properties of native tissue. Thus, the development of new synthetic biomaterials remains an active challenge. Due to its excellent properties, including electrical conductivity, water dispersibility, and capacity for functionalization, graphene oxide (GO) holds potential for myriads of applications, including biological devices. While many studies have evaluated the compatibility of freshly prepared GO, understanding the compatibility of GO as it ages in an aqueous environment is crucial for its safe implementation in long-term biological applications. This is a critical disconnect, as GO has been shown to undergo an autodegradation pathway in aqueous conditions, dynamically changing its composition and structure while producing degradation products. Thus, the long-term cytocompatibility of GO is investigated by "aging" GO over time in water and accelerating aging and decomposition via sonication. While age affects the composition and size of GO, it has no effect on cellular vitality and does not alter subcellular structures or DNA melting. Overall, GO is cytocompatible throughout the process of aging, beginning to demonstrate that GO may be utilized for long-term in vivo applications such as implanted tissue engineered scaffolds or biosensors.