Role of Graphene Nano-Composites in Cancer Therapy: Theranostic Applications, Metabolic Fate and Toxicity Issues

Graphene and its modified nano-composites have gained much attention in recent times in cancer therapy as nanotheranostics due to low production cost, ease in synthesis and physicochemical properties (ultra-large surface area with planar structure and π-π conjugation with the unsaturated and aromatic drugs/biomolecules) being favorable for multiple payloads and drug targeting. Yet, graphene nano-composites are a relatively new and rapid development. The adoption of graphene nano-composites in cancer nanobiomedicine research raises questions about in vivo metabolism and disposition as well as biological interaction and safety profile of these nano-particles. Limited in-vitro and in-vivo findings are available in literature, indicating the inconsistencies about the factors affecting in-vivo bio-interaction and toxicity. Presently, there is a lack of anticipated biodistribution and toxicity pattern of graphene. It appears that surface functionalization, biocompatible coating, and size are the key factors in determining the metabolic fate of graphene nano-composites. In-vitro and in-vivo toxicity data suggests that graphene nano-composites exhibit dose and size dependent toxicity. This review summarizes up-to-date research outcome of this promising inorganic nanomaterial for cancer therapy. Moreover, the metabolic fate and toxicity issues of graphene and its nano-composites shall also be discussed in detail.