Graphene-based nanosheets (GNS) are atomic-thickness monolayers of hexagonally arranged, graphite-derived
carbon atoms that may be composed of graphene, graphene oxide, or reduced graphene oxide. They have attracted tremendous
interest for their potential in pharmaceutical applications, due to their unique physical, chemical, and mechanical
properties GNS exhibit highly uniform surface areas and may have hydroxyl (-OH), epoxide (-O-), and carboxyl functional
groups at their basal surfaces and plane edges, depending on their oxidized and reduced surface properties. GNS
show high-level optical absorption of near infrared (NIR) light and elevate the temperature of nearby environments. Furthermore,
they can be loaded with anticancer drugs via hydrophobic interactions, π−π stacking, or electrostatic binding.
Given these properties, GNS can be used in chemotherapy, photodynamic therapy, photothermal therapy, and theranostics.
However, although GNS appear to have far-reaching potential in the field of biomedical research, their widespread
pharmaceutical application has been limited by issues such as poor stability in physiological buffers, undefined mechanisms
of cellular uptake, toxicity problems, and a lack of standard preparation methods. Here, we review the current
pharmaceutical applications of GNS, focusing on chemotherapy, phototherapy, combo therapy and theranostic applications
with challenging issues.