2D nanomaterials, particularly graphene, offer many fascinating physicochemical properties that have generated exciting visions of future biological applications. In order to capitalize on the potential of 2D nanomaterials in this field, a full understanding of their interactions with biointerfaces is crucial. The uptake pathways, toxicity, long-term fate of 2D nanomaterials in biological systems, and their interactions with the living systems are fundamental questions that must be understood. Here, the latest progress is summarized, with a focus on pathogen, mammalian cell, and tissue interactions. The cellular uptake pathways of graphene derivatives will be discussed, along with health risks, and interactions with membranes-including bacteria and viruses-and the role of chemical structure and modifications. Other novel 2D nanomaterials with potential biomedical applications, such as transition-metal dichalcogenides, transition-metal oxide, and black phosphorus will be discussed at the end of this review.

Schematic representation of synergistic action of electrostatic interactions of polyglycerol sulfate and conjugated aliphatic chains to the surface of nG-PGS.

Multidrug resistance (MDR), which leads tumors resistance to traditional anticancer drugs, can cause the failure of chemotherapy treatments. Herein, we present a new way to overcome this problem using smart multifunctional graphene-based drug delivery systems which can target subcellular organelles and show synergistic hyperthermia and chemotherapy. Mitochondria-targeting ligands are conjugated onto the doxorubicin-loaded, polyglycerol-covered nanographene sheets to actively accumulate them inside the mitochondria after charge-mediated cellular internalization. Upon near-infrared (NIR) irradiation, adenosine triphosphate (ATP) synthesis and mitochondrial function were inhibited and doxorubicin released into the cellular interior. The hyperthermia-accelerated drug release led to a highly selective anticancer efficiency, confirmed by in vitro and in vivo experiments.

Multidrug resistance (MDR), which leads tumors resistance to traditional anticancer drugs, can cause the failure of chemotherapy treatments. Herein, we present a new way to overcome this problem using smart multifunctional graphene‐based drug delivery systems which can target subcellular organelles and show synergistic hyperthermia and chemotherapy. Mitochondria‐targeting ligands are conjugated onto the doxorubicin‐loaded, polyglycerol‐covered nanographene sheets to actively accumulate them inside the mitochondria after charge‐mediated cellular internalization. Upon near‐infrared (NIR) irradiation, adenosine triphosphate (ATP) synthesis and mitochondrial function were inhibited and doxorubicin released into the cellular interior. The hyperthermia‐accelerated drug release led to a highly selective anticancer efficiency, confirmed by in vitro and in vivo experiments.

Enzyme-functionalized, doxorubicin-loaded, self-degradable graphene nanoplatforms show high antitumor activity, due to synergistic photothermal- and chemotherapy along with neutrophil-like activity.

A new method for top‐down, one‐pot, gram‐scale production of high quality nanographene by incubating graphite in a dilute sodium hypochlorite solution at only 40 °C is reported here. The produced sheets have only 4 at% oxygen content, comparable with nanographene grown by chemical vapor deposition. The nanographene sheets are covalently functionalized using a nondestructive nitrene [2+1] cycloaddition reaction that preserves their π‐conjugated system. Statistical analyses of Raman spectroscopy and X‐ray photoelectron spectroscopy indicate a low number of sp3 carbon atoms on the order of 2% before and 4% after covalent functionalization. The nanographene sheets are significantly more conductive than conventionally prepared nanographene oxide, and conductivity further increases after covalent functionalization. The observed doping effects and theoretical studies suggest sp2 hybridization for the carbon atoms involved in the [2+1] cycloaddition reaction leading to preservation of the π‐conjugated system and enhancing conductivity via n‐type doping through the bridging N‐atom. These methods are easily scalable, which opens the door to a mild and efficient process to produce high quality nanographenes and covalently functionalize them while retaining or improving their physicochemical properties.

Fluorous biphasic systems use the temperature-sensitive miscibility of fluorinated materials in nonfluorous solutions as a means to control reaction systems and easily separate catalysts or other compounds from a mixture. We present perfluoroalkylated nanographene as a viable platform for photohomogenization and recycling of fluorous-tagged catalysts. The photothermal properties of graphene materials, particularly in the near-infrared range, enable comparatively fast activation time and simplify the recycling of catalysts thanks to the easy separation of the solid fluorinated graphene phase from most solvents by centrifugation. A fluorinated phosphine catalyst was used in a modified, catalyst-regenerative Appel reaction as a model system. The catalyst could be successfully recovered and reused for at least 10 cycles with minimal loss of yield.

In this work, we report a new method for the synthesis of graphene oxide (GO) using cyanuric chloride as a non-corrosive oxidizing agent.