This study presents a novel approach for delivering water-insoluble cancer drugs using PEGylated nano-graphene oxide (NGO-PEG). Graphene, a 2D material, has shown promise in various applications, but its use in biological systems has been limited. Here, researchers synthesized and functionalized nanoscale graphene oxide (NGO) sheets with branched, biocompatible polyethylene glycol (PEG) to enhance their aqueous solubility and stability in physiological solutions. This PEGylated NGO (NGO-PEG) demonstrated a unique ability to attach and deliver aromatic, water-insoluble drugs, such as SN38, a camptothecin (CPT) analog. SN38 is a potent topoisomerase I inhibitor, but its clinical use is hindered by its poor water solubility. The study showed that NGO-PEG could complex with SN38 via non-covalent interactions, resulting in a highly soluble and potent drug delivery system. The NGO-PEG-SN38 complex exhibited excellent aqueous solubility and retained the high potency of free SN38. It was also more toxic than the FDA-approved SN38 prodrug, CPT-11. The researchers prepared graphene oxide by oxidizing graphite using a modified Hummer's method. They then sonicated the GO to make it into small pieces and conjugated a 6-armed PEG-amine star to the carboxylic acid groups on GO. The resulting PEGylated NGO showed excellent stability in biological solutions. The study also demonstrated that NGO-PEG could effectively load various water-insoluble, aromatic drugs, including different camptothecin analogs and Iressa (geftinib). The NGO-PEG-SN38 complex showed high potency in killing cancer cells, with an IC50 value of ~6nM for HCT-116 cells, which is 1000 times more potent than CPT-11. The study also found that plain NGO-PEG without drug loading was not toxic, suggesting that the PEGylated nanographene oxide sheets were not cytotoxic by themselves. The unique 2D shape and ultra-small size of NGO-PEG may offer interesting in vitro and in vivo behaviors, making it a promising material for biological applications.This study presents a novel approach for delivering water-insoluble cancer drugs using PEGylated nano-graphene oxide (NGO-PEG). Graphene, a 2D material, has shown promise in various applications, but its use in biological systems has been limited. Here, researchers synthesized and functionalized nanoscale graphene oxide (NGO) sheets with branched, biocompatible polyethylene glycol (PEG) to enhance their aqueous solubility and stability in physiological solutions. This PEGylated NGO (NGO-PEG) demonstrated a unique ability to attach and deliver aromatic, water-insoluble drugs, such as SN38, a camptothecin (CPT) analog. SN38 is a potent topoisomerase I inhibitor, but its clinical use is hindered by its poor water solubility. The study showed that NGO-PEG could complex with SN38 via non-covalent interactions, resulting in a highly soluble and potent drug delivery system. The NGO-PEG-SN38 complex exhibited excellent aqueous solubility and retained the high potency of free SN38. It was also more toxic than the FDA-approved SN38 prodrug, CPT-11. The researchers prepared graphene oxide by oxidizing graphite using a modified Hummer's method. They then sonicated the GO to make it into small pieces and conjugated a 6-armed PEG-amine star to the carboxylic acid groups on GO. The resulting PEGylated NGO showed excellent stability in biological solutions. The study also demonstrated that NGO-PEG could effectively load various water-insoluble, aromatic drugs, including different camptothecin analogs and Iressa (geftinib). The NGO-PEG-SN38 complex showed high potency in killing cancer cells, with an IC50 value of ~6nM for HCT-116 cells, which is 1000 times more potent than CPT-11. The study also found that plain NGO-PEG without drug loading was not toxic, suggesting that the PEGylated nanographene oxide sheets were not cytotoxic by themselves. The unique 2D shape and ultra-small size of NGO-PEG may offer interesting in vitro and in vivo behaviors, making it a promising material for biological applications.