Graphene oxide (GO) has attracted more and more attention as a promising nanomaterial in biomedical research and applications. In this study, we explore the ability of GO as nanocarrier for synthetic DNA strands. Immunostimulatory CpG oligodeoxynucleotides (ODNs) are attached to Poly-l-Lysine (PLL) functionalized, polydisperse GO, or uniform small GO (sGO) nanosheets. Both types of GO-CpG ODN nanoconjugates can be delivered into murine Raw264.7 macrophages and possess immunostimulatory activity, while sGO-CpG appears to be a more efficient stimulator. In addition, sGO-CpG nanosheets exhibit higher cellular uptake but better biocompatibility compared to the larger GO-CpG counterpart. Furthermore, PLL functionalized sGO-CpG has higher immunostimulatory activity than azide functionalized sGO-CpG. Together, our studies provide evidence that sGO can be utilized as an ideal intracellular nanocarrier for synthetic single-stranded DNA, and sGO-PLL-CpG conjugates may serve as a potential proinflammatory therapeutic tool.Keywords: CpG ODN; graphene oxide; immunostimulatory activity; nanocarrier; uniform small;

Dexamethasone (DEX) is a well-known anti-inflammatory drug, whose widespread clinical use is nevertheless restricted by its serious side effects. By conjugation of DEX with C60, we found that this nanomedicine retained the anti-inflammatory activity of DEX while reducing side effects in the animal model. In mouse thymocytes, the CCK-8 assay showed that the cytotoxicity of DEX–C60 was significantly lower than that of free DEX. Flow cytometric studies revealed that incubation with DEX–C60 induced much less apoptotic thymocytes. Interestingly, such reduced cytotoxicity and apoptosis were not observed when equal moles of free C60 and free DEX were coincubated with thymocytes, suggesting that the conjugation alters the signal pathway of DEX. Indeed, we found that the binding of DEX–C60 and a glucocorticoid receptor (GR) was partially blocked in the thymocytes, which resulted in down-regulation of several apoptosis-related genes. These findings help understand the mechanism of beneficial effects of this new nanomedicine, DEX–C60, and promote its clinical applications.Keywords: apoptosis; C60; dexamethasone; glucocorticoid receptor; thymocytes;