In Vivo Biodistribution and Toxicology of Carboxylated Graphene Quantum Dots

Abstract

Photoluminescent graphene quantum dots (GQDs) have fascinating optical and electronic properties with numerous promising applications in biomedical engineering. In this work, we first studied the in vivo biodistribution and the potential toxicity of carboxylated photoluminescent GQDs. KB, MDA-MB231, A549 cancer cells, and MDCK normal cell line were chosen as in vitro cell culture models to examine the possible adverse effects of the carboxylated photoluminescent GQDs. The carboxylated GQDs are desirable for increased aqueous solubility. All cancer cells efficiently took up the carboxylated GQDs. No acute toxicity or morphological changes were noted in either system at the tested exposure levels. A long-term in vivo study revealed that the GQDs mainly accumulated in liver, spleen, lung, kidney, and tumor sites after intravenous injection. To reveal any potential toxic effect of the GQDs on treated mice, serum biochemical analysis and histological evaluation were performed. The toxicity results from serum biochemistry and complete blood count study revealed that the GQDs do not cause appreciable toxicity to the treated animals. Finally, we observed no obvious organ damage or lesions for the GQDs treated mice after 21 days of administration at 5 mg/kg or 10 mg/kg dosages. With adequate studies of toxicity, both in vitro and in vivo, photoluminescent GQDs may be considered for biological application.

Molybdenum disulfide/graphene oxide nanocomposites show favorable lung targeting and enhanced drug loading/tumor-killing efficacy with improved biocompatibility

“…47,48 Nonetheless, emerging evidence also suggests that the nanomaterials themselves could be refined for specific tissue accumulation and thus targeting through either a passive or active mechanism. 49,50 GO materials were uncovered to preferentially localize in the lung upon in vivo administration, [9][10][11][12] pointing out the rationale of using GO for lung targeting. To this end, we synthesized the MoS 2 /GO nanocomposites for the purpose of lung targeting.…”

“…Unlike most of the other nanomaterials, GO tended to localize in the lung via various exposure routes. [9][10][11][12] To be specific, GO was prone to form complex with diverse proteins once in circulation and body fluid, and would mostly likely be trapped in the arteries and capillaries in the lung, which functioned as the first vascular bed for GO sheet localization. 10,13,54 Meanwhile, the microenvironment of pulmonary vasculature, such as endothelial caveolae 55 and distinct membrane proteins on the luminal surface of lung vascular endothelial cells, 56 may also be accountable for targeting of GO sheets.…”

“…Of note, unlike other nanomaterials, graphene oxide (GO) is able to localize in the lung through various exposure routes (for example, intravenous (i.v.) administration), [9][10][11][12] being ascribed to the formation of GO-protein complexes that were readily caught by lung capillary vessels. [13][14][15] GO's selective localization in the lung distinguishes it from other types of nanomaterials (mostly in liver and spleen), 16,17 offering a 'guided missile' to target the lung.…”

From highly graphitic to amorphous carbon dots: A critical review

“…Similarly, addition of gC-dots to the culture medium containing human kidney cells did not induce significant cytotoxicity, 80 while no obvious organ damage was observed for mice treated with carboxylated gC-dots. 81 PEG-passivated gC-dots at high concentrations are relatively toxic to cancer cells, but this effect stems from the passivation agent itself rather than the carbogenic core 82 [ Fig. 13(a) ].…”

Recent Advances in Graphene Quantum Dots as Bioimaging Probes

“…Generally, the approaches can be divided into two groups: top-down and bottom-up methods. In the top-down methods, GQDs are usually synthesized through the cleavage of relatively large bulk precursors, such as graphite [53][54][55], carbon black [56][57][58], coal [59][60][61], metal-organic framework (MOF) [40], 3D graphene [62], graphene oxide (GO) [63][64][65][66][67], carbon nanotubes [68][69][70], carbon fiber [53,[71][72][73] and C 60 [74,75] into small pieces of graphene sheets by chemical oxidation etching [76][77][78][79][80][81], electrochemical exfoliation [65,[82][83][84][85], Li/K intercalation [86,87], hydrothermal/solvothermal treatment [88][89][90][91][92][93][94], microwave irradiation [95...…”