Redox-responsive biodegradable PEGylated nanographene oxide for efficiently chemo-photothermal therapy: a comparative study with non-biodegradable PEGylated nanographene oxide

J Photochem Photobiol B. 2014 Sep 5;138:191-201. doi: 10.1016/j.jphotobiol.2014.05.023. Epub 2014 Jun 13.


Nanographene oxide (NGO) with a non-sheddable poly(ethylene glycol) (PEG) coating has been used for chemo-photothermal therapy. However, the drug release of PEGylated NGO (NGO-PEG) with an amine bond is adversely affected by the diffusion barrier effect of PEG shells. Here, we developed a simple new method for the preparation of biodegradable PEGylated NGO conjugates (NGO-SS-PEG) with cleavable disulfide bonds for rapid drug release and more efficiently chemo-photothermal therapy. The glutathione (GSH)-induced and photothermal-mediated intracellular release of doxorubicin (DOX) from NGO-SS-PEG was studied in A549 cells using confocal laser scanning microscopy and flow cytometry analysis. In vivo cytotoxicity experiments were performed on chemo-photothermal therapy. Furthermore, we presented a comparative study of intracellular drug release and biological efficacy between NGO-SS-PEG/DOX and NGO-PEG/DOX. The results demonstrated that the rapid drug release from the NGO-SS-PEG conjugates with sheddable PEG was triggered upon the stimulus of high GSH levels inside A549 cells. Interesting, the DOX release mediated by the photothermal effect from the NGO-SS-PEG conjugates was found to be more obvious than that for NGO-PEG. Additionally, NGO-SS-PEG showed a higher efficacy than NGO-PEG for anti-tumor therapy compared with NGO-PEG. Thus, NGO-SS-PEG can improve therapeutic efficacy and is an attractive drug nanocarrier.

Keywords: Chemo-photothermal therapy; Disulfide bonds; Glutathione (GSH); Graphene oxide; Sheddable poly(ethylene glycol).

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell Survival / radiation effects
  • Coated Materials, Biocompatible / chemistry*
  • Disulfides / chemistry
  • Doxorubicin / administration & dosage
  • Doxorubicin / chemistry
  • Doxorubicin / pharmacology
  • Drug Carriers / chemistry*
  • Glutathione / metabolism
  • Graphite / chemistry*
  • Humans
  • Lasers
  • Nanoparticles / chemistry*
  • Neoplasms / drug therapy
  • Neoplasms / radiotherapy
  • Oxidation-Reduction
  • Oxides / chemistry
  • Phototherapy
  • Polyethylene Glycols / chemistry*
  • Temperature


  • Coated Materials, Biocompatible
  • Disulfides
  • Drug Carriers
  • Oxides
  • Polyethylene Glycols
  • Graphite
  • Doxorubicin
  • Glutathione