Improving cytotoxicity against cancer cells by chemo-photodynamic combined modalities using silver-graphene quantum dots nanocomposites

Abstract

The combination of chemotherapy and photodynamic therapy has emerged as a promising strategy for cancer therapy due to its synergistic effects. In this work, PEGylated silver nanoparticles decorated with graphene quantum dots (Ag-GQDs) were tested as a platform to deliver a chemotherapy drug and a photosensitizer, simultaneously, in chemo-photodynamic therapy against HeLa and DU145 cancer cells in vitro. Ag-GQDs have displayed high efficiency in delivering doxorubicin as a model chemotherapy drug to both cancer cells. The Ag-GQDs exhibited a strong antitumor activity by inducing apoptosis in cancer cells without affecting the viability of normal cells. Moreover, the Ag-GQDs exhibited a cytotoxic effect due to the generation of the reactive singlet oxygen upon 425 nm irradiation, indicating their applicability in photodynamic therapy. In comparison with chemo or photodynamic treatment alone, the combined treatment of Ag-GQDs conjugated with doxorubicin under irradiation with a 425 nm lamp significantly increased the death in DU145 and HeLa. This study suggests Ag-GQDs as a multifunctional and efficient therapeutic system for chemo-photodynamic modalities in cancer therapy.

Keywords:

• multifunctional nanoparticles
• silver nanoparticles
• cancer therapy
• drug delivery
• photodynamic therapy
• nanocomposites

Acknowledgments

This research was carried out under the auspices of the Institute for Functional Nanomaterials (NSF Cooperative Agreement 1002410), PR NASA EPSCoR (NASA Cooperative Agreement [NNX15AK43A]), PR NASA Space Grant Consortium at University of Puerto Rico-Bayamon Campus (PRNSGC – UPRB), U54 UPR-MD Anderson Cancer Center Partnership Program (National Cancer Institute through the U54 CA096297/CA096300), and UPR GK-12 Fellowship Program (NSF Grant No. 0841338). We want to acknowledge Mr Oscar Resto from the University of Puerto Rico – Rio Piedras Campus for taking HR-TEM images, Dr Carlos I Gonzalez and Dr Jose A Gonzalez-Feliciano for providing HeLa and DU145 cells, Dr Anthony V Washington for providing access to the fluorescence microscope and Dr Elizabeth Hunsperger from CDC for providing Vero cells.

Author contributions

All authors contributed toward data analysis, drafting and revising the paper and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.