An investigation into the potential for different surface-coated quantum dots to cause oxidative stress and affect macrophage cell signalling in vitro

Abstract

The aim of this study was to investigate the ability of a series of different surface-coated quantum dots (QDs) to cause oxidative stress and affect cell signalling in J774.A1 macrophages. Organic QDs caused a significant (p < 0.001) decrease in glutathione (GSH) levels over 24 h, while COOH and NH₂ (PEG) QDs induced a significant decrease (p < 0.05) in GSH at 6 and 24 h only. J774.A1 cytosolic Ca²⁺ concentration significantly increased (p < 0.01) 30 min after treatment with all QDs. Trolox was, however, able to prevent the COOH and NH₂ (PEG) QD-induced Ca²⁺ signal, but not the organic QD induced effect. All QDs tested were observed to have a relatively low ability to stimulate increased expression of the pro-inflammatory cytokine tumour necrosis factor-alpha (TNF-α). In conclusion, QDs differ in their interactions with macrophages according to their specific surface properties.

Keywords::

• Quantum dots (QDs)
• glutathione (GSH)
• calcium signalling
• pro-inflammatory cytokines
• macrophages

Acknowledgements

The authors would like to acknowledge Dr Helinor Johnston (Edinburgh Napier University) for her constant support, advice and assistance throughout this study. The authors would also like to acknowledge the funding provided by Napier University, The Carnegie Trust and The Colt Foundation that enabled this project to be completed.

Declaration of Interest: The authors would like to report no conflict of interests. The authors are entirely responsible for the content and writing of the manuscript.