An effective strategy for the synthesis of biocompatible gold nanoparticles using danshensu antioxidant: prevention of cytotoxicity via attenuation of free radical formation

Abstract

To suppress the cytotoxicity of gold nanoparticles (AuNPs), danshensu, a naturally occurring polyphenol antioxidant isolated from Chinese herb, was used to provide a fundamental protection layer for AuNPs, to alleviate oxidative stress and as a reducing agent to react with chloroauric acid. Besides danshensu, gum arabic was chosen as an auxiliary stabilising agent to improve the stability of AuNPs against aggregation. As expected, the prepared GA–DS–AuNPs (gum arabic–danshensu–gold nanoparticle) was remarkably stable in various buffer solutions. More interestingly, the GA–DS–AuNPs not only did not show any appreciable cytotoxicity, but also could alleviate the oxidative damage induced by AuNPs. Meanwhile, the ROS/RNS scavenging activities of GA–DS–AuNPs was evaluated by electron spin resonance spectroscopy (ESR), potentiometric nitric oxide (NO) sensor and cell confocal imaging. The results suggest that GA–DS–AuNPs might have effectively reduced the AuNPs-induced cytotoxicity and oxidative stress by downregulation of ROS/NOS production. The GA–DS–AuNPs may provide potential opportunities for the application in nanomedicine and nanobiology.

Keywords::

• Nanoparticles
• oxidative stress
• antioxidant
• free radicals
• cell toxicity

Acknowledgements

The work was supported by Knowledge Innovation Program (Grant No. KJCX2-EW-H01) of the Chinese Academy of Sciences, the National Natural Science Foundation of China (No. 90813021, 21005082 & 20875093) and the Seed Funding Programme for Basic Research from the University of Hong Kong. We are very grateful to Dr. Yangping Liu, The Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, for the careful reading and the correction of the manuscript.