The preparation and characterization of gold-conjugated polyphenol nanoparticles as a novel delivery system

Dar-Shih Hsieh^1,2, Hsiu-Chin Lu⁵, Cheng-Cheung Chen^1,3, Chang-Jer Wu^1,*, Ming-Kung Yeh<sup>4,*

1</sup>Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan; ²Division of Urology, ³Department of Pathology, Tri-Service General Hospital, ⁴Institute of Preventive Medicine, National Defence Medical Center, Taipei, Taiwan; ⁵Department of Laboratory Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan

*These authors contributed equally to this work

Abstract: Nanogold particles are commonly used in nanomedicine. We generated physical nanogold (pNG) conjugated with different ratios of epigallocatechin-3-gallate (EGCG) and evaluated its physicochemical properties, antioxidant activity, and cytotoxicity in vitro as well as anticancer activity in vivo. Results showed that the EGCG-pNG conjugates were successfully prepared at ratios between 23:1 and 23:5, with the percentage of EGCG content increasing with the EGCG:pNG ratio from 23:1 (2.0% ± 0.02%) to 23:5 (28% ± 0.3%). EGCG-pNG particles at ratios of 23:1 and 23:5 demonstrated significantly decreased size from 500 to 20 nm and decreasing zeta potentials of 21 mV to –22 mV, respectively. At a ratio of 23:2.5, the EGCG-pNG particles (27% EGCG, 50 nm in size, zeta potential of –8 mV) showed longer EGCG activity half-life (110 days vs 5 hours), controlled release (2 hours vs 30 minutes), and higher antioxidant activity (four times), as well as inhibition of tumor cell growth, than controls. The present study indicated that EGCG-pNG possesses promising therapeutic potential, based on its strong free-radical scavenging and anticancer activities.

Keywords: EGCG, nanoparticles, antioxidant, antitumor activity, nanogold

This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.