SYNTHESIS AND PHYSICAL-CHEMICAL CHARACTERIZATION OF GOLD NANOPARTICLES USING EPIGALOCATEACHINE-3-GALATE (EGCG)
Name: GISELE PEREIRA DINIZ SCHUENCK
Publication date: 19/04/2018
Advisor:
Name |
Role |
|---|---|
| MARCO CESAR CUNEGUNDES GUIMARÃES | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| BRENO VALENTIM NOGUEIRA | Internal Examiner * |
| MARCO CESAR CUNEGUNDES GUIMARÃES | Advisor * |
Summary: Gold nanoparticles (AuNPs) are likely to provide an attractive platform for combining a variety of biophysicochemical properties into a unified nanodevice with great therapeutic potential. In this study we investigated the capacity of a natural polyphenol, epigallocatechin-3-gallate (EGCG) to allow chemical reduction of gold salts to AuNPs and stabilization in a single-step green process. The gold nanoparticles were synthesized by oxy-reduction, based on a Fractional Factorial Design (screening) and then a Central Composite Design (optimization) in order to determine the optimal points for the synthesis. The characterization of AuNPs was performed with UV-Vis, Infrared, Raman, Zeta Potential, ICP-MS and Transmission Electron Microscopy analyzes. In addition, the cytotoxic activity in the mouse macrophages model was examined. The absorbance peak occurred at 533 nm and the mean nanoparticle diameter was 14,54 nm. Nanoformulation showed good in vitro stability over more than 6 months and its zeta potential was -34,89 mV, suggesting that EGCG coating prevents aggregation. ICP-MS analysis showed that the reduced gold concentration with the green synthesis was 29,05 mg/L. The data obtained by Infrared and Raman spectroscopy confirmed the presence of EGCG in gold nanoparticles. The colloid did not present a cytotoxic effect for the model tested. The inhibitory concentration at the 50% cell survival (IC 50) effect for AuNPs-EGCG was 156,9 mg/L. No chemicals, other than gold salts, were used in this green biogenic nanotechnology process, opening up excellent opportunities for biomedical applications.
