Biosynthesis of flower-shaped Au nanoclusters with EGCG and their application for drug delivery

Shichao Wu,Ting Wu,Mingyuan Zou,Fanghong Luo,Peilan Xu,Xiangrui Yang,Jianghua Yan

doi:10.1186/s12951-018-0417-3

Abstract

BackgroundIn the last decade, the biosynthesis of metal nanoparticles using organisms have received more and more considerations. However, the complex composition of organisms adds up to a great barrier for the characterization of biomolecules involved in the synthesis process and their biological mechanisms.ResultsIn this research, we biosynthesized a kind of flower-shaped Au nanoclusters (Au NCs) using one definite component—epigallocatechin gallate (EGCG), which was the main biomolecules of green tea polyphenols. Possessing good stability for 6 weeks and a size of 50 nm, the Au NCs might be a successful candidate for drug delivery. Hence, both methotrexate (MTX) and doxorubicin (DOX) were conjugated to the Au NCs through a bridge of cysteine (Cys). The introduction of MTX provided good targeting property for the Au NCs, and the conjugation of DOX provided good synergistic effect. Then, a novel kind of dual-drug loaded, tumor-targeted and highly efficient drug delivery system (Au-Cys-MTX/DOX NCs) for combination therapy was successfully prepared. The TEM of HeLa cells incubated with Au-Cys-MTX/DOX NCs indicated that the Au-Cys-MTX/DOX NCs could indeed enter and kill cancer cells. The Au-Cys-MTX/DOX NCs also possessed good targeting effect to the FA-receptors-overpressed cancer cells both in vitro and in vivo. Importantly, the Au-Cys-MTX/DOX NCs resulted in an excellent anticancer activity in vivo with negligible side effects.ConclusionsThese results suggest that the biosynthesized Au-Cys-MTX/DOX NCs could be a potential carrier with highly efficient anticancer properties for tumor-targeted drug delivery.

Highlights

In the last decade, the biosynthesis of metal nanoparticles using organisms have received more and more considerations
Since the NPs of 50 nm were proved to be internalized much more rapidly and efficiently by cancer cells than those of other sizes, we investigated the application of the flower-shaped Au nanoclusters (Au NCs) as drug deliver carriers
Synthesis of flower‐shaped Au nanoclusters (Au NCs) Different from other biosynthesis methods, a key feature of the experiments is the biosynthesis of flower-shaped Au nanoclusters (Au NCs) with only one component— epigallocatechin gallate (EGCG)

Summary

Results

We biosynthesized a kind of flower-shaped Au nanoclusters (Au NCs) using one definite component—epigallocatechin gallate (EGCG), which was the main biomolecules of green tea polyphenols. Possessing good stability for 6 weeks and a size of 50 nm, the Au NCs might be a successful candidate for drug delivery. Both methotrexate (MTX) and doxorubicin (DOX) were conjugated to the Au NCs through a bridge of cysteine (Cys). The introduction of MTX provided good targeting property for the Au NCs, and the conjugation of DOX provided good synergistic effect. A novel kind of dual-drug loaded, tumor-targeted and highly efficient drug delivery system (Au-Cys-MTX/DOX NCs) for combination therapy was successfully prepared. The Au-Cys-MTX/DOX NCs possessed good targeting effect to the FA-receptors-overpressed cancer cells both in vitro and in vivo. The Au-Cys-MTX/DOX NCs resulted in an excellent anticancer activity in vivo with negligible side effects

Background

Materials and methods

Results and discussion

Conclusion