title: Synthesis of ultrastable and multifunctional gold nanoclusters with enhanced fluorescence and potential anticancer drug delivery application.
abstract: The problem of stability hinders the practical applications of nanomaterials. In this research, an innovative and simple synthetic method was developed for preparing ultrastable and multifunctional gold nanoclusters (Au NCs). HS-C11-EG6-X is a class of molecules consisting of four components: a mercapto group (-SH), an alkyl chain (C11), a short chain of polyethylene glycols (EG6) and a functional group (X, X=OH, COOH, NH2, GRGD, etc). The present work demonstrated the importance of using HS-C11-EG6-X to prepare Au NCs with excellent properties and the role each component in this molecule played for synthesizing Au NCs. Au NCs with tunable surface functionalities were successfully synthesized and characterized. It was found that Au NC precursors had a fluorescent quantum yield of 0.4%; in contrast, after capping with HS-C11-EG6-X, the quantum yield significantly increased to 1.3-2.6%. The HS-C11-EG6-X capped Au NCs exhibited superior stability under various solution conditions (including extreme pH, high salt concentration, phosphate buffered saline and cell medium) for at least 6 months, even after conjugation with anticancer drug doxorubicin. Besides, we have also demonstrated that other commonly employed thiol-containing ligands failed to prepare stable fluorescent Au NCs. Moreover, the Au NCs showed negligible toxicity to A549 lung cancer cells up to 100 μM, and the application of the ultrastable Au NCs for anticancer drug delivery has also been demonstrated.
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China. Electronic address: wufg@seu.edu.cn.
authors.forename: Fu-Gen
authors.initials: FG
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China; School of Medicine, Southeast University, Nanjing 210009, China.
authors.forename: Peidang
authors.initials: P
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Hong-Yin
authors.initials: HY
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Gu
authors.affiliation: Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109, United States. Electronic address: zhanc@umich.edu.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004317:Doxorubicin / Q000737:chemistry / Q000494:pharmacology*; D004337:Drug Carriers; D004339:Drug Compounding; D004355:Drug Stability; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology; D005453:Fluorescence; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011092:Polyethylene Glycols / Q000737:chemistry; D011789:Quantum Theory; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D013438:Sulfhydryl Compounds; D011092:Polyethylene Glycols; D006046:Gold; D004317:Doxorubicin
keywords: Anticancer; Gold nanoclusters; Short-chain PEGs; Ultrastable