title: A new photothermal therapeutic agent: core-free nanostructured Au x Ag1-x dendrites.
abstract: A new class of Au(x)Ag(1-x) nanostructures with dendrite morphology and a hollow interior were synthesized by using a replacement reaction between Ag dendrites and an aqueous solution of HAuCl(4). The Ag nanostructured dendrites were generated by the reaction of AgNO(3) with ascorbic acid in a methanol/water system. The dendrites resemble a coral shape and are built up of many stems with an asymmetric arrangement. Each stem is approximately 400 nm in length and 65 nm in diameter. The bimetallic composition of Au(x)Ag(1-x) can be tuned by the addition of different amounts of HAuCl(4) to the Ag dendritic solution. The hollowing process resulted in tubular structures with a wall thickness of 10.5 nm in Au(0.3)Ag(0.7) dendrites. The UV/Vis spectra indicate that the strongest NIR absorption among the resulting hollow Au(x)Ag(1-x) dendrites was in Au(0.3)Ag(0.7). The MTT assay was conducted to evaluate the cytotoxicity of Ag dendrites, hollow Au(0.06)Ag(0.94) and Au(0.3)Ag(0.7) dendrites, and Au nanorods. It was found that hollow Au(0.06)Ag(0.94) and Au(0.3)Ag(0.7) dendrites exhibited good biocompatibility, while both Ag dendrites and Au nanorods showed dose-dependent toxicity. Because of absorption in the NIR region, hollow Au(0.3)Ag(0.7) dendrites were used as photothermal absorbers for destroying A549 lung cancer cells. Their photothermal performance was compared to that of Au nanorod photothermal therapeutic agents. As a result, the particle concentration and laser power required for efficient cancer cell damage were significantly reduced for hollow Au(0.3)Ag(0.7) dendrites relative to those used for Au nanorods. The hollow Au(0.3)Ag(0.7) nanostructured dendrites show potential in photothermolysis for killing cancer cells.
authors.affiliation: Department of Chemistry, National Cheng Kung University, No 1. University Road, Tainan City, Taiwan.
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Hu
authors.forename: Chih-Chia
authors.initials: CC
authors.lastname: Huang
authors.forename: Jih-Ru
authors.initials: JR
authors.lastname: Hwu
authors.forename: Wu-Chou
authors.initials: WC
authors.lastname: Su
authors.forename: Dar-Bin
authors.initials: DB
authors.lastname: Shieh
authors.forename: Chen-Sheng
authors.initials: CS
authors.lastname: Yeh
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology / Q000528:radiation effects; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D050091:Dendrimers / Q000737:chemistry* / Q000494:pharmacology / Q000528:radiation effects; D004354:Drug Screening Assays, Antitumor; D006046:Gold / Q000737:chemistry* / Q000494:pharmacology / Q000528:radiation effects; D006801:Humans; D007834:Lasers; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D010316:Particle Size; D010777:Photochemistry; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology / Q000528:radiation effects; D013696:Temperature
chemical_list: D000970:Antineoplastic Agents; D050091:Dendrimers; D012834:Silver; D006046:Gold