Silver, gold, and alloyed silver–gold nanoparticles: characterization and comparative cell-biologic action

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 14; no. 10; pp. 1 - 13
• Main Authors: Mahl, Dirk, Diendorf, Jörg, Ristig, Simon, Greulich, Christina, Li, Zi-An, Farle, Michael, Köller, Manfred, Epple, Matthias
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.10.2012; Springer Nature B.V
• Subjects: Activation; Characterization and Evaluation of Materials; Chemistry and Materials Science; Culture media; Gold; Inorganic Chemistry; Lasers; Materials Science; Nanoparticles; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Reduction; Research Paper; Sedimentation; Silver; Stem cells; Synthesis; Viability; Nanoparticles; Silver; Gold; Cytotoxicity; Health effects; Silver–gold-alloys
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-012-1153-5

Silver, gold, and silver–gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly( N -vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15–25 nm), gold (5–6 nm), and silver–gold (50:50; 10–12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver–gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver–gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver–gold nanoparticles in the concentration range of 5–20 μg mL −1 induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.