Sotiriou Georgios A, Hirt Ann M, Lozach Pierre-Yves, Teleki Alexandra, Krumeich Frank, Pratsinis Sotiris E
Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland.
Chem Mater. 2011 Apr 12;23(7):1985-1992. doi: 10.1021/cm200399t.
Hybrid plasmonic-magnetic nanoparticles possess properties that are attractive in bioimaging, targeted drug delivery, diagnosis and therapy. The stability and toxicity, however, of such nanoparticles challenge their safe use today. Here, biocompatible, SiO-coated, Janus-like Ag/FeO nanoparticles are prepared by one-step, scalable flame aerosol technology. A nanothin SiO shell around these multifunctional nanoparticles leaves intact their morphology, magnetic and plasmonic properties but minimizes the release of toxic Ag ions from the nanosilver surface and its direct contact with live cells. Furthermore, this silica shell hinders flocculation and allows for easy dispersion of such nanoparticles in aqueous and biological buffer (PBS) solutions without any extra functionalization step. As a result, these hybrid particles exhibited no cytotoxicity during bioimaging and remained stable in suspension with no signs of agglomeration and sedimentation or settling. Their performance as biomarkers was explored by selectively binding them with live tagged Raji and HeLa cells enabling their detection under dark-filed illumination. Therefore, these SiO-coated Ag/FeO nanoparticles do not exhibit the limiting physical properties of each individual component but retain their desired functionalities facilitating thus, the safe use of such hybrid nanoparticles in bio-applications.
混合等离子体-磁性纳米颗粒具有在生物成像、靶向药物递送、诊断和治疗方面具有吸引力的特性。然而，这类纳米颗粒的稳定性和毒性对它们如今的安全使用构成了挑战。在此，通过一步可扩展的火焰气溶胶技术制备了具有生物相容性的、包覆SiO的类Janus结构Ag/FeO纳米颗粒。这些多功能纳米颗粒周围的纳米级SiO薄壳使其形态、磁性和等离子体特性保持完整，但将纳米银表面有毒Ag离子的释放降至最低，并使其与活细胞的直接接触减到最少。此外，这种二氧化硅壳阻碍絮凝，并使得此类纳米颗粒无需任何额外功能化步骤就能轻松分散于水性和生物缓冲（PBS）溶液中。结果，这些混合颗粒在生物成像过程中未表现出细胞毒性，并且在悬浮液中保持稳定，没有团聚、沉淀或沉降的迹象。通过将它们与活的标记Raji和HeLa细胞选择性结合，在暗场照明下实现对其检测，从而探索了它们作为生物标志物的性能。因此，这些包覆SiO的Ag/FeO纳米颗粒并未表现出各单个组分的局限性物理特性，而是保留了其所需功能，从而促进了此类混合纳米颗粒在生物应用中的安全使用。
