Laboratoire Matière et Systèmes Complexes, UMR 7057 , CNRS and University Paris Diderot , 75205 Paris Cedex 13, France.
Sorbonne Université, CNRS, PHysico-chimie des Electrolytes et Nanosystèmes InterfaciauX, PHENIX , F-75005 Paris , France.
ACS Nano. 2018 Jul 24;12(7):6523-6535. doi: 10.1021/acsnano.8b00482. Epub 2018 Jun 26.
Despite their highly efficient plasmonic properties, gold nanoparticles are currently preferred to silver nanoparticles for biomedical applications such as photothermal therapy due to their high chemical stability in the biological environment. To confer protection while preserving their plasmonic properties, we allied the advantages of both materials and produced hybrid nanoparticles made of an anisotropic silver nanoplate core coated with a frame of gold. The efficiency of these hybrid nanoparticles (Ag@AuNPs) in photothermia was compared to monometallic silver nanoplates (AgNPs) or gold nanostars (AuNPs). The structural and functional properties of AuNPs, AgNPs, and Ag@AuNPs were investigated in environments of increasing complexity, in water suspensions, in cells, and in tumors in vivo. While AgNPs showed the greatest heating efficiency in suspension (followed by Ag@AuNPs and AuNPs), this trend was reversed intracellularly within a tissue-mimetic model. In this setup, AgNPs failed to provide consistent photothermal conversion over time, due to structural damage induced by the intracellular environment. Remarkably, the degraded Ag was found to be stored within the iron-storage ferritin protein. By contrast, the Au shell provided the Ag@AuNPs with total Ag biopersistence. As a result, photothermal therapy was successful with Ag@AuNPs in vivo in a mouse tumor model, providing the ultimate proof on Au shell's capability to shield the Ag core from the harsh biological environment and preserve its excellent heating properties.
尽管金纳米粒子具有高效的等离子体特性，但由于其在生物环境中的化学稳定性较高，目前在光热治疗等生物医学应用中，金纳米粒子比银纳米粒子更受欢迎。为了在保持其等离子体特性的同时提供保护，我们结合了这两种材料的优势，制备了由各向异性银纳米板核包裹金框架组成的混合纳米粒子。将这些混合纳米粒子（Ag@AuNPs）的光热性能与单金属银纳米板（AgNPs）或金纳米星（AuNPs）进行了比较。在越来越复杂的环境中，即在水悬浮液中、细胞内以及体内肿瘤中，研究了 AuNPs、AgNPs 和 Ag@AuNPs 的结构和功能特性。虽然 AgNPs 在悬浮液中表现出最大的加热效率（其次是 Ag@AuNPs 和 AuNPs），但在组织模拟模型中，这种趋势在细胞内发生了逆转。在这种设置中，由于细胞内环境引起的结构损伤，AgNPs 无法提供一致的光热转换。值得注意的是，降解的 Ag 被发现储存在铁储存蛋白铁蛋白中。相比之下，Au 壳为 Ag@AuNPs 提供了总 Ag 的生物持久性。因此，Ag@AuNPs 在体内小鼠肿瘤模型中成功进行了光热治疗，为 Au 壳保护 Ag 核免受恶劣生物环境影响并保持其优异加热性能提供了最终证据。
