Vankayala Raviraj, Kuo Chien-Lin, Sagadevan Arunachalam, Chen Po-Hung, Chiang Chi-Shiun, Hwang Kuo Chu
Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013.
J Mater Chem B. 2013 Sep 21;1(35):4379-4387. doi: 10.1039/c3tb20806k. Epub 2013 Jul 26.
Singlet oxygen is a very important reactive oxygen species (ROS) involved in peroxidation of olefins and polymers, as well as in clinical photodynamic therapy treatments of tumors. Previously, it was reported that singlet oxygen can be formed via sensitization by spherical metal nanoparticles upon photo-excitation of the surface plasmon resonance (SPR) bands. In this paper, we report that sensitization and formation of singlet O is strongly dependent on the morphologies of gold and silver nanostructures. For example, singlet O can be generated via photo-irradiation and sensitization of silver decahedrons and silver triangular nanoplates, but not by silver nanocubes and gold decahedrons. The sensitization patterns of silver and gold nanoparticles are the reverse of each other. In the case of gold nanorods, singlet O can be generated via photo-excitation at the longitudinal SPR band, but not by excitation at the transverse SPR band. The controlling factors for such a morphology dependent singlet O sensitization will be discussed. Furthermore, we also demonstrate in vitro morphology dependent sensitization behaviour of silver nanoparticles in the photodynamic cancer treatment. Our results indicate that metal nanoparticles with certain morphologies are potentially very promising dual functional nanomaterials with capabilities of simultaneously serving as near infrared (NIR) activatable photodynamic therapy and photothermal therapy reagents for cancer treatments.
单线态氧是一种非常重要的活性氧（ROS），参与烯烃和聚合物的过氧化反应，以及肿瘤的临床光动力治疗。此前有报道称，在表面等离子体共振（SPR）带的光激发下，单线态氧可通过球形金属纳米颗粒的敏化作用形成。在本文中，我们报道单线态氧的敏化和形成强烈依赖于金和银纳米结构的形态。例如，通过光照射和银十面体及银三角形纳米板的敏化作用可以产生单线态氧，但银纳米立方体和金十面体则不能。银和金纳米颗粒的敏化模式彼此相反。对于金纳米棒，通过纵向SPR带的光激发可以产生单线态氧，但通过横向SPR带的激发则不能。将讨论这种形态依赖性单线态氧敏化的控制因素。此外，我们还展示了银纳米颗粒在光动力癌症治疗中的体外形态依赖性敏化行为。我们的结果表明，具有特定形态的金属纳米颗粒可能是非常有前途的双功能纳米材料，能够同时作为用于癌症治疗的近红外（NIR）可激活光动力治疗和光热治疗试剂。
