Institute of Materials Research and Engineering, The Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, #08-03, Innovis, 138634, Singapore.
Adv Healthc Mater. 2016 Oct;5(19):2528-2535. doi: 10.1002/adhm.201600312. Epub 2016 Jul 14.
This paper reports a novel synthesis approach of bovine serum albumin (BSA) protein-templated ultrasmall (<2 nm) Ag nanocluster (NC) with strong singlet oxygen generation capacity for photodynamic therapy (PDT). An atomically precise BSA-Ag NC (i.e., 13 Ag atoms per cluster) is successfully synthesized for the first time by using NaOH-dissolved NaBH solution as the controlling reducing agent. The ubiquitous size of BSA-Ag NC results in unique behaviors of its photoexcited states as characterized by the ultrafast laser spectroscopy using time-correlated single photon counting and transient absorption techniques. In particular, triply excited states can be largely present in the excited BSA-Ag NC and readily sensitized molecular oxygen to produce singlet oxygen ( O ) with a high quantum efficiency (≈1.26 using Rose Bengal as a standard). This value is much higher than its Au analogue (i.e., ≈0.07 for BSA-Au NC) and the commonly available photosensitizers. Due to the good cellular uptake and inherent biocompatibility imparted by the surface protein, BSA-Ag NC can be applied as an effective PDT agent in generating O to kill cancer cell as demonstrated in this study.
本文报道了一种新颖的牛血清白蛋白（BSA）蛋白模板超小（<2nm）银纳米团簇（NC）的合成方法，该团簇具有生成单线态氧的能力，可用于光动力疗法（PDT）。首次使用溶解在 NaOH 中的 NaBH4 溶液作为控制还原剂，成功合成了具有原子精度的 BSA-Ag NC（即每个簇 13 个 Ag 原子）。BSA-Ag NC 的普遍大小导致其光激发态具有独特的行为，这可以通过使用时间相关单光子计数和瞬态吸收技术的超快激光光谱学来表征。特别是，三重激发态可以大量存在于激发的 BSA-Ag NC 中，并容易敏化分子氧以产生单线态氧（O），量子效率高（以 Rose Bengal 为标准，约为 1.26）。这一数值远高于其金类似物（即 BSA-Au NC 的约 0.07）和常用的光敏剂。由于表面蛋白赋予的良好细胞摄取和固有生物相容性，BSA-Ag NC 可用作有效的 PDT 试剂，用于生成 O 以杀死癌细胞，本研究对此进行了验证。
