Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, P. R. China.
Small. 2017 Dec;13(48). doi: 10.1002/smll.201703007. Epub 2017 Nov 2.
The low reactive oxygen species production capability and the shallow tissue penetration of excited light (UV) are still two barriers in photodynamic therapy (PDT). Here, Au cluster anchored black anatase TiO nanotubes (abbreviated as Au /B-TiO NTs) are synthesized by gaseous reduction of anatase TiO NTs and subsequent deposition of noble metal. The Au /B-TiO NTs with thickness of about 2 nm exhibit excellent PDT performance. The reduction process increased the density of Ti on the surface of TiO , which effectively depresses the recombination of electron and hole. Furthermore, after modification of Au nanoclusters, the PDT efficiency is further enhanced owing to the changed electrical distribution in the composite, which forms a shallow potential well on the metal-TiO interface to further hamper the recombination of electron and hole. Especially, the reduction of anatase TiO can expend the light response range (UV) of TiO to the visible and even near infrared (NIR) light region with high tissue penetration depth. When excited by NIR light, the nanoplatform shows markedly improved therapeutic efficacy attributed to the photocatalytic synergistic effect, and promotes separation or restrained recombination of electron and hole, which is verified by experimental results in vitro and in vivo.
活性氧产生能力低和受激光（UV）的浅层组织穿透仍然是光动力疗法（PDT）的两个障碍。在这里，通过锐钛矿 TiO 纳米管的气相还原和随后的贵金属沉积合成了 Au 团簇锚定的黑锐钛矿 TiO 纳米管（简称 Au/B-TiO NTs）。厚度约为 2nm 的 Au/B-TiO NTs 表现出优异的 PDT 性能。还原过程增加了 TiO 表面上 Ti 的密度，这有效地抑制了电子和空穴的复合。此外，修饰 Au 纳米团簇后，由于复合材料中电分布的改变，进一步提高了 PDT 效率，在金属-TiO 界面上形成了浅势阱，进一步阻碍了电子和空穴的复合。特别是，锐钛矿 TiO 的还原可以将 TiO 的光响应范围（UV）扩展到具有高组织穿透深度的可见光甚至近红外（NIR）光区。当用近红外光激发时，由于光催化协同效应，纳米平台显示出明显改善的治疗效果，并促进了电子和空穴的分离或抑制复合，这通过体外和体内的实验结果得到了验证。
