aqueous synthesis of genetically engineered polypeptide-capped AgS quantum dots for second near-infrared fluorescence/photoacoustic imaging and photothermal therapy

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Materials for biology and medicine, 2019-04, Vol.7 (15), p.2484-2492
• Main Authors: Zhao, Dong-Hui, Yang, Xiao-Quan, Hou, Xiao-Lin, Xuan, Yang, Song, Xian-Lin, Zhao, Yuan-Di, Chen, Wei, Wang, Qiong, Liu, Bo
• Format: Article
• ISSN: 2050-750X; 2050-7518
• DOI: 10.1039/c8tb03043j

Ag 2 S quantum dots have received extensive attention as theranostic agents for second near-infrared (NIR-II) fluorescence and photoacoustic dual-mode imaging, and photothermal therapy. However, it is still greatly challenging to synthesize Ag 2 S quantum dots using aqueous synthesis. In this study, genetically engineered polypeptide-capped Ag 2 S quantum dots were successfully synthesized. Three cysteines were integrated to the C-terminal and N-terminal of RGDPC 10 A to enhance the stability and brightness of the synthesized Ag 2 S quantum dots. The RGDPC 10 A-capped Ag 2 S quantum dots exhibited excellent stability, outstanding resistance to photobleaching, and a superior quantum yield of up to 3.78% in the NIR-II biological window. The in vitro and in vivo results showed that the RGDPC 10 A-capped Ag 2 S quantum dots possessed typical NIR-II fluorescence, photoacoustic imaging, and photothermal therapeutic effectiveness against tumors. Moreover, the results of toxicity assays suggested that the RGDPC 10 A-capped Ag 2 S quantum dots have negligible long-term toxicity. These findings open up the possibility for synthesizing theranostic agents by using this aqueous method. Polypeptide-engineering capped silver sulfide quantum dots were prepared and used for second near-infrared fluorescence and photoacoustic imaging, and the photothermal therapy of tumors.