Search

Ag2S 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 Ag2S quantum dots using aqueous synthesis. In this study, genetically engineered polypeptide-capped Ag2S quantum dots were successfully synthesized. Three cysteines were integrated to the C-terminal and N-terminal of RGDPC10A to enhance the stability and brightness of the synthesized Ag2S quantum dots. The RGDPC10A-capped Ag2S 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 RGDPC10A-capped Ag2S quantum dots possessed typical NIR-II fluorescence, photoacoustic imaging, and photothermal therapeutic effectiveness against tumors. Moreover, the results of toxicity assays suggested that the RGDPC10A-capped Ag2S quantum dots have negligible long-term toxicity. These findings open up the possibility for synthesizing theranostic agents by using this aqueous method. [ABSTRACT FROM AUTHOR]

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.

In this study, an oil-soluble Ag 2 S quantum dot (QD) was synthesized through thermal decomposition using the single-source precursor method, and Pluronic F127 (PF127), a triblock copolymer functionalized with folic acid (FA), was deposited on the surface of the QD, then a water-soluble PF127-FA@Ag 2 S nanoprobe with targeting ability was fabricated. The as-prepared PF127-FA@Ag 2 S exhibited spheroidal morphology and high dispersibility, with average diameters of 115 ± 20.7 nm (as observed by transmission electron microscopy). No obvious toxicity of the PF127-FA@Ag 2 S nanoprobe was found in standard 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and colony-formation assay, indicating good biocompatibility and safety. The resulting PF127-FA@Ag 2 S exhibited excellent stability between 4 °C-40 °C. Additionally, the capacity of the tumor cell-targeting high contrast enhanced photoacoustic imaging of PF127-FA@Ag 2 S was verified in comparison with A547 and HeLa cells. In other words, the excellent properties of PF127-FA@Ag 2 S show great potential in further research for targeting and photoacoustic imaging.