Use of Ag-Au-ICG to increase fluorescence image of human hepatocellular carcinoma cell lines

Abstract

Indocyanine green (ICG) is effective for a variety of applications including liver tumour imaging and operates in the near-infrared window. Agents for near-infrared imaging are, however, still in clinical development. The present study aimed to prepare and investigate fluorescence emission properties of ICG in combination with Ag-Au in order to enhance their specific interactions with human hepatocellular carcinoma cell lines (HepG-2). The Ag-Au-ICG complex was prepared via physical adsorption, and hence evaluated for fluorescence spectra using a spectrophotometer. Ag-Au-ICG at an optimised dosage (Ag-Au:ICG = 0.0147:1 molar ratio) in Intralipid medium was added to HepG-2 to observe the maximum fluorescence signal intensity, which further enhanced HepG-2 contrast fluorescence. Ag-Au-ICG served as a fluorescence enhancer bound onto the liposome membrane, whilst free Ag, Au, and pure ICG induced low levels of cytotoxicity in HepG-2 and a normal human cell line. Thus, our findings provided new insights for the liver cancer imaging.

Highlights

• Concentration-dependent fluorescence peaking in the near-infrared window revealed ICG aggregation in Ag-Au molecules.

• Ag-Au-ICG fluorescence intensity depended strongly on the environmental media.

• Human hepatocellular carcinoma cell lines treated with Ag-Au-ICG in Intralipid enhanced the contrast of fluorescence microscopy images by decreasing the level of scattering in the cell lines with the contrast values being approximately five times those observed in pure ICG in Intralipid.

Keywords:

• Fluorescence
• indocyanine green
• imaging
• liver cancer
• nanoparticles

Acknowledgments

The authors thank the Scientific Instrument Center, School of Science, King Mongkut’s Institute of Technology Ladkrabang, Thailand for providing the cancer cell lines.

Ethics approval and consent to participate

Not applicable.

Author contributions

Pattarapol Sittisart participated in the research design, data collection, data analysis, and wrote the manuscript. Kitsakorn Locharoenrat devised the research design and performed the data analysis, research summary and recommendation, as well as wrote the manuscript. Both authors read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Funding

The research on “Use of Ag-Au-ICG to increase fluorescence image of human hepatocellular carcinoma cell lines” by King Mongkut’s Institute of Technology Ladkrabang (KMITL) has received funding support from the NSRF [FRB660065/0258-RE-KRIS/FF66/70].