The Cell Labeling And Cytotoxicity Detection Of CuInS₂-ZnS-AFP Fluorescence Probe In Liver Cancer Cells

Objective: To evaluate the potential of applying water-soluble Cu In S2-Zn S-AFP fluorescence probe into investigating liver cancer by detecting its cytotoxicity and biocompatibility in a liver cancer cell line(Hep-G2).Methods: Immunohistochemistry was used to investigate the expression of AFP.Cu In S2-Zn S core/shell quantum dots(QDs) were transformed into a nanoprobe with biological target property through conjugating with anti-AFP antibody. Optical experiments were used to measure the absorption spectrum(UV-Vis) and fluorescence spectrum(PL) of Cu In S2-Zn S-AFP probe. Cell inhibition rates of Cu In S2-Zn S-AFP probe were explored by MTT assays and QDs-produced cell apoptosis was detected by flow cytometry(FCM), as well as cell morphology was observed by co-culturing test.Cell labeling and imaging experiments was conducted to explore the combining and targeting capacity and biocompatibility of QDs probe.Results: Immunohistochemistry presented abundant AFP expressed in Hep-G2 cytoplasm. Optical experiments showed that Cu In S2-Zn S-AFP probe had suitable Stokes’ Shift. MTT assays indicated that cytotoxicity of Cu In S2-Zn S-AFP probe was low. In Cu In S2-Zn S-AFP group no statistical significance was analyzed in low concentrations(<20%, P>0.05), but was presented in intermediate and high concentrations(>20%, P<0.05) that inhibition rate was positively correlated with incubation time and probe concentration. In Cd Te-Zn S-AFP group, inhibition rate was positively correlated with co-culturing time in terms of time-dependent and dosedependent effect(P<0.05). Flow cytometry presented a similar cytotoxicity level in the aspect of cell apoptosis. No cell morphology changes were observed in the co-culturing experiments. Intensive yellow fluorescence was observed in Hep-G2 cytoplasm in cell labeling and imaging experiment of Cu In S2-Zn S-AFP probe.Conclusions: The expression of AFP in human liver cancer cells Hep-G2 was demonstrated in this study. Anti-AFP antibody conjugated Cu In S2-Zn S QDs could effectively enter into cells without optical property decaying which intensive yellow fluorescence was observed in cytoplasm. A low cytotoxicity of this water-soluble ternary QDs were presented in MTT assays and FCM, and nice compatibility was observed in the co-culturing experiment. Comprehensively, this ternary QDs probe has low cytotoxicity and nice biocompatibility, which can be used to label and image cells in vitro.