Effect of photothermal and photodynamic therapy with cobalt ferrite superparamagnetic nanoparticles loaded with ICG and PpIX on cancer stem cells in MDA-MB-231 and A375 cell lines.

BACKGROUND

Cancer cells are resistant to treatments such as chemotherapy and radiotherapy due to their characteristics such as self-renewal, high proliferation and other resistance mechanisms. To overcome this resistance, we combined a light-based treatment with nanoparticles to get advantage of both PDT and PTT in order to increase efficiency and beater outcome.

METHODS AND MATERIAL: After synthesis and characterization of CoFe2O4@citric@PEG@ICG@ PpIX NPs, their dark cytotoxicity concentration was determined with MTT assay. Then light-base treatments were performed by two different light source for MDA-MB-231 and A375 cell lines. After treatment, the results were evaluated 48 h and 24 h after treatment by MTT assay and flow cytometry. Among CSCs defined markers, CD44, CD24 and CD133 are the most widely-used markers in CSC research and are also therapeutic targets in cancers. So we used proper antibodies to detect CSCs. Then indexes like ED50, synergism defined to evaluated the treatment.

RESULTS

ROS production and temperature increase have a direct relationship with exposure time. In both cell lines, the death rate in combinational treatment (PDT/PTT) is higher than single treatment and the amount of cells with CD44+CD24- and CD133+CD44+ markers has decreased. According to the synergism index, conjugated NPs show a high efficiency in use in light-based treatments. This index was higher in cell line MDA-MB-231 than A375. And the ED50 is proof of the high sensitivity of A375 cell line compared to MDA-MB-231 in PDT and PTT.

CONCLUSION

Conjugated NPs along with combined photothermal and photodynamic therapies may play an important role in eradication CSCs.