Abstract: In order to enhance the effect of photosensitizer photodynamic therapy on leukemia, the photocatalytic inactivation effects of composite nanoparticles FA-CS@Fe-TiO2 on HL60 cells were studied. The composite nanoparticles FA-CS@Fe-TiO2 were formed by the modification of tumor-targeting molecule folic acid (FA), plus Fe-TiO2 was wrapped by chitosan nanoparticles (CS-NP). FA-CS@Fe-TiO2 nanoparticles were prepared by sol-gel method, two-step method, and surface modification method, and analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier infrared spectroscopy. The CCK-8 method and active oxygen content analysis method were used to analyze the mechanism of FA-CS@Fe-TiO2 photocatalytic inactivation of HL60 cells. Cell test results showed that under non-light conditions, chitosan (CS) itself had no obvious inhibitory effect on cell growth, and it had a certain promotion effect on cells at low mass concentrations of 5µg/mL. Compared to Fe-TiO2 and FA-CS@Fe-TiO2 nanomaterials, the toxicity of CS@Fe-TiO2 was significantly reduced, and even at a high quality concentration of 160µg/mL, the relative survival of HL60 with CS@Fe-TiO2 (3:2) can still be as high as 85%, which indicates that the coating of chitosan can improve the biocompatibility of the composite nanoparticles. Photodynamic therapy (PDT) tests have shown that folic acid modification can significantly increase the uptake of composite nanoparticles by HL60 cells and enhance its inactivation efficiency to HL60 cells. The highest PDT inactivation effect of FA-CS@Fe-TiO2 nanoparticles was 78.75%. It provides a reference for the clinical application of photodynamic therapy in the treatment of leukemia tumor cells.
Key words: FA-CS@Fe-TiO2; tumor molecular targeting; biocompatibility; photodynamic therapy; HL60 cells