The Fe-doped TiO2nanocomposites synthesized by a deposition-precipitation method were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and UV-vis adsorption spectra and then were taken as a new “photosensitizer” for photodynamic therapy (PDT). The photocatalytic inactivation of Fe-doped TiO2on Leukemic HL60 cells was investigated using PDT reaction chamber based on LED light source, and the viability of HL60 cells was examined by Cell Counting Kit-8 (CCK-8) assay. The experimental results showed that the growth of leukemic HL60 cells was significantly inhibited by adding TiO2nanoparticles, and the inactivation efficiency could be effectively enhanced by the surface modification of TiO2nanoparticles with Fe doping. Furthermore, the optimized conditions were achieved at 5 wt% Fe/TiO2at a final concentration of 200 μg/mL, in which up to 82.5% PDT efficiency for the HL60 cells can be obtained under the irradiation of 403 nm light (the power density is 5 mW/cm2) within 60 minutes.

The Fe-N co-doped TiO2nanocomposites were synthesized by a sol-gel method and characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), ultraviolet-visible absorption spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). Then the photocatalytic inactivation of Fe-N-doped TiO2on leukemia tumors was investigated by using Cell Counting Kit-8 (CCK-8) assay. Additionally, the ultrastructural morphology and apoptotic percentage of treated cells were also studied. The experimental results showed that the growth of leukemic HL60 cells was significantly inhibited in groups treated with TiO2nanoparticles and the photocatalytic activity of Fe-N-TiO2was significantly higher than that of Fe-TiO2and N-TiO2, indicating that the photocatalytic efficiency could be effectively enhanced by the modification of Fe-N. Furthermore, when 2 wt% Fe-N-TiO2nanocomposites at a final concentration of 200 μg/mL were used, the inactivation efficiency of 78.5% was achieved after 30-minute light therapy.

The leukaemia cells HL60, incubated in 10 mM/ml ALA (5-aminolevulinic) for 4 hours, were carried an experimental research with fluorescent probes in photodynamic therapy (PDT) based on ALA by using PDT reaction room (The average fluence rate of the 412 nm source was 5 mW/cm²). Cells viability were determined using a Cell Counting Kit-8 (CCK-8) assay, and PpIX Photobleaching of subcellular distributed sites of HL60 cells in vitro were investigated by fluorescence spectra acquired during treatment. The results showed that the fluorescence intensity of mitochondria, lysosomes, endoplasmic reticulum had decreased by 81.5%, 52.3% and 21.0%, respectively, compared with their initial values after a 45-minute light treatment. The rate of PpIX photobleaching in mitochondria was significantly higher than others. Addi-tionally, the change of the activity of HL60 cells was basically characterized by the change fluorescence intensity in mitochondria, which suggest that mitochondria is one of main therapeutic targets of photodynamic therapy

CdS quantum-dots-(QDs-)dopedTiO2nanocomposites were successfully synthesized using the sol-gel technique and characterized by SEM, TEM, XRD, EDS, UV-Vis, and FS. They were then used as a new “photosensitizer” based on photodynamic therapy (PDT) for cancer-cell treatment. The photocatalytic activities of CdS-TiO2on leukemia tumors were investigated by using Cell Counting Kit-8 (CCK-8) assay. The ultrastructural morphology of treated cells was also studied by AFM. The experimental results indicated that an obvious inhibition of tumor growth would be observed in groups treated with CdS-TiO2nanocomposites, and the PDT efficiency in the presence of CdS-dopedTiO2was significantly higher than that ofTiO2, revealing that the photocatalytic activities ofTiO2could be effectively enhanced by the modification of CdS QDs. Additionally, CdS-TiO2can exhibit a very high photodynamic efficiency of 80.5% at a final concentration of 200μg/mL under visible-light irradiation. CdS-TiO2nanocomposites in this case were regarded as a promising application for cancer-cell treatment.

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