Facile internalization of paclitaxel on titania nanoparticles in human lung carcinoma cells after adsorption of serum proteins

The enhanced damage of human carcinoma cells was achieved using paclitaxel (PTX)-assembled TiO2 nanoparticles (NPs). The crystalline structures and light absorption properties of the TiO2 NPs were examined by X-ray diffraction patterns and ultraviolet–visible absorption spectroscopic tools. The fabrication of PTX and serum proteins on TiO2 NPs via self-assembly was checked by diffuse reflectance infrared Fourier transform spectroscopy and dynamic light scattering measurements. The PTX-coated TiO2 NPs appeared to be well adsorbed by serum proteins. The PTX-coated TiO2 NPs were found to be well internalized in cancer cells as indicated by transmission electron microscopy. The intracellular aggregation of PTX-coated TiO2 NPs was assumed to occur after endocytosis leading to an entrapment of NPs in an endosomal or a lysosomal structure. Human lung carcinoma A549 cancer cells were chosen to examine their viability after the cellular uptake of the PTX-coated TiO2 NPs. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay test indicated that the cell viability should be affected by the concentration of TiO2 NPs. After applying PTX-coated TiO2 NPs (50 ppm (μg/mL)) incubating for 24 h, we observed a 30 % further decrease of cell viability for PTX alone in the low concentration range of 0.1–10 nM.