Novel titanium oxide nanoparticles for effective delivery of paclitaxel to human breast cancer cells

Novel titanium oxide (TiO2) nanoparticles were fabricated via a modified propanol drying step. These nanoparticles were loaded with anti-cancer drug paclitaxel (PTX) to yield PTX-TiO2 nanocomposites. The nanocomposites were characterized for their size and surface morphology employing nanoparticle tracking analysis (NTA) and scanning electron microscopy (SEM). The SEM images showed spherical particles with smooth surface and narrow size distribution of ~30–40 nm, which was also supported by NTA analysis data. The drug loading efficiency of the air-dried nanoparticles was observed to be ~63.61 % while those prepared through propanol-induced drying step showed ~69.70 %, thereby demonstrating higher efficiency of the latter. In vitro pH-dependent release of the loaded PTX was observed with higher release at acidic pH compared with physiological pH. Cell uptake studies suggested of time-dependent internalization of nanocomposites with significant improvement in uptake by increasing incubation time from 2 to 24 h, as evidenced by flow cytometry. Further, the cell viability as a measure of anti-cancer activity revealed that cell viability upon exposure to PTX only was 40.5 % while that of PTX-TiO2 nanocomposite showed 21.6 % viability after 24 h, suggesting better anti-cancer efficacy of nanocomposites. Apoptosis studies revealed that cells treated with PTX-TiO2 nanocomposites possessed more amount of apoptotic bodies as compared to those treated with PTX only.