Effect of different coated NS on cell proliferation. A. Cells were allowed to grow for 5 days on either plain glass (normal growth), plain nanosprings (NS) or NS coated with gold nanoparticles (Au), titania (TiO2), titania and gold (TiO2/Au), titania and zinc oxide (TiO2/ZnO) or titania, gold particles and zinc oxide (TiO2/Au/ZnO). The total number of live cells, as determined by calcein blue staining, was counted in five fields of view for each sample. Data were compiled from 3 independent experiments. Error bars represent standard deviation. B. Total number of live cells in five fields of view was determined for cells grown for 1, 3 or 5 days on normal growth, NS + TiO2/Au or NS + TiO2/Au/ZnO. Data were compiled from 3 independent experiments. Error bars represent standard deviation. Doubling time between 1 and 5 days was determined by dividing 96 (the total number of hours between those two time points) by the ratio of number of cells at day 5 to the same at day 1. C. Five hundred cells harvested from cultures grown for four days on normal conditions, NS + TiO2/Au or NS + TiO2/Au/ZnO were propagated on normal culture conditions for 3 days. Total number of cells in five fields of view was determined for each sample. Bars represent average of 3 independent experiments. Error bars are the standard deviation.