7% and 1.5%. No significant effect of oscillating MNPs in killing cancerous cells was observed. At the concentration of 100 μg/mL, the corresponding decreasing rates were 11.7% and 30.9%, proving the morphological effect of MNPs. While at concentration of 500 μg/mL, 12.5% and 13.9% HeLa cells were killed by spherical MNPs and rod-shaped MNPs, respectively, but no significant difference was observed as well. The details of cell viability relative to AMF treatment time were shown in Figure 5. For the three HSP tumor concentrations of MNPs in this study, only the medium concentration was demonstrative of the morphological effect. For the interesting phenomenon

that medium concentration was more suitable than higher or lower ones, we assume that it could be explained by the following two aspects. Firstly, the power of the device used in this study was too low to drive MNPs in high concentrations to oscillate inside cells or tissue efficiently and simultaneously, and

selleck chemicals too many particles in AMF had mutual restraint effect if they Selleckchem Tucidinostat assembled in clusters, especially for rod-shaped MNPs. On the contrary, with low intake of MNPs, it was hard to effectively influence cell viability by mechanical oscillations. Figure 4 SEM images of rMNP-loaded cells membrane before (upper) and after (lower) 2 h AMF treatment. Figure 5 Cell viability of MNP-loaded HeLa cells after AMF treatment for a while. The corresponding morphologies and MNPs concentration in microgram per milliliter are listed on the right. It is supposed that MNPs embedded into the cell membranes mainly contributed to cell Cyclin-dependent kinase 3 death by destroying the membranes. Cell dyeing is indicative of cell membrane damage. In this study, trypan blue assay, which was sensitive to permeability of membranes, was further used to verify the observed morphological effect at the concentration

of 100 μg/mL. As shown in Figure 4, the HeLa cells that were incubated with 100 μg/mL rod-shaped MNPs appeared to have a loose cell structure after 2 h AMF treatment. For the 2-h groups, 39.47% of the rMNP-loaded cells were stained, while only 15.13% of sMNP-loaded cells were stained. Details of trypan blue staining were shown in Figure 6. This result is consistent with the observed decreases in cell viability. In a previous research, the concentration- and time-dependent damage of iron oxide MNPs to cell membrane injury was observed as well [23], supporting the concentration dependence of this study. The morphological effect was fully shown in this situation: rod-shaped MNPs pre-incubated with 100 μg/mL and placed in AMF for 2 h or more. Figure 6 Percentage of trypan blue-stained cells. These cells had been pre-cultured in 100 μg/mL MNPs suspended culture medium and exposed to an AMF for up to 2 h. Mechanisms of morphological effect The results showed that MNP morphology and concentration have an important influence on the cell inactivation effects of AMF-assisted forced vibration of MNPs.