Iron oxide nanoparticle-based radio-frequency thermotherapy for human breast adenocarcinoma cancer cells.

Iron oxide nanoparticles (IONPs) with diameters of 15, 25, and 41 nm were evaluated as mediators of thermal cytotoxicity under radio-frequency (RF) exposure. The 25 nm IONPs were found to be the most efficient of the three in killing cancer cells at 350 kHz low-frequency RF irradiation. However, at a higher frequency of 13.56 MHz, 15 nm IONPs produced the highest percentage of cell death. Moreover, the killing effect was concentration-dependent in that a higher concentration of IONPs resulted in increased cellular death. Size-dependent internalization of IONPs in MCF-7 cells was quantified by using inductively coupled-plasma mass spectrometry (ICP-MS). Dark-field microscopy and transmission electron microscopy (TEM) revealed that MCF-7 cells internalize IONPs through endocytosis after 24 hours of incubation. In addition, after RF treatment, the cancer cells underwent the apoptosis process, and the level of reactive oxygen species (ROS) increased significantly after hyperthermia. Scanning electron microscopy (SEM) and TEM further established that the ultrastructure morphological changes in the cancer cells originated from the apoptosis process.

Exceptional superhydrophobicity and low velocity impact icephobicity of acetone-functionalized carbon nanotube films.

We present a simple method to produce carbon nanotube-based films with exceptional superhydrophobicity and impact icephobicity by depositing acetone-treated single-walled carbon nanotubes on glass substrates. This method is scalable and can be adopted for any substrate, both flexible and rigid. These films have indicated a high contact angle, in the vicinity of 170°, proved both by static and dynamic analysis processes. The dynamic evaporation studies indicated that a droplet deposited on the treated films evaporated in the constant contact angle mode for more than 80% of the total evaporation time, which is definitely a characteristic of superhydrophobic surfaces. Furthermore, the acetone-functionalized films showed a strong ability to mitigate ice accretion from supercooled water droplets (-8 °C), when the droplets were found to bounce off the films tilted at 30°. The untreated nanotube films did not indicate similar behavior, and the supercooled water droplets remained attached to the films' surfaces. Such studies could be the foundation of highly versatile technologies for both water and ice mitigation.