With the rapid development of nanotechnology and increasingly broad bio-application of engineered nanomaterials, their biohazards have become a serious public concern. It is believed that the chemical nature, particle size, morphology, and surface chemistry of nanomaterials are key parameters that influence their toxicity. Although cultured cells have been widely used to evaluate nanomaterial toxicity, it remains unclear whether the passage of these cells affects the evaluation results. In the present study, Ba/F3 cells transfected with the BCR-ABL gene were subcultured to study the effect of passage number on cell stability and their cellular responses upon exposure to nanomaterials. The results demonstrated that proliferation, cellular senescence, BCR-ABL gene expression, cell cycle and apoptosis were stable across multiple passages. Senescence and BCR-ABL gene expression of cells from different passage cells were unchanged when treated with silver nanoparticles (AgNPs). In addition, the cells at multiple passage numbers were all arrested in the G 2 /M phase and apoptosis was induced by the AgNPs. These nanoparticles could enter cells via endocytosis and localize in the endosomes, which were also not influenced by passage number. These data suggest that short-term passage would not affect cultured cell stability and toxicity assessment using these cells would be consistent when maintained appropriately.
GUO DaWeiZHANG XiuYanHUANG ZhiHaiZHOU XueFengZHU LingYingZHAO YunGU Ning
Encapsulated gas microbubbles are well known as ultrasound contrast agents (UCAs) for medical ultrasound (US) imaging. With the development of shell materials and preparation technologies, the application of microbubbles has been enormously popular in molecular imaging, drug delivery and targeted therapy, etc. The objective of this study is to develop Fe3O4 nanoparticle-inclusion microbubble construct. The in vitro US imaging experiment indicates that the Fe3O4 nanoparticle-inclusion microbubbles have higher US enhancement than those without Fe3O4 nanoparticle-inclusion. According to the microbubble dynamic theory, the acoustic scattering properties can be quantified by scattering cross-section of the shell. The scattering study on Fe3O4 nanoparticle-inclusion microbubbles of different concentration shows that within a certain range of concentration, the scattering cross-section of microbubble increases with the addition of Fe3O4 nanoparticles. When exceeding the concentration range, the ultrasonic characteristic of microbubbles is damped. On the other hand, since Fe3O4 nanoparticles can also serve as the Magnetic Resonance Imaging (MRI) contrast agent, they can be potentially used as contrast agents for the double-modality (MRI and US) clinical studies. However, it is important to control the concentration of Fe3O4 nanoparticles in the shell in order to realize the combined functions of US and MRI.
The development of nanobiology requires a fundamental understanding of the interaction features between light and cells as well as cells containing nanoparticles. In this study, the generalized multiparticle Mie (GMM) theory was employed to calculate the scattering properties of cells under refractive index matching conditions. The angular distribution of scattered light is statistically averaged to obtain a good fit for the experimental results. Based on a simplified cell model, the variabilities between the scattered light pattern of normal cells and that of cancerous cells were examined. The results indicate that the small angle scattering is sensitive to the organelle distribution, which could be applied in the diagnostics of cancerous cells. Finally, the effects of cellular uptake of nanoparticles on the scattering pattern was also investigated.
