Overendocytosis of superparamagnetic iron oxide particles increases apoptosis and triggers autophagic cell death in human osteosarcoma cell under a spinning magnetic field.

The toxicity of superparamagnetic iron oxide nanoparticles (SPIONs) is still a vital topic of debate and the mechanisms remain unclear. In the present study, overdose SPIONs could induce osteosarcoma cell death and the effects were exaggerated when combined with spinning magnetic field (SMF). In the combination group, mitochondrial transmembrane potential decrease more obviously and reactive oxygen species (ROS) was found to generate much higher in line with that of the apoptosis ratio. Meantime, amount of autophagy was induced. Inhibiting the autophagy generation by 3-methyladenine (3-MA) increase cell viability but decrease the caspase 3/7 and caspase 8 activities in combination groups, and inhibiting apoptosis took the same effect. In the end, the SPIONs effects on xenograft mice was examed by intratumoral injection. The result showed that the combination group could greatly decrease the tumor volume and prolong the lifespan of mice. In sum, the result indicated that overdose SPIONs induced ROS generation, and excessive ROS induced by combination of SPIONs and SMF contribute to autophagy formation, which play a apoptosis-promoting role that formed as a platform to recruits initiate the caspase activities.

The data of GDP and exchange rate used in the Balassa-Samuelson hypothesis.

This article introduces the data of the log real GDP per capita ratio and the log real exchange rate which are used to revisit the Balassa-Samuelson Hypothesis. We acquired the data from IMF and World Bank database, and provide the name and source of the data. All data are openly accessible. Besides, we describe the value of data as well as the method to process the data which can also be found in "The Balassa-Samuelson Hypothesis in the developed and developing countries revisited" (Weiguo Wang, Jing Xue, Chonghua Du, 2016) [1].