Establishment of a method to determine the magnetic particles in mouse tissues
1 Beijing Institute of Pharmacoloy and Toxicology, Beijing, 100850, People’s Republic of China
2 School of Medicine, Shanghai Jiaotong University, Shanghai, 200025, People’s Republic of China
3 Department of Bio-Nano Science and Engineering, Key Laboratory for Thin Film and Microfabrication of Ministry of Education, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai, 200240, People’s Republic of China
Nanoscale Research Letters 2012, 7:665 doi:10.1186/1556-276X-7-665Published: 6 December 2012
This work is aimed to evaluate a method to detect the residual magnetic nanoparticles (MNPs) in animal tissues. Ferric ions released from MNPs through acidification with hydrochloric acid can be measured by complexation with potassium thiocyanate. MNPs in saline could be well detected by this chemical colorimetric method, whereas the detected sensitivity decreased significantly when MNPs were mixed with mouse tissue homogenates. In order to check the MNPs in animal tissues accurately, three improvements have been made. Firstly, proteinase K was used to digest the proteins that might bind with iron, and secondly, ferrosoferric oxide (Fe3O4) was collected by a magnetic field which could capture MNPs and leave the bio-iron in the supernatant. Finally, the collected MNPs were carbonized in the muffle furnace at 420°C before acidification to ruin the groups that might bind with ferric ions such as porphyrin. Using this method, MNPs in animal tissues could be well measured while avoiding the disturbance of endogenous iron and iron-binding groups.