Imaging the distribution of magnetic nanoparticles on animal bodies using scanning SQUID biosusceptometry attached with a video camera

To image magnetic nanoparticles (MNPs) on animal bodies, physicians often use magnetic resonance imaging to determine the superparamagnetic characteristics of MNPs during preoperative analysis. However, magnetic resonance imaging is unsuitable for other biomedical applications, such as the curative surgical resection of tumors or pharmacokinetic studies of MNPs, because of the requirement of nonmetal environments and high financial cost of frequent examination, respectively. Thus, researchers have proposed other nonmagnetic imaging technologies, such as fluorescence, using multimodal MNPs with nonmagnetic indicators. The development of a magnetic instrument based on the other magnetic characteristics of MNPs avoids the disadvantages of multimodal MNPs, including the biosafety risk. On the basis of the alternating current susceptibility of MNPs, previous research has demonstrated the magnetic examination of scanning superconducting-quantum-interference-device biosusceptometry (SSB). This study, using a low-noise charge-coupled-device type of a video camera, reports the integration of SSB and charge-coupled-device to immediately image the magnetic signals on animal bodies or organic tissue. This real-time imaging by SSB increases the usefulness of MNPs for more clinical applications, including the imaging-guided curative surgical resection of tumors.