Abstract
The genome project for various biological species succeeded in sequencing species-specific genomes and derived genome information, which gave rise to a new era in biology. Biological species comprise cells in which genomic products work on each physiological system. Therefore, cells are considered as the fundamental working unit of each living system, and it is important to characterize the cells in a living system. For this purpose, we are developing a non-invasive technique to visualize cells of interest in living systems. Among various methods to analyze cells, MRI is remarkable because subjects are not disturbed by medium or drugs, and is non-invasive to biological species. However, MR cannot detect signals from small amounts of cells. Therefore, it is necessary to introduce magnetic tags to the cells of interest. To overcome the limitations of MR sensitivity, we developed an efficient method to transport MR tags (superparamagentic iron oxide; SPIO) into cells by using non-virus vehicles. MRI can detect the incorporated MR marker inside the cells non-invasively. Our aim is the in vivo development of more efficient probes for cell tracking with better sensitivity to detect targeted cells. We would show a case study about the application of this cell labeling technique to detect transplanted microglia cells in animal model of Alzheimer disease. [J Physiol Sci. 2007;57 Suppl:S22]
