earticle

영어

Microengineering techniques such as lab-on-a-chip technologies are emerging as the next revolution in tools for high throughput cell-based analysis. Cell is the basic unit of life of all organisms and exerts its function by pericellular microenvironment, such as extracellular matrix and other cells adjacent to individual cells. Therefore, to understand, control and predict cellular responses, it is important to build the biomimeticevaluation system. With the development of micro-and nano-technology devices, variety of tools is becoming available for the analysis of cells at the cellular and molecular levels. Since single-cell analysis enables to capture the minimal change within a living organism, it is emerging as less-invasive approach for clinical diagnosis and cell identification. In this study, we developed technologies using magnetic nanoparticles for cellular analysis of individual cells, such as magnetic force-based cell patterning and droplet-based gene expression analysis. Using these methods, the behavior of cancer cells was observed a in the three-dimensional cell culture array along with gene expression analysis.Magnetic force-based cell patterning was conducted using a pin-holder device fabricated by processing electromagnetic soft iron in which each pillar is aligned at center-to-center distance of 250 μm for magnetic convergence. Using this pin-holder device with Nd-B magnet underneath, magnetically labeled cells were allocated on the cell culture dish at single and multiple cells levels by varying the cell seeding density. The magnetic cell patterning technique has been applied for evaluation of invasive capacity with tumor cells in a three dimensional cell culture array, and cell susceptibility assay was performed. Also, a droplet manipulation system using superparamagnetic nanoparticles and magnetic force was developed for gene expression analysis at single cell levels. The magnetic force-based-droplet handling system can be used as a powerful tool for various biochemical applications by moving and coalescing sample droplets using magnetic beads immersed in mineral oil. We optimized the conditions for single cell lysis and RT-PCR analysis and applied this system for detection of Wilms tumor gene mRNA, that is useful as an indicator of minimal residual disease in leukemia. The developed system is quite simple and allows for the handling of droplets and preceding reactions using a magnet without external pumps and valves. These systems are greatly advantageous for cell analysis and related diagnostic applications.