Preparation of L929 Cell Array by Magnetic Pin Holder Device for Single Cell Function Analysis

Abstract

A cell array has been developed for single cell analysis with magnetic cell labeling method using the unmodified colloidal magnetic nanoparticles (magnetite particle with 10 nm diameter). When the magnetic nanoparticles were dispersed in the medium for cell labeling, these particles aggregate to micrometer order sizes. However, when these particles were dispersed in a sucrose solution, above 80% of these particles maintained their size below 100 nm and their dispersibility was kept for at least two weeks. When mouse pulmonic fibroblasts L929 were exposed to the magnetic nanoparticle suspension of a 0.3 M isotonic sucrose solution for 10 min, it was found that the magnetic nanoparticles were taken into the cells at approximately 1.1 pg-Fe/Cell This method was demonstrated without modifying the magnetic nanoparticles, and a variety of cells could be labeled magnetically. It was found that this magnetic labeling method did not influence the cell response to cytokine, TNF-α α α α α. The magnetic induction by means of a pin holder device, which is made from magnetic soft iron and contains more than 6000 pillars on its surface, enabled the arrangement of the magnetically labeled cells in arrays. In addition, the method was used to monitor the time course of the responses of L929 cells to TNF-α α α α α in a single cell array. The change in the stages of apoptosis such as phosphatidylserine externalization and propidium iodide uptake was detected using fluorescent microscopy.

Three-dimensional cell culture array using magnetic force-based cell patterning for analysis of invasive capacity of BALB/3T3/v-src

“…Since the magnetite particles used for cell labeling has little autofluorescence, the prepared cell culture array is compatible with fluorescent studies. [26][27][28] The effect of pharmacologically and physiologically active agents is that morphological alteration can be monitored in a controlled micropatterned cell environment using genetically modified cells, donor tissues, primary cells, and/or cell lines. In this study, the effect of MMP inhibitors was successfully monitored in 3D although such change in cell behavior was not observed in 2D (Fig.…”

“…24 Magnetic force-based cell patterning could also arrange cells in an array platform. [25][26][27][28] The hybrid system consists of an integrated circuit with a microcoil array circuit that produces spatially patterned microscopic magnetic fields and a microfluidic system fabricated on top. The microfluidic system provides a biocompatible system with rapid configuration of the field pattern made by the integrated circuit for manipulation of magnetic bead-bound cells.…”

“…Magnetism can be concentrated on the pillar part by magnetizing this device. We succeeded in allocation of magnetically labeled cells at a single cell level 26,28 as well as at several cells level, 27 and cell function analysis were performed by varying the cell seeding density using this device. Magnetically labeled human umbilical vein endothelial cells were successfully arranged by using the pin holder type device for fabricating the cell arrays.…”