Magnetophoretic Micro‐Distributor for Controlled Clustering of Cells

Abstract

Cell clustering techniques are important to produce artificial cell clusters for in vitro models of intercellular mechanisms at the single‐cell level. The analyses considering physical variables such as the shape and size of cells have been very limited. In addition, the precise manipulation of cells and control of the physical variables are still challenging. In this paper, a magnetophoretic device consisting of a trampoline micromagnet and active elements that enable the control of individual selective jumping motion and positioning of a micro‐object is proposed. Based on a numerical simulation under various conditions, automatic separation or selective clustering of micro‐objects according to their sizes is performed by parallel control and programmable manipulation. This method provides efficient control of the physical variables of cells and grouping of cells with the desired size and number, which can be a milestone for a better understanding of the intercellular dynamics between clustered cells at the single‐cell level for future cell‐on‐chip applications.

Tailoring matter orbitals mediated using a nanoscale topographic interface for versatile colloidal current devices

“…The optimized mechanical mode enables the selective control of the target particles without additional elements, such as the application of z -field, current, and programmed three-dimensional fields, that influence the movement of all non-target particles simultaneously under a magnetic field for the desired control. 39,41,44,48,49 Herein, we demonstrated a four-step basic and two-step additional manipulation combined with the mode from symmetry breaking, as shown in Fig. 6.…”

“…The detailed conjugation processes of the magnetic particles with the nonmagnetic polystyrene particles are described in an earlier paper. 44 Briefly, 2.8 μm (M-270 carboxylic acid and M-280 streptavidin, Invitrogen, Grand Island, NY, USA) diameter of superparamagnetic particles were bound with 6.72 μm diameter nonmagnetic polystyrene particles (aminopolystyrene beads, AP-60-10, SPHERO). The washed magnetic particles with a 0.05 M 2-( N -morpholino) ethanesulfonic acid (MES) buffer solution (pH = 5), polystyrene particles (0.2% w/v), and 5 mM N -(3-dimethylaminopropyl)- N ′-ethylcarbodiimide hydrochloride (EDC) were added to a 0.05 M MES buffer solution with a total volume of 0.5 mL.…”

“…Because 2D thin-film structures do not affect topography formation, and driving forces around the local landscape are independent to each target. Therefore, the magnetophoretic circuit concept [36][37][38][39][40][41][42][43][44][45] using thin-film patterns is most suitable for investigating topographic effects among magnetic field-based technologies. The magnetophoretic circuit allows the particles to continuously move according to the magnetic energy distribution of the micro-magnets without additional fluid flow.…”

Integrated Microfluidics for Single‐Cell Separation and On‐Chip Analysis: Novel Applications and Recent Advances

“…• Micro-patterning of magnetic microsources to establish localized, high magnetic fields [54][55][56][57] • Magnetic microtweezers for single cell manipulation [57] • Negative selection of non-targeted cells [60] • Magnetomicrofluidic circuits for spatial single cell control [254,255] • Use of alternating magnetic fields for advanced particle movement [62] Acoustophoresis • Label-free, contact-free separation [63] • Large operation/penetration distances [21] • Large volume and high-throughput processing [63] • Application independent of properties like pH, ionic strength, or charge [64] • Bulk piezoelectric transducers pose geometric limitations to integration [68] • Less sensitive sample discrimination than on dielectric polarizability [21] • Cell manipulation efficiency influenced by the properties of the medium and the microfluidic channel geometry [65,66] • Requires the use materials with high specific acoustic impedances relative to the fluid [70] • Most effective for the manipulation of spherical cells [75] • Applications of acoustophoretic principles in polymer-based platforms. [66,[70][71][72] • Size-independent cell separation via isoacoustic focusing [75] • Generation of 2D acoustic standing waves in microchannels to focus non-spherical cells [76] • Acoustic cell washing [77,78] • Use of secondary acoustic radiation forces or acoustic streaming to manipulate single-cell motion [81,82,84] Optical Tweezers • Label-free, contact-free separation [86,95,256] • High force resolution [86] • Application possible both in flow and static conditions…”