Formation of a Three-Dimensional Multicellular Assembly Using Magnetic Patterning

Abstract

We demonstrate a facile approach to design three-dimensional cellular assembly of tunable size and controlled geometry with applications for tissue engineering. Three-dimensional cell patterning was performed using external magnetic forces, without the need for substrate chemical or physical modifications. Human endothelial progenitor cells and mouse macrophages were magnetically labeled using anionic citrate-coated iron oxide nanoparticles. Two magnetic tips were designed, and their magnetic field cartographies were calibrated. The focalized magnetic force generated ensured an efficient entrapment of the cells at the tips vicinity. By tuning the magnetic field gradient geometry and intensity, the magnetic cellular load, and the number of cells, we fully described the formation of the three-dimensional multicellular assemblies, and estimated the corresponding packing factor for a large range of experimental conditions.

Magnetic Assembly of Tissue Surrogates

“…For example, a cell-culture array can be fabricated by setting a pin holder device containing 6000 steel pillars on a magnet 22 . A more sophisticated device for cell manipulation is magnetic tweezers 23,24 . This technology utilizes magnetic tips with calibrated magnetic field cartographies to efficiently move cells so as to form 3D multicellular assemblies.…”

“…Several magnetic tissue-assembly techniques, such as magnetic tweezers, can be used to produce 3D tissue directly 23,24 . Multicellular spheroids (tight aggregates of hundreds of cells) are convenient building blocks for tissue reconstruction 30 .…”

De la cellule au tissu : le magnétisme auxiliaire de la biomédecine

“…La géométrie de l'assemblage multicellulaire fi nal peut ainsi être imposée de manière précise par une grande variété de paramètres, comme la géométrie de l'attracteur magnétique ou le nombre de cellules déposées (fi g. 4) [4].…”

Magnetic micro-manipulations to probe the local physical properties of porous scaffolds and to confine stem cells

“…inserted in a non magnetic support and magnetized using a permanent magnet generating a 0.32 T magnetic field [49]. This micro-magnetic device was placed at the reverse side of the scaffolds seeded with magnetically labeled cells.…”