High‐Throughput Differentiation of Embryonic Stem Cells into Cardiomyocytes with a Microfabricated Magnetic Pattern and Cyclic Stimulation

Abstract

Pluripotent stem cells are central tools to many regenerative medicine strategies due to their ability to differentiate towards the three embryonic germ layers. One challenge remains in providing control over their differentiation into specific lineage, such as cardiac commitment. Here, the possibility of directing cardiomyogenesis of embryonic stem cells (ESCs) using a microfabricated magnetic pattern is demonstrated. The stem cells are labeled with magnetic nanoparticles, aggregated into embryoïd bodies (EBs) onto the pattern, and stimulated with a local magnetic force applied via the pattern. The EBs formed on this magnetic device experience the same differentiation profile than the ones created by the common hanging drop approach, while it allows high-throughput production of hundreds of EBs. Further on/off cyclic magnetic force stimulation mediated by the same device is sufficient to enhance cardiomyogenesis in a way that almost all EBs develop spontaneous beating, confirmed by the overexpression of -actin and troponin proteins, and by the upregulation (2 to 5-fold) of genes involved in mesoderm differentiation (Nkx2.5, Gata4, and Gata6), and more specifically cardiac lineage (Tnnt2, Myh6 and Myl-2). Beyond holding high application-level potential, this work confirms that physical forces, and specifically on/off dynamic ones can be sufficient to govern cell function. Received: ((will be filled in by the editorial staff)) Revised: ((will be filled in by the editorial staff))

Ever-Evolving Identity of Magnetic Nanoparticles within Human Cells: The Interplay of Endosomal Confinement, Degradation, Storage, and Neocrystallization

“…Data from ref 56 (e) Magnetic cell patterning can be achieved on arrays, with cells immediately attracted to the surface where the magnetic micro-tips are positioned. Data from ref 4 (f-g) Different tissue shapes can be achieved such as cell-sheets (f), or rings (g), reproduced with permission from refs 58 and 59 , respectively, copyright 2007 and 2020 John Wiley & Sons. (h) Cell assembly formed after magnetic levitation.…”

Iron Oxide Mediated Photothermal Therapy in the Second Biological Window: A Comparative Study between Magnetite/Maghemite Nanospheres and Nanoflowers

“…Iron oxide magnetic nanoparticles (MNPs), such as magnetite (Fe 3 O 4 ) and its oxidized form maghemite (γ-Fe 2 O 3 ), emerged as promising nanotheranostic agents due to their versatile magnetic properties, their biocompatibility, and their biodegradability [1]. Consequently, MNPs have made their way into different applications in the biomedical field including, among others, MRI contrast agents [2], drug delivery [3], tissue engineering [4,5], magnetic targeting [6][7][8][9], and as heat mediators in magnetic hyperthermia (MHT) cancer therapy [10,11]. Unlike other thermal nanotherapies, MHT can be used non-invasively at any depth in tissues, but it still suffers from major restrictions mainly due to the low yield of heat generated per mg. Consequently, several approaches have been suggested to overcome these limitations: among them, one is based on the synthesis of novel nanostructures having an optimized heating [12][13][14]; another consists of the association of MNPs with other heat-generating materials, such as plasmonic ones, specifically designed for photothermal (PT) therapy, resulting in a multifunctional magneto-plasmonic nanohybrid platform.…”

Transient cell stiffening triggered by magnetic nanoparticle exposure

“…Indeed, modern biophysics is more and more focused on the role of physical features and stimuli on cell functions, phenotypic orientation and differentiation. For example, the rigidity of the substrate or mechanical stresses such as cyclic ones can be sufficient to induce differentiation of multipotent or pluripotent stem cells, and local mechano-transduction can also induce differentiation [ 24 ]. Regardless, direct biophysical probing studies at the cell level of the impact of nanoparticle uptake on cells remains rare.…”