Magnetic levitation of single cells

Abstract

Several cellular events cause permanent or transient changes in inherent magnetic and density properties of cells. Characterizing these changes in cell populations is crucial to understand cellular heterogeneity in cancer, immune response, infectious diseases, drug resistance, and evolution. Although magnetic levitation has previously been used for macroscale objects, its use in life sciences has been hindered by the inability to levitate microscale objects and by the toxicity of metal salts previously applied for levitation. Here, we use magnetic levitation principles for biological characterization and monitoring of cells and cellular events. We demonstrate that each cell type (i.e., cancer, blood, bacteria, and yeast) has a characteristic levitation profile, which we distinguish at an unprecedented resolution of 1 × 10. We have identified unique differences in levitation and density blueprints between breast, esophageal, colorectal, and nonsmall cell lung cancer cell lines, as well as heterogeneity within these seemingly homogenous cell populations. Furthermore, we demonstrate that changes in cellular density and levitation profiles can be monitored in real time at single-cell resolution, allowing quantification of heterogeneous temporal responses of each cell to environmental stressors. These data establish density as a powerful biomarker for investigating living systems and their responses. Thereby, our method enables rapid, density-based imaging and profiling of single cells with intriguing applications, such as label-free identification and monitoring of heterogeneous biological changes under various physiological conditions, including antibiotic or cancer treatment in personalized medicine.

A high throughput approach for analysis of cell nuclear deformability at single cell level

“…4). One of the studies showed that metastatic lung, breast and pancreatic cancer cells were 70% softer than benign cells31 and cancer cells over all have lower densities65. Nucleus stiffness also follows a similar trend; loss of Lamin A/C during carcinogenesis leads to a decrease in the stiffness and an increase in the elasticity of the nucleus66.…”

Tilted Magnetic Levitation Enables Measurement of the Complete Range of Densities of Materials with Low Magnetic Permeability

“…iii) MagLev can be used to perform a range of important, density-based bioanalyses. [13][14][15][16][17] iv) The simplicityof-use, portability, and low cost of MagLev make it particularly attractive for use in resource-limited settings (e.g., schools, mines, archeological sites, field operations, and laboratories in the developing countries).…”

Patterning of tissue spheroids biofabricated from human fibroblasts on the surface of electrospun polyurethane matrix using 3D bioprinter

“…Finally, using magnetically functionalized electrospun matrices with magnetic nanoparticles [23] as well as using tissue spheroids biofabricated from cells labelled with magnetic nanoparticles [24][25][26][27] will enable the development of novel magnetic 3D bioprinting technology based on principles of magnetic levitation or translocation of tissue constructs using magnetic forces [28][29][30] .…”

“…It has been demonstrated that tissue spheroids can attach, spread and fuse on synthetic electrospun matrices [21,22] . Moreover, recently reported magnetic functionalization of electrospun synthetic matrices with magnetic nanoparticles [23] as well as biofabrication of tissue spheroids from cells labelled with magnetic nanoparticles [24][25][26][27] allow the development of magnetic forcesdriven biofabrication and even 3D magnetic bioprinting based on principles of magnetic levitation [28][29][30] . Thus, application of nanotechnology can enable development of novel technology of magnetic 3D bioprinting.…”