Programing Cell Assembly via Ink-Free, Label-Free Magneto-Archimedes Based Strategy

Abstract

Tissue engineering raised a high requirement to control cell distribution in defined materials and structures. In “ink”-based bioprintings, such as 3D printing and photolithography, cells were associated with inks for spatial orientation; the conditions suitable for one ink are hard to apply on other inks, which increases the obstacle in their universalization. The Magneto-Archimedes effect based (Mag-Arch) strategy can modulate cell locomotion directly without impelling inks. In a paramagnetic medium, cells were repelled from high magnetic strength zones due to their innate diamagnetism, which is independent of substrate properties. However, Mag-Arch has not been developed into a powerful bioprinting strategy as its precision, complexity, and throughput are limited by magnetic field distribution. By controlling the paramagnetic reagent concentration in the medium and the gaps between magnets, which decide the cell repelling scope of magnets, we created simultaneously more than a hundred micrometer scale identical assemblies into designed patterns (such as alphabets) with single/multiple cell types. Cell patterning models for cell migration and immune cell adhesion studies were conveniently created by Mag-Arch. As a proof of concept, we patterned a tumor/endothelial coculture model within a covered microfluidic channel to mimic epithelial-mesenchymal transition (EMT) under shear stress in a cancer pathological environment, which gave a potential solution to pattern multiple cell types in a confined space without any premodification. Overall, our Mag-Arch patterning presents an alternative strategy for the biofabrication and biohybrid assembly of cells with biomaterials featured in controlled distribution and organization, which can be broadly employed in tissue engineering, regenerative medicine, and cell biology research.

Facile and Rapid Microcontact Printing of Additive-Free Polydimethylsiloxane for Biological Patterning Diversity

“…These successful experimental demonstrations by performing so many and diverse cell patterning tests, to the best of our knowledge, were not the case for previous approaches (Table S1). ,,,,,− Also, it should be noted that most chips including ours are unable to perform nonadherent cell (e.g., lymphocyte) patterning which requires the specific chemical/biochemical interface functionalization increasing the manipulation complexity . This is not the purpose of this study, aiming to make the printing process more green, simple, and rapid.…”

“…Further, the combination of these tools with microfluidics enables high throughput and precision during the patterning process. 16 Although promising, most tools, especially external force-associated platforms, suffer from the requirement of sophisticated and cumbersome fabrication protocols and requisite auxiliary instruments such as transducers, lasers, and micropumps, limiting their wide acceptance in routine biomedical laboratories. Thus, the development of a universally adaptable (i.e., widely applicable) micropatterning methodology with user-friendly and easy-to-master manipulation is necessarily required.…”

“…The first class of methods mainly point to manipulating bioparticles (e.g., different types of cells) and are established by the optimization of structural configuration to trap and pattern particles through external forces, including mechanical/hydrodynamic, acoustic, optical, dielectrophoretic, and magnetic forces. − Alternatively, the interface guiding methods focus on manipulating cells and aqueous substances by selective adhesion/wettability and involve both micro-/nanotopographical and biochemical molecule-modified surfaces, being fabricated by electrohydrodynamic jet printing, laser micromachining, photolithography, electron beam lithography, microcontact printing, microfluidic printing, microstenciling, and so on. − The aforementioned methods have presented, to a large extent, attractive manipulating characteristics such as rapid capturing/assembling, precise positioning, and multiparallel operation. Further, the combination of these tools with microfluidics enables high throughput and precision during the patterning process . Although promising, most tools, especially external force-associated platforms, suffer from the requirement of sophisticated and cumbersome fabrication protocols and requisite auxiliary instruments such as transducers, lasers, and micropumps, limiting their wide acceptance in routine biomedical laboratories.…”

An optical nanofibre-enabled on-chip single-nanoparticle sensor

“…A potential solution is to add paramagnetic reagents to the sample. 34 In a paramagnetic medium, diamagnetic particles ( e.g. , PS particles, cells, exosomes) can be repelled from zones of high magnetic strength, bringing them close to the nanofibre.…”

4D bioprinting of programmed dynamic tissues

“…For instance, magnetic fields can be applied to assemble different cells patterns by labeling the cells with magnetic nanoparticles (e.g., gold/iron oxide nanoparticles, filamentous phages, etc.) [ 46 , 47 ] or by exploiting the innate diamagnetism of cells (i.e., the Magneto-Archimedes effect) [ 48 ]. In addition to individual cells, cell spheroids or organoids can fuse to generate organ building blocks (OBBs), and the differentiation, maturation, and 3D assembly of these OBBs can lead to the creation of functional organ-specific tissues [ [49] , [50] , [51] ].…”