Gelatin methacrylate as a promising hydrogel for 3D microscale organization and proliferation of dielectrophoretically patterned cells

Abstract

Establishing the 3D microscale organization of cells has numerous practical applications, such as in determining cell fate (e.g., proliferation, migration, differentiation, and apoptosis) and in making functional tissue constructs. One approach to spatially pattern cells is by dielectrophoresis (DEP). DEP has characteristics that are important for cell manipulation, such as high accuracy, speed, scalability, and the ability to handle both adherent and non-adherent cells. However, widespread application of this method is largely restricted because there is a limited number of suitable hydrogels for cell encapsulation. To date, polyethylene glycol-diacrylate (PEG-DA) and agarose have been used extensively for dielectric patterning of cells. In this study, we propose gelatin methacrylate (GelMA) as a promising hydrogel for use in cell dielectropatterning because of its biocompatibility and low viscosity. Compared to PEG hydrogels, GelMA hydrogels showed superior performance when making cell patterns for myoblast (C2C12) and endothelial (HUVEC) cells as well as in maintaining cell viability and growth. We also developed a simple and robust protocol for co-culture of these cells. Combined application of the GelMA hydrogels and the DEP technique is suitable for creating highly complex microscale tissues with important applications in fundamental cell biology and regenerative medicine in a rapid, accurate, and scalable manner.

Inkjet‐bioprinted acrylated peptides and PEG hydrogel with human mesenchymal stem cells promote robust bone and cartilage formation with minimal printhead clogging

“…However, the bioink viscosity increased significantly by mixing 1.5% GelMA to the PEG solution, which created a major hurdle for inkjet bioprinting with frequent clogging. The 5% GelMA solution was not printable, although 10% GelMA is the common concentration for tissue engineering applications [57,58]. In contrast, the viscosity of 10% PEG was similar to that of regular ink.…”

Controllable Patterning of Different Cells Via Optical Assembly of 1D Periodic Cell Structures

“…Compared with the previously reported cell patterning methods, such as microcontact printing, [ 8 ] lithography, [ 9 ] inkjet printing, [ 10 ] dielectrophoresis, [ 11 ] and electrochemical desorption, [ 12 ] the main advantages of our method are 1) the method is very simple with only a single ATF and a laser source, without the need of elaborately fabricated substrates of electrodes to predetermine the locations of cell patterns; 2) the patterning offers single-cell precision and control; 3) cells of different types can be controllable positioned into designated locations, forming cell structures with periodic confi gurations via direct cell-cell contact; 4) the patterned cell structures can be fl exibly moved in 3D to designated locations; 5) the optical signal propagating along the cell structures can be detected in real-time. Compared with the optical trapping method using optical tweezers for cell patterning by trapping multiple cells, [ 16 ] the main advantages of this method are setup simplicity and manipulation fl exibility.…”

“…[ 6,7 ] Until now, different techniques have demonstrated the ability for cell patterning by immobilizing cells on designated regions of a surface. For example, cell patterning has been achieved by using microcontact printing [ 8 ] or lithography [ 9 ] to defi ne the locations of cell attachment, inkjet printing [ 10 ] to place cells pixel by pixel on a substrate, dielectrophoresis [ 11 ] to use dielectrophoretic forces to concentrate cells into specifi c locations, and electrochemical desorption [ 12 ] to use electrochemically constrained surface changes to attach cells. In addition, by cooperating with microcontact printing, orthogonal engineering matrix can be used to regulate multicellular morphology, which suggests important ways in developing implantable materials via cell patterning.…”

The trend towards in vivo bioprinting

“…[34][35][36] . Recent advances indicate that by choosing proper parameters, relatively high viability of the encapsulated cells could be achieved in photo-patterning or bioprinting process [37,38] . More importantly, naturally-derived hydrogels like methacrylated gelatin exhibited comparable biological properties with collagen to support the encapsulated cells' distribution and growth in both in vitro and in vivo studies [39][40][41] .…”