Simple and Rapid Bioink Jet Printing for Multiscale Cell Adhesion Islands.

A simple and rapid process for multiscale printing of bioinks with dot widths ranging from hundreds of microns down to 0.5 μm is presented. The process makes use of spontaneous surface charges generated pyroelectrically that are able to draw little daughter droplets directly from the free meniscus of a mother drop through jetting ("p-jet"), thus avoiding time-consuming and expensive fabrication of microstructured nozzles. Multiscale can be easily achieved by modulating the parameters of the p-jet process. Here, it is shown that the p-jet allows us to print well-defined adhesion islands where NIH-3T3 fibroblasts are constrained to live into cluster configurations ranging from 20 down to single cell level. The proposed fabrication approach can be useful for high-throughput studies on cell adhesion, cytoskeleton organization, and stem cell differentiation.