Freeform micropatterning of living cells into cell culture medium using direct inkjet printing

Abstract

Microfabrication methods have widely been used to control the local cellular environment on a micron scale. However, accurately mimicking the complexity of the in vivo tissue architecture while maintaining the freedom of form and design is still a challenge when co-culturing multiple types of cells on the same substrate. For the first time, we present a drop-on-demand inkjet printing method to directly pattern living cells into a cell-friendly liquid environment. High-resolution control of cell location is achieved by precisely optimizing printing parameters with high-speed imaging of cell jetting and impacting behaviors. We demonstrated the capabilities of the direct cell printing method by co-printing different cells into various designs, including complex gradient arrangements. Finally, we applied this technique to investigate the influence of the heterogeneity and geometry of the cell population on the infectivity of seasonal H1N1 influenza virus (PR8) by generating A549 and HeLa cells printed in checkboard patterns of different sizes in a medium-filled culture dish. Direct inkjet cell patterning can be a powerful and versatile tool for both fundamental biology and applied biotechnology.

Engineering a Model to Study Viral Infections: Bioprinting, Microfluidics, and Organoids to Defeat Coronavirus Disease 2019 (COVID-19)

“…[ 52 ] revealed that cell-laden collagen gel significantly limited the transmission of cell-free HIV and shifted it to cell-associated transmission. To fabricate complex tissue-like constructs, bioprinting is a good option[ 53 ], and bioprinted models were shown not only to be susceptible to viruses but also to recapitulate virus-associated morphological patterns similar to in vivo [ 54 , 55 ].…”

3D organ models—Revolution in pharmacological research?

“…Another bottleneck is the technical difficulty printing more than one cell type poses, for which many studies have only used a single cell type. Addressing the latter, an increasing number of publications report bioprinting of various cell types recently [37,43,44]. This approach, however, is associated with some problems such as special needs of each cell type with regard to the bioink and the necessity to establish suitable co-culture conditions after the printing itself for tissue maturation.…”

Photo-Cleavable Peptide-Poly(Ethylene Glycol) Conjugate Surfaces for Light-Guided Control of Cell Adhesion

“…The present method simply achieved cell micropatterning by exposure of the modified surface to light patterns without complicated MEMS technologies, such as micro-molds, microwells, and microstructures, and expensive machines such as ink-jet printers. Compared with other cell micropatterning methods, such as microcontact printing [27] and ink-jet printing [28], no direct access to the substrate surface is required for placing ligands or cells. Accordingly, this surface can simplify the procedure for creating a cell micropattern in a closed microdevice such as microchannels.…”