Precise Patterning of Mouse Embryonic Stem Cells on Glass Cover Slips for High-Throughput Analysis Using Laser Direct-Write

Engineering a microenvironment where the growth substrate and distance between cells are controlled is highly desirable to understand how cellular interactions affect stem cell differentiation. Laser direct-write (LDW) allows rapid and precise placement of living cells via computer-aided design/computer-aided manufacturing (CAD/CAM) control. Application of this technique to study the effects of various stem cell microenvironments on differentiation requires a high-throughput experimental setup [1]. Recently, our lab has developed a gelatin-based LDW method for the precise patterning of sensitive cell types, such as mouse embryonic stem cells (mESCs), at a resolution of about 5 μm [2]. Although viable mESCs were successfully printed with maintained pluripotency, this technique required cells to be patterned onto polystyrene Petri dishes [2,3], which may limit high-throughput efficiency. Moreover, the use of polystyrene Petri dishes requires large quantities of culture medium and is not convenient for biological analysis of mESC differentiation. Therefore, the objective of this study was to adapt the LDW method, without altering its prior success, to transfer patterns of viable mESCs to glass cover slips. However, this adaptation to cover slips could not be achieved through simple downscaling due to the unique challenges of providing sufficient moisture for viable cell transfer while maintaining pattern registry on a cover slip. Once cells have been laser patterned, cover slips can then be moved to a 24-well plate so that separate sets of laser patterned cells can be analyzed in parallel for higher experimental throughput utilizing fewer resources to maintain the cells.