3-D Microfluidic Technique for Patterning Cells

Abstract

We developed a technology that can pattern single cells in two-dimensional space, where each cell is placed in a well-defined spot. The basis of our technique is a microfluidic system that can simultaneously capture a large number of cells from solution, position each with sub-micron precision, and transfer the patterned cells to a substrate. The critical component of the system is a polymer membrane containing a pattern of microscopic holes, whose diameters are slightly smaller than that of a single cell. One side of the membrane is immersed in a solution of cells, and gentle suction is applied from the other side. The resulting fluid flow carries cells toward the holes of the membrane. When a cell reaches the membrane, it blocks a hole. Thus, the fluid flow, along with the residual cells, is redirected toward the remaining unblocked holes, until each hole is plugged by exactly one cell. Once the membrane is laden with cells, it is brought into contact with an adhesive surface. The suction is released to transfer the cells. Repeated application of this patterning process can yield complex structures of cells of different types.Such spatial control of single cells will allow the study of intercellular interactions, as in embryogenesis and cancer. With the ability to program cell-cell interactions within and amongst multiple cell types via spatial localization, we will study how the interplay between geometry and genetics affects observed phenotype. This technique can also be used to create cellular microarrays for high-throughput data acquisition. Ultimately, we hope to build three-dimensional tissues de novo, patterned slice by slice, and cell type by cell type.