Efficient creation of cellular micropatterns with long-term stability and their geometric effects on cell behavior

Cellular micropatterning with bio-adhesive and nonadhesive areas has attracted increasing interest for the precise design of cell-to-surface attachment in cell biology studies, tissue engineering, cell-based biosensors, biological assays, and drug development and screening. In this paper we describe a simple and efficient method to create a two-dimensional stable cellular microenvironment, which is based on (1) forming a protein-resistant oligo(ethylene glycol) methyl ether methacrylate polymer layer on the substrates via surface-initiated atom transfer radical polymerization; (2) placing a defined photomask on the substrate and exposing the substrate to ultraviolet light; and (3) immersing the patterned surface in a fibronectin solution to form cell-adhesive protein patterns in a cell-resistant background. The resulting surfaces are tailored into cell-adhesive and cell-resistant regions. Three different types of cells (NIH-3T3, PC12, bone marrow-derived mesenchymal stem cells) are seeded on such patterned surfaces to form cellular patterns. The geometric effects on cell behavior are investigated. The long-term stability is tested by NIH-3T3 fibroblasts and mesenchymal stem cells and excellent retention of cellular patterns is observed. The strategy illustrated here offers an efficient way to create a stable, patterned cellular microenvironment, and could be employed in tissue engineering to study the effect of micropatterns on the proliferation and differentiation of cells, and in particular mesenchymal stem cells.