Long-Term Stable Poly(acrylamide) Brush Modified Transparent Microwells for Cell Attachment Studies in 3D

The fabrication of 3D cell microenvironments exploiting versatile, long-term stable passivating poly(acryl amide) brushes in a microwell format and the study of the behavior of fibroblast and pancreatic tumor cells in wells of systematically varied shape and size is reported. The microwells, which are obtained by combining micromolding in capillaries with microcontact printing of initiator monolayers for subsequent surface-initiated polymerization of acrylamide and controlled functionalization with fibronectin (FN), expose cell adhesive areas inside the wells and protein and cell resistant brushes on the topside plateaus. NIH 3T3 fibroblast and pancreatic tumor (Patu 8988T) cells adhere and remain viable in the FN coated microwells for more than 1 week. Compared to 2D patterns, both cell lines are observed to attach to the bottom as well as the sidewalls of the microwells. The cytoskeleton alignment is found to be less pronounced compared to 2D patterned substrates, independent of microwell size and geometry.