Patterning of Mono- and Multi-layered Pancreatic β-cell Clusters

Cluster-size dependent behavior of pancreatic β-cells has direct implications in islet transplantation therapy for type I diabetes treatment. Control over the cluster-size enables evaluation of cluster-size dependent function, ultimately leading to the production of β-cell clusters with improved transplant efficacy. This work for the first time demonstrates the use of microcontact printing-based cell patterning of discrete two and three-dimensional clusters of pancreatic β-cells. Both single and multiple cell layers are confined to a 2D area by attaching to patterns of covalently linked laminin and not adhering to surrounding polyethylene glycol. Cell clusters were successfully formed within 24 hours for printed patterns in the range 40-120 μm, and simple modulation of the initial cell seeding density leads to the formation of multiple cell layers. Semi-quantitative fluorescence microscopy, x-ray photoelectron spectroscopy, and fourier-transform infrared spectroscopy were used to extensively characterize the surface chemistry. This technique offers exceptional control over cell cluster shape and size and provides an effective tool to study not only the cluster-size dependent behavior of pancreatic β-cells, but also has potential applicability to numerous other cell lines.