Dynamic inking of large-scale stamps for multiplexed microcontact printing and fabrication of cell microarrays

International audience; Microcontact printing has become a versatile soft lithography technique used to produce molecular micro-and nano-patterns consisting of a large range of different biomolecules. Despite intensive research over the last decade and numerous applications in the fields of biosensors, microarrays and biomedical applications, the large-scale implementation of microcontact printing is still an issue. It is hindered by the stamp-inking step that is critical to ensure a reproducible and uniform transfer of inked molecules over large areas. This is particularly important when addressing application such as cell microarray manufacturing, which are currently used for a wide range of analytical and pharmaceutical applications. In this paper, we present a large-scale and multiplexed microcontact printing process of extra-cellular matrix proteins for the fabrication of cell microarrays. We have developed a micro-fluidic inking approach combined with a magnetic clamping technology that can be adapted to most standard substrates used in biology. We have demonstrated a significant improvement of homogeneity of printed protein patterns on surfaces larger than 1 cm 2 through the control of both the flow rate and the wetting mechanism of the stamp surface during micro-fluidic inking. Thanks to the reproducibility and integration capabilities provided by microflui-dics, we have achieved the printing of three different adhesion proteins in one-step transfer. Selective cell adhesion and cell shape adaptation on the produced patterns were observed, showing the suitability of this approach for producing on-demand large-scale cell microarrays.