Primary and Stem Cell Microarrays: Application as Miniaturized Biotesting Systems.

The deposition of living cells on microarray surfaces can be used to create physiologically relevant architecture in vitro. Such living cell microarrays enable the reconstruction of biological processes outside the body in a miniaturized format and have many advantages over traditional cell culture. The present protocol offers an option for the preparation and analysis of living primary and stem cell-based microarrays utilizing the standard microarray equipment (contact-free piezoelectric nanoprinter, microarray scanner), as well as microscopy. To produce living cell microarrays, we applied two kinds of mesenchymal stem cells (MSCs) isolated from umbilical cord and adipose tissue, as well as human umbilical vein endothelial cells (HUVECs) as model cells. We used live imaging microscopy for the online monitoring of cell spots in total size, staining of viable cells with Calcein acetoxymethyl ester (Calcein-AM) and treatment of MSCs with differentiation media to analyze the proliferation, viability, and differentiation potential of printed cells. This way, the general applicability of the established living cell-based microarray production was demonstrated.