Patterning of human cord blood-derived stem cells on single cell posts and lines: Implications for neural commitment.

Using stem cells (SC) in new strategies for clinical treatment requires control of stem cell fate decision and the ability to govern their patterning and commitment in tissue engineering. Neural stem cells and other adult SC can respond to the different components of the microenvironment and their spatial arrangement in the stem cell niche. It has been shown previously by our group that different composition and architecture of patterned bioactive domains influence the developmental response of neural stem cells. In the present report we verify the commitment and differentiation of neural stem cells derived from human cord blood (HUCB-NSC) by a single cell patterning system. Microcontact printing technology was used to generate single cell positioning areas of different geometry: 10 micrometer-thin lines and 10 micrometer-width one cell posts. The commitment and differentiation of HUCB-NSC cells cultured on different surfaces were dependent on the geometry and the type of biomaterial present in bioactive domains. Fibronectin promoted neuronal protrusion outgrowth (Beta-tubulin III and MAP-2 positive cells) and gap junction development (Cx43 marker) between cells growing on lines while poly-L-lysine promoted HUCB-NSC differentiation into astrocytic, glial fibrillary acidic protein expressing (GFAP positive) cell phenotype. Here we also demonstrate by scanning electron microscopy that morphology of cells on the patterned surface is highly dependent upon the type of biomolecules used for printing. These kinds of platforms can be used for investigating the influence of spatial organization of environment on the SC fate decision and for studying the molecular processes occurring in a single cell.