Cell patterning without chemical surface modification: Cell-cell interactions between printed bovine aortic endothelial cells (BAEC) on a homogeneous cell-adherent hydrogel

Cell printing offers the unique ability to directly deposit one or multiple cell types directly onto a surface without the need to chemically pre-treat the surface with lithographic methods. We utilize biological laser printing (BioLP™) to form patterns of bovine aortic endothelial cells (BAECs) onto a homogeneous cell adherent hydrogel surface. These normal cells are shown to retain near-100% viability post-printing. In order to determine whether BAECs encountered shear and/or heat stress during printing, immunocytochemical staining experiments were performed to detect potential expression of heat shock proteins (HSP) by the deposited cells. Printed BAECs expressed HSP at levels similar to negative control cells, indicating that the BioLP process does not expose cells to damaging levels of stress. However, HSP expression was slightly higher at the highest laser energy studied, suggesting more stress was present under these extreme conditions. Printed BAECs also showed preferential asymmetric growth and migration towards each other and away from the originally printed pattern, demonstrating a retained ability for the cells to communicate post-printing.