A plasma-deposited surface for cell sheet engineering: Advantages over mechanical dissociation of cells

Previously, we compared the release of cell sheets via low-temperature liftoff from ppNIPAM treated surfaces to cell removal by enzymatic digestion and mechanical dissociation. We made two interesting observations, namely: 1) mechanical dissociation of cells from surfaces leaves behind a surface that promotes new cell growth, and 2) that ToF-SIMS data from post-mechanical dissociation surfaces differed from the other surfaces primarily due to the presence of hydrocarbon species and a fragment at m/z = 86 which could be attributed to either amino acids (leucine/isoleucine) or lipid molecules. In this study, we examine in detail the effect that mechanical dissociation has on cell removal. Using PCA of the ToF-SIMS data, we observe a clear separation of the post-mechanical dissociation surfaces from controls. We find that post-mechanical dissociation surfaces are primarily characterized by the presence of high mass fragments (indicative of lipid molecules), and the absence of certain low mass fragments indicative of protein. These findings support the hypothesis that the process of mechanical disruption ruptures cell walls, leaving lipid molecules from the cell membrane on the surface.