Enhenced cell adhesion on collagen I treated parylene-C microplates

On account of unique mechanical property and inertia, parylene-C has become a promising material for microdevices especially in three-dimensional microstructures loaded with cells. However, parylene-C is not favorable for cell adhesion, and a routine procedure is to modify it with a new adhesive layer. Herein, the parylene-C substrates with or without collagen Ӏ (Col-I) coating were adopted to estimate the influence of micro-environment change on cell attachment and spreading. After modification with Col-I, cauliflower-like particles presented on the substrate surface. Contact angle was significantly decreased after Col-I modification, which suggested the surface hydrophilicity was enhanced. Furthermore, cells cultured on parylene-C surface with Col-I treatment showed increased proliferation rate and spreading areas. In order to test the adhesion strength, a series of fixed size parylene-C microplates was fabricated, and cell suspension concentration was adjusted to culture a single cell on one microplate. The microplate was folded by the autogenous shrinkage force of cell. The folding angles of parylene-C microplates with Col-I treatment exhibited higher folding angle (112.6 ± 15.6°) than untreated samples (46.7 ± 5.9°). The work proved the existence of Col-I layer was particularly important, especially in analysis of cells mechanics using parylene-C microplate as a substrate.