Gelatin methacrylamide as coating material in cell culture

Unmodified gelatin (uG) is widely used as a coating material in cell culture for improving surface properties. In this study, the authors investigated if gelatin methacrylamide (GM) with a medium degree of methacrylamide modification (GM1.5) and a high degree of methacrylamide modification (GM4) are equally suitable for this purpose. Therefore, goldsurfaces were coated with uG, GM1.5, and GM4 by adsorption of the polymers on the surfaces.Coating success was confirmed by spectroscopic ellipsometry, contact angle measurements,surface plasmon resonance spectroscopy (SPRS), and atomic force microscopy (AFM). The authors found that upon adsorption of uG, GM1.5, a nd GM4 on gold, thin films with thicknesses of 2.95 nm, 2.50 nm, and 2.26 nm were formed. The coatedsurfaces showed advancing contact angles of 46° (uG and GM1.5) and 52° (GM4) without alteration of the surface roughness determined by AFM. Proteinadsorption taking place on the coatedsurfaces was measured during contact of the surfaces with fetal calf serum by SPRS. Proteinadsorption on the coatedsurfaces was reduced by the factor of 6.4 (uG), 5.4 (GM1.5), and 4.6 (GM4) compared to goldsurfaces. Human fibroblasts cultured on the surfaces showed excellent viability shown by water soluble tetrazolium salt assay as well as live/dead staining with propidium iodide and fluorescein diacetate. No cytotoxic effects of the GM coatedsurfaces were observed, giving rise to the conclusion that GMs are suitable materials as coatings in cell culture.