The application of gas discharge plasmas for different functionalization and coating strategies is discussed with respect to cell adhesion to polymeric and metallic surfaces. Poly(ether ether ketone) (PEEK) and titanium (Ti) were selected as typical bone cell-contacting biomaterials. The surfaces were equipped with nitrogen-based chemical functionality, mainly amino groups. The behavior of human MG-63 osteoblasts was investigated with respect to cell adhesion and growth on plasma-treated PEEK and Ti surfaces. MG-63 cells adhere faster and occupy a wider cell area on the plasma-treated compared to untreated surfaces, which is not integrin receptor mediated. Although different plasma treatments were applied to functionalize polymeric and metallic surfaces with amino groups, similar cell adhesion properties were achieved. (C) Koninklijke Brill NV, Leiden, 2010