Analysis of the aging of cell-adhesive plasma-polymer coatings on titanium surfaces

Abstract

Plasma polymer deposition is the method of choice for the finishing of metallic implant materials like titanium with nitrogen-containing bioactive coatings. The deposited cell-adhesive plasma polymer films have to possess special properties such as homogeneity, film stability on air as well as in different media, sufficient density of functional groups and the appropriate surface charge. But also the knowledge of long-term stability is essential for the application as implant surface. Therefore, aging studies of plasma polymer coatings on titanium surfaces are important to detect the changes of surface chemistry over a longer time period. For this purpose, results of physicochemical surface diagnostics were combined with adequate tissue culture experiments. The objective of this paper was to measure surface chemical characteristics of thin plasma polymerized allylamine (PPAAm) coatings on polished titanium with the main focus on FT-IR studies over a time period of one year and to correlate these data with the adhesion of human MG-63 osteoblastic cells.