Characterization and analysis of osteopontin-immobilized poly(2-hydroxyethyl methacrylate) surfaces

A wide array of technologies exist for the characterization and quantification of molecules present at surfaces. We have used several of these experimental and instrumental techniques for the analysis of a novel biomaterial surface. Osteopontin, an extracellular matrix molecule involved in wound‐healing processes, has been chosen as a relevant model protein to immobilize onto poly(2‐hydroxyethyl methacrylate) [poly(HEMA)]. Electron spectroscopy for chemical analysis and time‐of‐flight secondary ion mass spectrometry were used to verify the surface chemistry and the presence of protein. Iodination of osteopontin yielded quantitative data supportive of dose‐dependent immobilization. Enzyme‐linked immunosorbent assay was also used to investigate the presence of osteopontin on poly(HEMA). Finally, the cell adhesive properties of immobilized osteopontin were confirmed by using a bovine aortic endothelial cell adhesion assay. The use of multiple tools to characterize the many facets of a biomaterial surface will undoubtedly improve our understanding of the surface and facilitate the amelioration of in vivo performance. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 334–343, 2003