Although significant advances have been made in the development of biocompatible materials, currently available biomaterials still present a number of problems for in vivo applications. One of the attempts to improve the biocompatibility, especially blood-compatibility, of biomaterials has been surface modification. Typically, poly(ethylene glycol) (PEG), albumin, heparin, and phospholipid molecules are grafted to the surface to prevent protein adsorption and cell adhesion. We have been modifying biomaterial surfaces by covalent grafting of PEG and albumin. The control and modified surfaces were examined using an atomic force microscope (AFM). In this study, we examined the surface topography changes by surface modification using PEO grafting to glass as a model system.

Glass surfaces were modified with PEO using (N-triethoxysilylpropyl)-Omonomethoxy PEG urethane (PEG-Si), a PEG derivative containing a hydrophobic carbon chain and triethoxysilyl group at one end of the PEG chain. The presence of the hydrophobic carbon chain allowed self-assembly on the surface and triethoxysilyl resulted in covalent bonding to glass surfaces