IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Wednesday Sessions
       Session BI+SS-WeM

Paper BI+SS-WeM3
Functionalization of Metal-Oxide-Based Biomaterials and Biosensor Surfaces by Molecular Self-Asssembly Processes

Wednesday, October 31, 2001, 9:00 am, Room 102

Session: Biological Interface & Surface Science
Presenter: M. Textor, Swiss Federal Institute of Technology (ETH), Switzerland
Authors: M. Textor, Swiss Federal Institute of Technology (ETH), Switzerland
S. Tosatti, Swiss Federal Institute of Technology (ETH), Switzerland
M. Zwahlen, Swiss Federal Institute of Technology (ETH), Switzerland
S. Finken, Swiss Federal Institute of Technology (ETH), Switzerland
J.A Hubbell, Swiss Federal Institute of Technology (ETH), Switzerland
G. Haehner, Swiss Federal Institute of Technology (ETH), Switzerland
Correspondent: Click to Email
Modifications of metal oxide surfaces based on spontaneous adsorption of alkane phosphates and polycationic copolymers and subsequent film formation are shown to be potentially very useful for designing the chemical and biochemical properties of metallic implants and optical biosensors. Alkane phosphates were found to self-assemble on a number of transition metal surfaces such as titanium oxide, tantalum oxide and niobium oxide through direct coordination of the phosphate head group to high-valency metal cations. The chemical and structural properties of the adlayers were investigated using XPS, ToF-SIMS and NEXAFS. Introducing terminal functionalities other than methyl, e.g. hydroxy, amine or oligo(ethylene oxide) groups, allows one to tailor physico-chemical properties such as wettability, surface charge or the strength of protein-surface interactions. A second class of molecular assembly systems, PEG-grafted polycationic copolymers, spontaneously form monomolecular adlayers on negatively charged metal oxide surfaces, imposing high resistance towards biomolecule adsorption. Through further functionalization of the PEG-chains with biotin or peptide moieties, specific interactions of the treated oxide surface with streptavidin or with cell receptors can be induced while preserving the low degree of non-specific events. w-functionalized alkane phosphate SAMs, as well as peptide-modified PEG-grafted copolymers have been applied to both smooth and rough titanium surfaces to produce model surfaces for the study of fibroblast and osteoblast cell-surface interactions, with independent control of surface topography and chemistry. Furthermore, the two novel molecular assembly systems are shown to have a substantial potential for the reproducible and cost-effective modification of chips in optical-waveguide-based bioaffinity sensing of proteins and of DNA/RNA, including their application to microarray-type sensor surfaces.