AVS 52nd International Symposium
    Biomaterial Interfaces Thursday Sessions
       Session BI2-ThM

Paper BI2-ThM9
Synthetic Glycopolymers as Scaffolds to Study Multivalent Carbohydrate Interaction at Surfaces

Thursday, November 3, 2005, 11:00 am, Room 311a

Session: Sugars at Surfaces
Presenter: G. Coullerez, Laboratory for Surface Science and Technology, Switzerland
Authors: G. Coullerez, Laboratory for Surface Science and Technology, Switzerland
K. Barth, Laboratory for Surface Science and Technology, Switzerland
M. Textor, Laboratory for Surface Science and Technology, Switzerland
Correspondent: Click to Email
Carbohydrates are information-rich molecules vital in intercellular interactions. As cell surface receptors, they play a role as recognition site for interactions with other cells, viruses or bacteria. To investigate those bio-interactions sugar tools based on carbohydrate chemistry and sensitive analytical techniques are needed. Functionalized surfaces with synthetic carbohydrate-tagged polymers that display multiple copies of the binding sugar units are attractive approaches to mimic interaction at cell-surfaces. They are often multivalent providing strength and specificity. In this aim, we have developed PEG-graft polycationic copolymers tagged saccharides. While spontaneously adsorbed on negatively charged surfaces the copolymers show specific lectin and bacteria recognition. Combined with a photolithography patterning method on metal oxide surfaces (Nb@sub 2@O@sub 5@, TiO@sub 2@), the high specificity of this platform in a non-fouling background is also demonstrated. The glycopolymers can also be synthesized with atom transfer radical polymerization (ATRP) of glycosylated monomers, featuring a wide range of functionalities, molecular weight and polydispersity for specific protein or cell-targeting applications. To demonstrate the versatility of our approaches, we use in particular the well-known mannose-lectin Concanavalin A (ConA) or bacteria E. Coli specific interactions. To sense in situ/in real time and quantitatively the interfacial processes between carbohydrate-modified surfaces and proteins in solution, fluorescence microscopy and optical evanescent field based sensor are used. The carbohydrate surface density is also quantitatively investigated by chemical surface analysis methods (XPS, ToF-SIMS). First applications and case studies using synthetic glycopolymers tagged with mono- or oligosaccharide will be discussed mainly in the context carbohydrate chips for proteins and pathogens detection and delivery vectors to target specific cell receptors.