Characterization of protein-resistant dextran monolayers

A range of synthetic thiolated dextrans of varying molecular weights and de grees of thiol substitution have been investigated as well-defined monolaye r coatings for the reduction of nonspecific protein adsorption. Atomic forc e microscopy and surface plasmon resonance (SPR) analysis revealed that the surface coverage of the dextran monolayers increased with an increasing de gree of thiol substitution, but conversely decreased with increasing molecu lar weight. SPR was then employed to monitor bovine serum albumin protein a dsorption to thiolated dextran monolayers from a flowing buffered solution. Whilst a significant reduction of protein adsorption to a thiolated dextra n layer coated surface compared to an uncoated surface was observed, the de gree of conversion of hydroxyls to thiol groups and molecular weight was sh own to affect the protein-resistant performance of the dextran layer. (C) 2 000 Elsevier Science Ltd. All rights reserved.