Nonfouling amphiphilic polysaccharides

Stella Bauer, M.P. Arpa-Sancet, J. Finlay, N., Aldred, M.E. Callow, J.A. Callow, A.Rosenhahn

The potential of polysaccharides for fouling-resistant coatings lies in their chemical structure: due to the presence of ether- and hydroxyl-groups, they are highly hydropihilic and able to form water-storing hydrogels. In this study, the free carboxyl-groups of two surface-tethered polysaccharides, hyaluronic acid (HA) and chondroitin sulfate (CS) were postmodified with the hydrophobic trifluoroethylamine. This strategy was chosen to study different effects: a blocking of free carboxyl groups to prevent complexation of bivalent ions and to preserve the resistance of these coatings in the marine environment, a shifting of the contact angle towards the minimum in the Baier curve and the introduction of amphiphilic properties due to the hydrophobic fluoro-groups. The coatings were tested towards their protein resistance and with different fouling relevant species to evaluate their resistance properties. Settlement and adhesion strength of the marine bacteria Cobetia marina and the two algae species Ulva linza and Navicula perminuta were reduced by the modification in case of HA based coatings. However, in case of CS coatings, the adverse effect was observed.