AMPHIPHILIC POLYSACCHARIDES AS INERT SURFACE COATINGS

Stella Bauer,^1,2 Maria P. Arpa Sancet,^1,2 John Finlay,³ Maureen E. Callow,³ James A. Callow,³ Nick Aldred,⁴ Anthony Clare⁴ and A. Rosenhahn^1,2

¹ Institute of Functional Interfaces, IFG, Karlsruhe Institute of Technology, Germany

² Applied Physical Chemistry, Ruprecht-Karls-University Heidelberg, Germany

³ School of Biosciences, University of Birmingham, United Kingdom

⁴ School of Marine Science and Technology, Newcastle University, United Kingdom

For the development of the next generation of foul release coatings it is important to explore new classes of nontoxic and nonfouling materials. The potential of polysaccharides as fouling-resistant coatings lies in their chemical structure: due to the presence of hydroxyl-groups, they are highly hydrophilic and able to form water-storing hydrogels. Their resistance against bacteria and mammalian cells was e.g. demonstrated by Morra and Cassinelli.¹ Cao et. al.² applied these materials to the marine environment and showed that different acidic polysaccharides have a high anti-fouling potential in terms of protein resistance, but loose this promising property in the marine environment. This collapse is caused by a complexation of bivalent cations like Ca²⁺.^2-3 In this study, the free carboxyl-groups of two polysaccharides, hyaluronic acid and chondroitin sulfate were postmodified with the hydrophobic trifluoroethylamine. With this strategy, different intentions could be realized: a blocking of free carboxyl groups to prevent complexation of ions and a preservation of the resistance in marine environment, a shifting of the contact angle towards the minimum in the Baier curve to maximize inert properties⁴ and the introduction of amphiphilic properties due to the hydrophobic fluoro-groups.⁵ Some of the coatings show very good protein resistance and a high resistance against a range of biofouling species.