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A novel and simple method for grafting one monolayer of hyaluronan (hyal) to glass surfaces is presented. The aim of the present study was to prepare polysaccharide layers with a well-defined chemistry for a better understanding of the biological properties of hyal bound to a substrate.
A reaction was carried out in solution to conjugate a silane alkylic chain with hyal. The elemental analysis of the modified polysaccharide (hyal-sil) indicates that one out of five disaccharide units is conjugated with the alkyl silane chain. The derivatised polysaccharide was let spontaneously assemble to a glass surface.
The grafted film was characterized by means of x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Angle resolved XPS measurements show that the hyal-sil film covers completely the substrate surface. On the basis of the XPS data the thickness of the hyal-sil film turns out to be 2 ± 0.5 nm. The AFM images of the hyal-sil monolayer are consistent with the XPS results revealing an uniform and rather smooth coated surface. Preliminary results show that fibroblasts do not adhere at all on hyal-sil modified surfaces whereas a good cell adhesion is observed, as expected, on bare glass surfaces.
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