Preparation of vinylated polysaccharides and photofabrication of tubular scaffolds as potential use in tissue engineering

Polysaccharides, such as heparin, hyaluronan, and chitosan, were partially derivatized with a styryl or a methacryloyl group by condensation at a carboxyl or an amino group of the polysaccharides with 4-vinylaniline or 4-vinylbenzoic acid. The degree of substitution depended on the reaction conditions. These compounds with low degrees of derivatization produced water-swollen hydrogels only at relatively high concentrations (30-40 wt %) in the presence of a carboxylated camphorquinone upon visible light irradiation. A high degree of derivatization of heparin increased the gel yield and concomitantly reduced the degree of swelling. The copolymerization of these vinylated polysaccharides with styrenated gelatin considerably reduced the degree of swelling. Tubular photoconstructs were prepared by photocopolymerization of vinylated polysaccharide and vinylated gelatin. The mixing of diacrylated poly(ethylene glycol) with vinylated polysaccharide improved the burst strength of photogels against the gradual infusion of water. These photocurable polysaccharides may be used as photocured scaffolds in tissue-engineered devices.