Design, preparation and characterization of ulvan based thermosensitive hydrogels

The present study is focused on the exploitation and conversion of sulphated polysaccharides obtainedfrom waste algal biomass into high value added material for biomedical applications. ulvan, a sulphatedpolysaccharide extracted from green seaweeds belonging to Ulva sp. was selected as a suitable materialdue to its chemical versatility and widely ascertained bioactivity. To date the present work representsthe first successful attempt of preparation of ulvan-based hydrogels displaying thermogelling behaviour.ulvan was provided with thermogelling properties by grafting poly(N-isopropylacrylamide) chains ontoits backbone as thermosensitive component. To this aim ulvan was properly modified with acryloylgroups to act as macroinitiator in the radical polymerization of N-isopropylacrylamide, induced by UVirradiation through a “grafting from” method. The thermogelling properties of the copolymer were inves-tigated by thermal and rheological analyses. Sol–gel transition of the copolymer was found to occur at30–31◦C thus indicating the feasibility of ulvan for being used as in-situ hydrogel forming systems forbiomedical applications