The invention relates to the preparation and the use of α,β-unsaturated aldehydes in the structure of sulfated polysaccharides. It concerns the derivatives with a conjugated double bond in the 4th and 5th positions of the galactopyranose part situated in the 6th position with respect to the aldehyde, according to the general structural formula (I) or its hydrated form according to the general structural formula (II). The preparation of these derivatives derives from sulfated polysaccharides containing a galactopyranose ring sulfated in the 4th position that is bound in the polymer chain via α(1→3) or β(1→3) O-glycosidic bond. In the described solution, the sulfated polysaccharides undergo a regio- and chemoselective oxidation to form C6-saturated aldehyde, which, via a direct elimination of the sulfate group, provides the α,β- unsaturated derivative according to the general formula (I) or (II). The described solution is technically advantageous, because it leads directly to α,β-unsaturated aldehydes, without any elimination agents, higher temperature, or isolation of intermediates during the synthesis. The conjugation in the structure of α,β-unsaturated aldehyde allows, under physiological conditions, to bind a wide variety of biocompatible amines in the structure of the sulfated polysaccharides. The proposed method allows to prepare materials suitable for pH-responsive drug delivery systems, or for the preparation of scaffolds in tissue engineering or regenerative medicine. Formulae for the abstract (I), (II) above, where R is OH, O-SO2-OH, O-SO2-ONa, or NH-Ac.L'invention concerne la préparation et l'utilisation d'aldéhydes α,β-insaturés dans la structure de polysaccharides sulfatés. L'invention concerne les dérivés comportant une double liaison conjuguée en 4ème et 5ème positions de la partie galactopyranose située en 6ème position par rapport à l'aldéhyde, selon la formule structurelle générale (I) ou sa forme hydratée selon la formule structurelle générale (II).
