Abstract: The invention relates to the preparation and use of ?,?-unsaturated aldehyde of hyaluronan having a double bond in the positions 4 and 5 and an aldehydic group in the position 6 of the glucosamine part of the polysaccharide. The method of preparation is based on dehydration of hyaluronan having an aldehydic group in the position 6 of the glucosamine part of the polysaccharide. Two methods have been described, which are dehydration in a solution or heating in solid state in absence of solvents, bases or other additives. This derivative allows stabilization of conjugates of hyaluronan with amino compounds by means of a multiple bond from the aldehyde side, and therefore, it is possible to effectively immobilize practically any compound containing an amino group to such modified hyaluronan in physiological conditions. In case of using a diamine or compounds or polymers containing three or more amino groups, it is possible to prepare crosslinked hyaluronan derivatives.

Abstract: The subject-matter of the invention is a photoreactive derivative of hyaluronic acid (formula I) and the method of preparation thereof, where first an aldehyde derivative of hyaluronic acid is prepared, oxidized in the position 6 of the glucosamine cycle and then the oxidized derivative reacts with an amine carrying a photoreactive species, for example 1-(2-aminoethyl)pyridine-2(1H)-one, in the presence of a reducing agent, forming a photoreactive derivative. The prepared photoreactive derivative may be then photocrosslinked, wherein the reaction is based on [4+4] photocycloaddition.

Abstract: The invention relates to the preparation and use of ?,?-unsaturated aldehyde of hyaluronan having a double bond in the positions 4 and 5 and an aldehydic group in the position 6 of the glucosamine part of the polysaccharide. The method of preparation is based on dehydration of hyaluronan having an aldehydic group in the position 6 of the glucosamine part of the polysaccharide. Two methods have been described, which are dehydration in a solution or heating in solid state in absence of solvents, bases or other additives. This derivative allows stabilization of conjugates of hyaluronan with amino compounds by means of a multiple bond from the aldehyde side, and therefore, it is possible to effectively immobilize practically any compound containing an amino group to such modified hyaluronan in physiological conditions. In case of using a diamine or compounds or polymers containing three or more amino groups, it is possible to prepare crosslinked hyaluronan derivatives.