Patent ID: 8512752

Claim:
A process for the preparation of crosslinked derivatives of polycarboxylated polysaccharides, wherein at least one of the polysaccharide chains consists of a derivative of hyaluronic acid, crosslinked by means of “click chemistry”-type reactions, said process comprising the following phases: i) preparing partial ester, amide, thioester or anhydride derivatives of polycarboxylated polysaccharides comprising (a) a type (a) residue being a 1,3-unsaturated or a 1,3-dipole group, and (b) a type (b) residue being a dienophile or a dipolarophile group; and ii) reacting at least two products of step i), one comprising a polycarboxylated polysaccharide comprising a 1,3-unsaturated group and one comprising a polycarboxylated polysaccharided comprising a dienophile group, or one comprising a polycarboxylated polysaccharide comprising a 1,3-dipole group and one comprising a polycarboxylated polysaccharide comprising a dipolarophile group in a cycloaddition reaction to form covalent bonds between two chains of said polycarboxylated polysaccharides; wherein: said 1,3-unsaturated group is a member selected from the group consisting of 1,3-butadiene, 1-methoxy-3-trimethylsilyloxy-1,3-butadiene, cyclopentadiene, cyclohexadiene, and furan; said dienophile is selected from alkenes, alkynes or derivatives of alkenes or alkynes with one or more electron-attractor groups linked to the double or triple bond; said 1,3-dipole group is selected from derivatives of nitrile-oxides, azides, diazo-alkanes, allenes and nitrones; and said dipolarophile is selected from alkenes, alkynes or derivatives of alkenes or alkynes with one or more electron-attractor groups bound to the double or triple bond.