Crosslinked carboxy polysaccharides

Claim 1

A cross-linked hyaluronic acid product wherein the first portion of 1-100% of the carboxyl groups of said hyaluronic acid are cross-linked by ester bonding or lactonic bonding to hydroxyl groups of the same hyaluronic acid molecule and/or to hydroxyl groups of different hyaluronic acid molecules; and the second portion of carboxyl groups if present of said hyaluronic acid are esterified with aliphatic, araliphatic, cycloaliphatic or heterocyclic alcohols, wherein said alcohols of the aliphatic series have a maximum of 34 carbon atoms and may be substituted by one or two functional groups chosen from the group formed by amino, hydroxy, mercapto, aldehydo, ketal, carboxy, hydrocarbyl, and dihydrocarbylamino, ether, ester, thioester, acetal, ketal, carbamidic groups or carbamidic groups substituted by one or more alkyl groups, the hycrocarbyl radicals in these groups having a maximum of 6 functionally modified carbon atoms, and in which such alcohols of the aliphatic series may be interrupted in the carbon atom chain by heteroatoms chosen from the group formed by oxygen, sulfur and nitrogen, and wherein said alcohols of the araliphatic series have only one benzene residue and have an aliphatic chain with a maximum of 4 carbon atoms and wherein the benzene residue may be substituted by between 1 and 3 methyl or hydroxy groups, by halogen atoms, and wherein the aliphatic chain may be substituted by one or two functions chosen from the group consisting of free amino groups or mono- or diethyl groups or by pyrrolidine or piperidine groups, said alcohols of the cycloaliphatic or aliphatic-cycloaliphatic series are mono- or polycyclic hydrocarbons with a maximum of 34 carbon atoms, and said heterocyclic alcohols are mono- or polycyclic cycloaliphatic or aliphatic cycloaliphatic alcohols interrupted in their carbon atom chain or ring by one or more heteroatoms chosen from the group formed by nitrogen, oxygen and sulfur, or wherein the alcohols of the cycloaliphatic or aliphatic cycloaliphatic series are derived from mono or polycyclic carbohydrates, and have a maximum of 34 carbon atoms, and may be unsubstituted and may contain one or more substituents, mentioned above for the aliphatic alcohols, or the aliphatic-cycloaliphatic polycyclic alcohols sterols, cholic acids and steroids, or wherein the heterocyclic alcohols are derivatives of the abovesaid cycloaliphatic or aliphatic-cycloaliphatic alcohols, wherein the linear or cyclic chains are interrupted by one to three hetereo atoms chosen from the group formed by - O -, - S -, - N and -NH, as well as genins, digitoxigenin, gitoxigenin, digoxigenin, strophanthidin, tigogenin saponins and vitamin alcohols; and the third portion of carboxyl groups if present is either salified or in form of the free acid.