A hydrogel product is comprising a chondroitin, molecule selected from the group consisting of chondroitin and chondroitin sulfate as the swellable polymer, wherein the chondroitin molecule is cross-linked into a network via its carboxyl groups. The hydrogel product can be prepared by a process comprising the steps of (a) providing chondroitin molecules; (b) activating the carboxyl groups on the chondroitin molecules with a triazine-based coupling reagent to form an activated, cross-linked chondroitin; and (c) cross-linking the activated chondroitin molecules via their carboxyl groups using a cross-linking agent. The hydrogel product is useful for treatment of soft tissue disorders.

The invention relates to a polysaccharide polymer of formula (I):

PS—(O—CO-L-X).sub.a(OH).sub.b   (I) in which PS denotes the basic backbone of the polysaccharide bearing the hydroxyl groups; L is a divalent hydrocarbon-based group comprising from 1 to 20 carbon atoms; X denotes a photoactive group of azide or diazirine type; a denotes the content of OH groups substituted with the photoactive group; b denotes the content of unsubstituted free OH groups; a being between 0.02 and 0.5; b being between 0.5 and 0.98; and a+b=1.

The invention also relates to a composition comprising the polymer (I) in a physiologically acceptable medium, and also to a cosmetic process for caring for the skin, comprising the topical application to the skin of said composition and exposure of the treated skin to light radiation.

The invention relates to a cosmetic process for caring for the skin, more particularly facial skin, in particular wrinkled skin, comprising the topical application to the skin of a cosmetic composition comprising a grafted polysaccharide polymer (I) and exposure of the treated skin to light radiation, polymer (I) being of formula:

PS—(CO—NH-L-X).sub.a(COOH)b

in which PS denotes the basic backbone of the polysaccharide bearing the carboxylic acid groups;
L is a divalent hydrocarbon-based group containing from 1 to 20 carbon atoms;
X denotes a photoactive group of azide or diazirine type;
a denotes the content of COOH groups substituted with the group —NH-L-X;
b denotes the content of unsubstituted free COOH groups;
a being between 0.01 and 0.8; b being between 0.2 and 0.99;
a+b=1

The invention also relates to the polymers (I) bearing a photoactive group X of diazirine type and to a composition comprising such a polymer in a physiologically acceptable medium.

Provided is a compound in which a group derived from chondroitin sulfate and a group derived from a steroid are covalently bonded together via a spacer represented by general formula (I). In the formula, m represents an integer of 0 or 1. Here, if m=0, R.sup.1 represents a group selected from the group consisting of electron-donating groups and steric hindrance groups. If m=1, R.sup.1 represents a group selected from the group consisting of a hydrogen atom, electron-donating groups and steric hindrance groups.

—HN—(CH.sub.2).sub.m—CHR.sup.1—CO—  (I)

A method for at least partial deacetylation of a biopolymer comprising acetyl groups, including: a1) providing a biopolymer including acetyl groups; a2) reacting the biopolymer including acetyl groups with hydroxylamine (NH.sub.2OH) or a salt thereof at a temperature of 100° C. or less for 2-200 hours to form an at least partially deacetylated biopolymer; and a3) recovering the at least partially deacetylated biopolymer.

The invention relates to glucosaminoglycan derivatives, endowed with heparanase inhibitory activity and antitumor activity, bearing carboxylate groups in positions 2 and 3 of at least part of the glucosaminoglycan residues, and to the process for preparing the same. The glucosaminoglycan derivatives of the present invention are generated starting from natural or synthetic glucosaminoglycans, preferably heparin or low molecular weight heparin, optionally 2-O- and 2N-desulfated by two steps of oxidation. By the first oxidation, adjacent diols and optionally adjacent OH/NH2 of the glucosaminoglycan residues are converted to aldehydes and by the second oxidation said dialdehydes are converted to carboxylate groups. The first oxidation preferably leads to the cleavage of C2-C3 linkage of the ring of oxidable residues. The invention further relates to a process for the preparation of said glucosaminoglycan derivatives and further to their use as active ingredients of medicaments. Furthermore, the invention relates to pharmaceutical compositions comprising di/tricarboxylated heparin derivatives, as active agent.

Process is described for extraction from a plant starting material, such as a fungus, for the preparation of a mixture (m) of at least one glycosaminoglycan selected from: (a) hyaluronic acid or a salt thereof (HA) having a weight average molecular weight from 10 kDa to 600 kDa; (b) chondroitin or chondroitin sulfate or a salt thereof (CS) having a weight average molecular weight comprised from 3 kDa to 50 kDa; and (c) a combination of (a) and (b).

A process for the preparation of a chondroitin sulphate salt with an average molecular weight (Mw) of 10-30 kDa via chemical sulphation of an unsulphated chondroitin backbone is provided. The unsulphated chondroitin can be obtained by acid hydrolysis of a capsular polysaccharide K4 made directly from E. coli strain O5:K4:H4 or directly produced from a genetically modified strain of E. coli. Sulphation of the N-acetyl-D-galactosamine residue at position 4 or 6 takes place simultaneously in the same polysaccharide chain, simulating the sulphation pattern observed in natural chondroitin sulphate.

A glycosaminoglycan derivative which is obtainable by a process that includes the steps of N-desulfation of from 25% to 100% of the N-sulfated residues of a glycosaminoglycan, and oxidation, by periodate at a pH of from 5.5 to 10.0, of from 25% to 100% of the 2-N-, 3-O-non-sulfated glucosamine residues, and of the 2-O-non-sulfated uronic acid residues of said glycosaminoglycan, under conditions effective to convert adjacent diols and adjacent OH/NH.sub.2 to aldehydes. The process further includes reduction, by sodium borohydride, of said oxidized glycosaminoglycan, under conditions effective to convert said aldehydes to alcohols, where the glycosaminoglycan is heparin, low molecular weight heparin, heparan sulfate or fractions thereof.

A hydrogel material composition includes: (1) an alginate (or other cross-linking polymer) material; (2) an optional α-hydroxy carboxylate material; and (3) an iron cation material. The hydrogel material composition with or without the α-hydroxy-carboxylate material may be used in a photolithographic imaging application or a photorelease application within the context of a photoirradiation induced reduction/oxidation reaction of an iron (III) cation material to form an iron (II) cation material.