Abstract: Disclosed are highly resilient and cohesive gels formed by the cross-linking of hyaluronan or hylan, their salts or derivatives thereof, using divinyl sulfone (DVS) as the cross-linking agent. Also disclosed are viscoelastic fluids containing alkylsulfone groups covalently attached to the backbone of the polymer, formed by the mono-functionalization of the cross-linking monomer DVS with hyaluronan and/or hylan. Mechanical properties such as values of hardness and cohesiveness are specified by the rheological properties of the gels. Also disclosed are methods for the preparation of such products. They have use in many applications as injectable and/or implantable devices and as drug delivery systems.

Abstract: The present invention provides for compositions of hyaluronic acid cross-linked with at least one other hydrophobic polymer to form a copolymer gel. The preferred composition is a formulation containing hyaluronic acid or its derivatives and a silicone base polymer with a functional group capable of reacting with the preferred cross-linker. The silicon may also be a group capable of undergoing further polymerization, or a silicone moiety adding to the hydrophobic nature of the gel. The product can be used alone or contain various other substances or covalently bound substances for numerous useful applications including cosmetic, medical, and drug delivery applications. The present invention also provides processes for preparing them.

Abstract: Disclosed are highly resilient and cohesive gels formed by the cross-linking of hyaluronan or hylan, their salts or derivatives thereof, using divinyl sulfone (DVS) as the cross-linking agent. Also disclosed are viscoelastic fluids containing alkylsulfone groups covalently attached to the backbone of the polymer, formed by the mono-functionalization of the cross-linking monomer DVS with hyaluronan and/or hylan. Mechanical properties such as values of hardness and cohesiveness are specified by the rheological properties of the gels. Also disclosed are methods for the preparation of such products. They have use in many applications as injectable and/or implantable devices and as drug delivery systems.

Abstract: Disclosed are biocompatible viscoelastic gel slurries formed from a polymeric gel, preferably a hyaluronan or a derivative thereof such as hylan swollen in an aqueous medium and a fluid phase which is an aqueous solution of a polymer which may also but not necessarily be a hyaluronan or derivative thereof. Also disclosed are methods of making such slurries, controlling their rheological properties and the uses thereof.

Abstract: Disclosed are biocompatible viscoelastic gel slurries formed from a polymeric gel, preferably a hyaluronan or a derivative thereof such as hylan swollen in an aqueous medium and a fluid phase which is an aqueous solution of a polymer which may also but not necessarily be a hyaluronan or derivative thereof. Also disclosed are methods of making such slurries, controlling their rheological properties and the uses thereof.

Abstract: Disclosed is hylan, a chemically modified hyaluronan preparation characterized by the presence of small amounts (0.0002-0.05% by weight) of aldehyde cross-linking groups covalently bonded to the hyaluronan molecular chains. Also disclosed is an improved method of obtaining hylan comprising treating hyaluronan in situ in animal tissues containing same with a treatment mixture including an aldehyde which is reactive towards hyaluronic acid and the proteins contained in the animal tissue. Treatment is effected at temperatures below about 16.degree. C. at very high pH, e.g., 8-14 whereby the overall yield is increased while maintaining the high molecular weight of the hylan.

Abstract: Disclosed is hylan, a chemically modified hyaluronic acid preparation characterized by the presence of small amounts (0.005-0.05% by weight) of aldehyde cross-linking groups covalently bonded to the hyaluronic acid molecular chains. Also disclosed is a method of obtaining hylan comprising treating hyaluronic acid in situ in animal tissues containing same with a treatment mixture including a reagent (typically an aldehyde) which is reactive towards hyaluronic acid and the proteins contained in the animal tissue.