Biodegradable single-phase cohesive hydrogels

Abstract

A biodegradable single-phase cohesive hydrogel includes a homogenous mixture of 2 to 5 identical or different polymers interpenetrating each other in a single phase, wherein the polymers are independently crosslinked prior to interpenetration by mixing, and the crosslinked polymers are insoluble in water and miscible with each other.

1 - 24 . (canceled) 
     
     
         25 . A biodegradable single-phase cohesive hydrogel, comprising:
 a homogenous mixture of 2 to 5 identical or different polymers interpenetrating each other in a single phase, wherein:   the polymers are independently crosslinked prior to interpenetration by mixing; and   the crosslinked polymers are insoluble in water and miscible with each other.   
     
     
         26 . The hydrogel according to  claim 25 , wherein the polymers have different degrees of crosslinking. 
     
     
         27 . The hydrogel according to  claim 25 , wherein the polymers have identical degrees of crosslinking. 
     
     
         28 . The hydrogel according to  claim 25 , wherein each polymer is a polysaccharide. 
     
     
         29 . The hydrogel according to  claim 28 , wherein each polysaccharide is selected from the group consisting of hyaluronic acid, keratan, heparin, cellulose, cellulose derivatives, alginic acid, xanthan, carrageenan, chitosan, chondroitin, and biologically acceptable salts thereof. 
     
     
         30 . The hydrogel according to  claim 28 , wherein each polysaccharide is hyaluronic acid or a biologically acceptable salt thereof. 
     
     
         31 . The hydrogel according to  claim 28 , wherein at least one polysaccharide is selected from the group consisting of cellulose derivatives and biologically acceptable salts thereof. 
     
     
         32 . The hydrogel according to  claim 28 , wherein at least one polysaccharide is selected from the group consisting of chondroitin and biologically acceptable salts thereof. 
     
     
         33 . The hydrogel according to  claim 28 , wherein at least one polysaccharide is selected from the group consisting of chitosan and biologically acceptable salts thereof. 
     
     
         34 . The hydrogel according to  claim 25 , wherein the homogenous mixture is of 2 polymers. 
     
     
         35 . The hydrogel according to  claim 25 , further comprising one or more active principles selected from the group consisting of antioxidants, antiseptics, anti-inflammatories, local anesthetics, and mixtures thereof. 
     
     
         36 . The hydrogel according to  claim 25 , further comprising at least one antioxidant selected from the group consisting of mannitol and sorbitol. 
     
     
         37 . The hydrogel according to  claim 25 , further comprising a local anesthetic. 
     
     
         38 . A kit comprising the hydrogel according to  claim 25  packaged in a sterile syringe. 
     
     
         39 . A process of preparing a biodegradable single-phase cohesive hydrogel, comprising:
 independently crosslinking 2 to 5 polymers to obtain 2 to 5 identical or different crosslinked polymers; and   interpenetrating the crosslinked polymers by mixing to obtain a homogenous mixture of the crosslinked polymers in a single phase,   wherein the crosslinked polymers are insoluble in water and miscible with each other.   
     
     
         40 . The process according to  claim 39 , wherein crosslinking is performed using a bi- or polyfunctional crosslinking agent selected from the group consisting of bi- or polyfunctional epoxy compounds and divinyl sulfone. 
     
     
         41 . The process according to  claim 39 , wherein each polymer has a degree of crosslinking within a range from 0.02 to 0.4. 
     
     
         42 . A method of cosmetic injection comprising injecting the hydrogel according to  claim 25  to fill a wrinkle, skin defect, or volume defect of a patient.