Combination of cross-linked hyaluronic acids and method of preparing the same

Abstract

Provided are a method of preparing a cross-linked hyaluronic acid having an elasticity of about 50 to about 200 Pa and a viscosity of about 20 to about 100 Pa, including cross-linking hyaluronic acid with an epoxy-based cross-linking agent having at least two epoxy functional groups in an ethanol-containing aqueous alkaline; a method of preparing a cross-linked hyaluronic acid having an elasticity of about 400 to about 800 Pa and a viscosity of about 40 to about 100 Pa, including cross-linking the same cross-linked hyaluronic acid with the same epoxy-based cross-linking agent in an aqueous alkaline solution; and a combination of the cross-linked hyaluronic acids one having an elasticity of about 50 to about 200 Pa and a viscosity of about 20 to about 100 Pa and the other having an elasticity of about 400 to about 800 Pa and a viscosity of about 40 to about 100 Pa.

1 . A method of preparing a cross-linked hyaluronic acid having an elasticity of about 50 to about 200 Pa and a viscosity of about 20 to about 100 Pa, the method comprising cross-linking hyaluronic acid with an epoxy-based cross-linking agent having at least two epoxy functional groups in an ethanol-containing aqueous alkaline solution. 
     
     
         2 . A method of preparing a cross-linked hyaluronic acid having an elasticity of about 400 to about 800 Pa and a viscosity of about 40 to about 100 Pa, the method comprising further cross-linking the cross-linked hyaluronic acid prepared using the method of  claim 1  with an epoxy-based cross-linking agent having at least two epoxy functional groups in an aqueous alkaline solution. 
     
     
         3 . The method of  claim 1 , wherein the hyaluronic acid is obtained by fermentation with a microorganism. 
     
     
         4 . The method of  claim 1 , wherein the hyaluronic acid includes hyaluronic acid, a salt of hyaluronic acid, or any mixtures thereof. 
     
     
         5 . The method of  claim 4 , wherein the salt of hyaluronic acid is selected from the group consisting of sodium hyaluronate, potassium hyaluronate, magnesium hyaluronate, zinc hyaluronate, cobalt hyaluronate, tetrabutylammonium hyaluronate, and any combinations thereof. 
     
     
         6 . The method of  claim 1 , wherein the hyaluronic acid comprises sodium hyaluronate having a molecular weight of about 100,000 to about 6,000,000. 
     
     
         7 . The method of  claim 1 , wherein the epoxy-based cross-linking agent having at least two epoxy functional groups is selected from the group consisting of 1,4-butanediol diglycidyl ether (BDDE), ethylene glycol diglycidyl ether (EGDGE), 1,6-hexanediol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, polyglycerol polyglycidyl ether, digylcerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylpropane polyglycidyl ether, 1,2-(bis(2,3-epoxypropoxy)ethylene, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether, and any combinations thereof. 
     
     
         8 . The method of  claim 1 , wherein the ethanol-containing aqueous alkaline solution contains about 5 to about 13% w/w of ethanol. 
     
     
         9 . The method of  claim 1 , wherein the ethanol-containing aqueous alkaline solution is an aqueous sodium hydroxide solution of about 0.7 to 1.3% w/w containing about 5 to about 13% w/w of ethanol. 
     
     
         10 . A combination of cross-linked hyaluronic acids comprising a cross-linked hyaluronic acid having an elasticity of about 50 to about 200 Pa and a viscosity of about 20 to about 100 Pa, and a cross-linked hyaluronic acid having an elasticity of about 400 to about 800 Pa and a viscosity of about 40 to about 100 Pa. 
     
     
         11 . A combination of cross-linked hyaluronic acids, the combination comprising a cross-linked hyaluronic acid having an elasticity of about 50 to about 200 Pa and a viscosity of about 20 to about 100 Pa prepared by a method comprising cross-linking hyaluronic acid with an epoxy-based cross-linking agent having at least two epoxy functional groups in an ethanol-containing aqueous alkaline solution; and
 a cross-linked hyaluronic acid having an elasticity of about 400 to about 800 Pa and a viscosity of about 40 to about 100 Pa prepared by a method comprising cross-linking the cross-linked hyaluronic acid having an elasticity of about 50 to about 200 Pa and a viscosity of about 20 to about 100 Pa with an epoxy-based cross-linking agent having at least two epoxy functional groups in an aqueous alkaline solution.   
     
     
         12 . The combination of cross-linked hyaluronic acids of  claim 11 , the combination having an elasticity of about 100 to about 150 Pa and a viscosity of about 20 to about 60 Pa. 
     
     
         13 . The combination of cross-linked hyaluronic acids of  claim 12 , wherein the cross-linked hyaluronic acid having an elasticity of about 50 to about 200 Pa and a viscosity of about 20 to about 100 Pa and the cross-linked hyaluronic acid having an elasticity of about 400 to about 800 Pa and a viscosity of about 40 to about 100 Pa are combined in a weight ratio of about 8:2 to about 9:1. 
     
     
         14 . The combination of cross-linked hyaluronic acids of  claim 12 , wherein the combination of cross-linked hyaluronic acids is in the form of particles having an average particle size of about 500 to about 750 μm. 
     
     
         15 . A biocompatible material comprising the combination of cross-linked hyaluronic acids of  claim 10 . 
     
     
         16 . The biocompatible material of  claim 15 , wherein the biocompatible material is selected from the group consisting of arthritis treatment implants, wrinkle fillers, cosmetic fillers, and drug carriers. 
     
     
         17 .- 18 . (canceled)