Nucleus Pulposus Filler

Abstract

The present invention provides a nucleus pulposus filler or the like which is to be packed into an area in deformed intervertebral disc wherein normal nucleus should be located and can be stabley maintained for a long time. More preferably, the present invention provides a nucleus pulposus filler comprising a crosslinked chondroitin sulfate as an active ingredient. The photocrosslinked chondroitin sulfate is preferably the following one: a photocrosslinked chondroitin sulfate obtainable by freezing a photoreactive chondroitin sulfate-containing solution comprising: a photoreactive chondroitin sulfate to which a photoreactive group is bound; an aqueous solvent capable of dissolving the photoreactive chondroitin sulfate; and any one substance selected from the group consisting of an alcohol having aqueous solvent miscibility, a surfactant, and a cheleting agent; irradiating the resulting frozen product with light; and then melting the frozen product. The filler can be provided as a kit by packing it into a container from which the filler can be pushed out.

1 . A nucleus pulposus filler comprising a crosslinked chondroitin sulfate as an active ingredient. 
     
     
         2 . The nucleus pulposus filler according to  claim 1 , wherein said crosslinking is photocrosslinking. 
     
     
         3 . The nucleus pulposus filler according to  claim 2 , wherein the photocrosslinked chondroitin sulfate is the following one:
 a photocrosslinked chondroitin sulfate obtainable by   freezing a photoreactive chondroitin sulfate-containing solution comprising: a   photoreactive chondroitin sulfate to which a photoreactive group is bound; an aqueous   solvent capable of dissolving the photoreactive chondroitin sulfate; and   any one substance selected from the group consisting of an alcohol having aqueous solvent miscibility, a surfactant, and a cheleting agent;   irradiating the resulting frozen product with light; and then   melting the frozen product.   
     
     
         4 . The nucleus pulposus filler according to  claim 3 , wherein the alcohol is an alcohol having a property of keeping a frozen state at a temperature of −7° C. or lower in the case that the alcohol is added to the aqueous solvent solution of the photoreactive chondroitin sulfate, the whole is frozen to obtain a frozen body, and then the temperature is elevated. 
     
     
         5 . The nucleus pulposus filler according to  claim 3 , wherein the alcohol is one represented by the following formula (I):
   R—OH  (1)   wherein R is selected from the group consisting of:   a linear alkyl having 1 to 10 carbon atoms,   a branched alkyl having 3 to 10 carbon atoms,   —CH 2 —(CHOH) l —CH 2 OH, wherein 1 is an integer of 0 to 5,   
       
         
           
           
               
               
           
         
         wherein m is an integer of 3 to 5, and 
         —(CH 2 CH 2 O) n —H, wherein n is an integer of 3 to 70. 
       
     
     
         6 . The nucleus pulposus filler according to  claim 3 , wherein the surfactant is a nonionic surfactant or an anionic surfactant. 
     
     
         7 . The nucleus pulposus filler according to  claim 6 , wherein the nonionic surfactant is polyethylene glycol, and the anionic surfactant is an alkyl sulfate salt. 
     
     
         8 . The nucleus pulposus filler according to  claim 3 , wherein the cheleting agent is an oxycarboxylic acid or a polyaminocarboxylic acid. 
     
     
         9 . The nucleus pulposus filler according to  claim 8 , wherein the oxycarboxylic acid is citric acid or a salt thereof, and the polyaminocarboxylic acid is ethylenediamine tetraacetic acid. 
     
     
         10 . The nucleus pulposus filler according to any one of  claim 1 , wherein the chondroitin sulfate has a weight average molecular weight of 10,000 to 100,000. 
     
     
         11 . The nucleus pulposus filler according to any one of  claim 3 , wherein the photoreactive group in the photoreactive chondroitin sulfate is bound to a carboxyl group of the chondroitin sulfate. 
     
     
         12 . The nucleus pulposus filler according to any one of  claim 3 , wherein the photoreactive chondroitin sulfate is contained in an amount of 1 to 20% by weight in the photoreactive chondroitin sulfate-containing solution. 
     
     
         13 . The nucleus pulposus filler according to any one of  claim 1 , wherein the crosslinked chondroitin sulfate has the following properties:
 viscosity measured under conditions of 20° C. and standard corn 0 degree) by means of a rotary viscosimeter is from 300 to 30,000 mPa·S and the chondroitin sulfate shows a gel form.   
     
     
         14 . The nucleus pulposus filler according to any one of  claim 1 , wherein the filler is administrated by injection. 
     
     
         15 . The nucleus pulposus filler according to any one of  claim 1 , which is used for regeneration of nucleus pulposus. 
     
     
         16 . A nucleus pulposus filler kit comprising the filler according to  claim 1  and a container from which the filler can be pushed out, wherein the filler is packed into the container.