Polysaccharide compositions for use in tissue augmentation

Abstract

A composition of matter and method for preparation of a tissue augmentation material. A polysaccharide gel composition is prepared with a programmable rheology for a particular selected application. The method includes preparing a polymeric polysaccharide in a buffer to create a polymer solution or gel suspending particles in the gel and selecting a rheology profile for the desired tissue region.

1 . A method of preparing an implant having viscoelastic mechanical properties selected to match tissue at a site of implantation, the method comprising: 
 preparing a polymeric polysaccharide in a buffer to create a polysaccharide polymer solution or gel;    preparing a plurality of ceramic particles, the ceramic particles having a size range of about 20 microns to about 200 microns;    suspending the plurality of ceramic particles in the polysaccharide gel forming an implant having a concentration of particles of about 5% to about 65%; by volume;    selecting a rheological profile for the implant, the rheological profile selection based on rheological properties of the tissue at the site of implantation; and    adjusting rheological properties of the implant to the selected rheology profile, wherein the implant exhibits similar biomechanical behavior as the tissue into which it is implanted.    
   
   
       2 . The method of  claim 1 , wherein the polysaccharide polymer is selected from the group consisting of a cellulose polysaccharide and a hemicellulose polysaccharide.  
   
   
       3 . The method of  claim 1 , wherein the polysaccharide polymer is selected from the group consisting of: sodium carboxymethylcellulose, hydroxyethyl cellulose, ethylhydroxyethyl cellulose, carboxymethyl cellulose, carboxyethylhydroxyethyl cellulose, hydroxypropylhydroxyethyl cellulose, methyl cellulose, methylhydroxylmethyl cellulose, methylhydroxyethyl cellulose, carboxymethylmethyl cellulose, and modified derivatives thereof.  
   
   
       4 . The method of  claim 1 , wherein the adjusting of the ionic properties involves adjusting the pH of the solution to about 6.8 to about 8.0.  
   
   
       5 . The method of  claim 1 , wherein the particles have a size range of about 20 to about 200 microns.  
   
   
       6 . The method of  claim 1 , wherein the particles have a size range of about 20 to about 120 microns  
   
   
       7 . The method of  claim 1 , wherein the particles have a size range of about 20 to about 45 microns  
   
   
       8 . The method of  claim 1 , wherein the implant comprises about 5 to about 65% (by weight) of the particles  
   
   
       9 . The method of  claim 1 , wherein the implant comprises about 10 to about 50% (by weight) of the particles  
   
   
       10 . The method of  claim 1 , wherein the implant comprises about 30 to about 45% (by weight) of the particles  
   
   
       11 . The method of  claim 1 , wherein the gel comprises about 0.1 to about 10% (by weight) CMC.  
   
   
       12 . The method of  claim 1 , wherein the gel comprises about 1.5 to about 5% (by weight) CMC.  
   
   
       13 . The method of  claim 1 , wherein the gel comprises about 0.1 to about 5% (by weight) of a plasticizer.  
   
   
       14 . The method of  claim 1 , wherein the gel comprises a first polymer and a second polymer  
   
   
       15 . The method of  claim 1 , wherein the first polymer and the second polymer may form crosslinks there between or act individually on the material performance.  
   
   
       16 . The method of  claim 1 , wherein the implant has an osmolarity of between about 255 mOs and about 600 mOs.  
   
   
       17 . The method of  claim 1 , wherein the implant has an osmolarity of between about 255 mOs and about 327 mOs.  
   
   
       18 . The method of  claim 1 , wherein the implant has an osmolarity of between about 280 mOs and about 303 mOs.  
   
   
       19 . The method of  claim 1 , wherein the implant comprises between about 57.9% to about 70.3% (by weight) of water.  
   
   
       20 . The method of  claim 1 , wherein the tan δ of the implant is between about 0.5 to about 3.5.  
   
   
       21 . The method of  claim 1 , wherein the tan δ of the implant is between about 0.5 to about 2.0  
   
   
       22 . A composite material for tissue augmentation comprising: 
 a gel having suspended particles therein;    the injectable gel having a tan δ between about 0.5 and about 1 as measured at 0.65 Hz (3.8 rad/sec) and a osmolality of less than about 600 mOs.    
   
   
       23 . An article implanted in a human, the article comprising: 
 a gel, the gel including carboxymethylcellulose in a concentration of 0.1% to 10% and having less than 5% by weight glycerin;    a plurality of particles, the particles being biocompatible and having a particle size of less than 200 microns;    the plurality of particles suspended in the gel such that the gel acts as a carrier for the particles;    the implant having predetermined biomechanical properties,    wherein the predetermined biomechanical properties of the implant in vivo are substantially similar to those of tissue into which the implant is injected.    
   
   
       24 . The article of  claim 23 , wherein the tissue is lip tissue and further wherein the article provides a smooth, continuous flow into muscle and connective tissue surrounding the lip.  
   
   
       25 . The article of  claim 24 , wherein the particles are substantially homogenously suspended and do not form concentrated pockets of particles when implanted.  
   
   
       26 . The article of  claim 24 , wherein the gel comprises a range of biomechanical properties to match a range of those of the lip tissue.  
   
   
       27 . A system for augmentation of tissue, the system comprising: 
 a syringe and a needle attached thereto;    an injectable implant, the injectable implant comprising a polysaccharide gel having suspended ceramic particles therein;    the polysaccharide gel comprising carboxymethylcellulose in a concentration of 0.1% to 10% and having less than 5% by weight glycerin;    the ceramic particles being biocompatible and having a particle size of less than 200 microns;    the injectable gel is shear thinning and having a viscoelastic profile, the viscoelastic profile having a viscosity modulus of between 100 mPas and 3000 mPas and and an elasticity modulus between 150 mPas and 2900 mPas,    the viscoelastic profile selected to substantially match that of the tissue,    wherein the injectable gel is extrudable through the needle forming a tissue augmentation implant that exhibits biomechanical properties similar to that of the tissue.    
   
   
       28 . A biocompatible implant for a patient site comprising, 
 a particle mass; and    a biocompatible carrier for suspending the particle mass to be implanted into the patient site which has selected biochemical and biomechanical characteristic patient site properties and the biocompatible carrier having its characteristic biochemical and biomechanical properties matching the characteristic patient site properties such that the biocompatible implant remains mechanically stable at the site and has an exterior cosmetic appearance the same as the tissue site without cosmetic phase separation.    
   
   
       29 . The biocompatible implant as defined in  claim 28  wherein the biocompatible carrier includes a tan δ the same as the surrounding patient site.