Method of soft tissue augmentation

Abstract

Particles according to the invention are made of a viscoelastic medium, are injectable gel particles, and have a size, when subjected to a physiological salt solution, in the range of from 1 to 5 mm. The particles are useful in a soft tissue augmentation implant. The implant comprises particles of a viscoelastic medium, wherein a major volume of the particles are injectable gel particles according to the invention. The implant is useful in a method of soft tissue augmentation in a mammal, including man, comprising subepidermal administration at a site in said mammal where soft tissue augmentation is desirable, of an implant according to the invention.

1 . A soft tissue augmentation implant comprising particles of a cross-linked hyaluronic acid, wherein said cross-linked hyaluronic acid is cross-linked with a cross-linking agent, wherein a major volume of said particles are injectable gel particles having a size, when subjected to a physiological salt solution, in the range of from 1.5 to 5 MM. 
     
     
         2 . A soft tissue augmentation implant according to  claim 1 , wherein said size is in the range of from 1.5 to 2.5 mm. 
     
     
         3 . A soft tissue augmentation implant according to  claim 1 , wherein said size is in the range of from 2.5 to 5 mm. 
     
     
         4 . A method of soft tissue augmentation in a mammal, including man, comprising subepidermal administration at a site in said mammal where soft tissue augmentation is desirable, of an implant comprising injectable gel particles of a viscoelastic medium, a major volume of said particles having a size, when subjected to a physiological salt solution, in the range of from 1 to 5 mm. 
     
     
         5 . A method according to  claim 4 , wherein said administration is subcutaneous administration. 
     
     
         6 . A method according to  claim 4 , wherein said administration is submuscular administration. 
     
     
         7 . A method according to  claim 4 , wherein said administration is supraperiostal administration. 
     
     
         8 . A method according to  claim 4 , wherein said size is in the range of from 1 to 2.5 mm. 
     
     
         9 . A method according to  claims 4 , wherein said size is in the range of from 2.5 to 5 mm. 
     
     
         10 . A method according to  claim 8 , wherein said site of soft tissue augmentation is selected from facial tissue and other tissues covered by exposed skin. 
     
     
         11 . A method according to  claim 4 , wherein said administration is a single administration. 
     
     
         12 . A method according to  claim 4 , wherein said administration is a multiple-layer administration. 
     
     
         13 . A soft tissue augmentation implant according to  claim 1 , wherein said cross-linking agent is selected from the group consisting of aldehydes, epoxides, polyaziridyl compounds, glycidyl ethers, and divinylsulfones. 
     
     
         14 . A soft tissue augmentation implant according to  claim 13 , wherein said cross-linking agent is an epoxide. 
     
     
         15 . A soft tissue augmentation implant according to  claim 14 , wherein said cross-linking agent is 1,4-butanediol diglycidyl ether. 
     
     
         16 . A soft tissue augmentation implant according to  claim 1 , wherein the concentration of the cross-linked hyaluronic acid in said gel particles, when subjected to a physiological salt solution, is in the range of from 15 to 30 mg/ml. 
     
     
         17 . A soft tissue augmentation implant according to  claim 16 , wherein the concentration of the cross-linked hyaluronic acid in said gel particles, when subjected to a physiological salt solution, is in the range of from 22 to 30 mg/ml. 
     
     
         18 . A soft tissue augmentation implant according to  claim 16 , wherein the concentration of the cross-linked hyaluronic acid in said gel particles, when subjected to a physiological salt solution, is in the range of from 20 to 25 mg/ml. 
     
     
         19 . A soft tissue augmentation implant according to  claim 1 , which are injectable through a 20 gauge or larger needle by application of a pressure of 15-50 N. 
     
     
         20 . A soft tissue augmentation implant according to  claim 1 , wherein removal of the implant is facilitated compared to an implant with smaller particles.