Ionic polymer compositions

Abstract

The present disclosure pertains to ionic polymer compositions, including semi- and fully interpenetrating polymer networks, methods of making such ionic polymer compositions, articles made from such ionic polymer compositions, and methods of making such articles and packaging for such articles.

1 . An orthopedic implant comprising:
 a crosslinked ionic polymer comprising a plurality of sulfonic acid groups and a plurality of carboxylic acid groups, wherein the crosslinked polymer comprises   a first surface comprising a first concentration of sulfonic acid groups and a first concentration of carboxylic acid groups,   a second surface opposing the first surface, and   a bulk region therebetween comprising a second concentration of sulfonic acid groups and a second concentration of carboxylic acid groups,   wherein the first concentration of sulfonic acid groups is higher than the second concentration of sulfonic acid groups.   
     
     
         2 . The orthopedic implant of  claim 1 , wherein the orthopedic implant is adapted to form a prosthetic cartilage plug for at least partially replacing a surface of a joint. 
     
     
         3 . The orthopedic implant of  claim 1 , wherein the plurality of sulfonic acid groups renders the crosslinked ionic polymer increased lubricity with a decreased coefficient of friction compared to a second crosslinked ionic polymer having no sulfonic acid groups. 
     
     
         4 . The orthopedic implant of  claim 1 , wherein the crosslinked ionic polymer has a coefficient of friction less than 0.1. 
     
     
         5 . The orthopedic implant of  claim 4 , wherein the crosslinked ionic polymer has a coefficient of friction less than 0.05. 
     
     
         6 . The orthopedic implant of  claim 1 , wherein the second surface comprises a third concentration of sulfonic acid groups and a third concentration of carboxylic acid groups, and wherein the water forms a hydration gradient between two locations within the crosslinked polymer selected from the group consisting of the second surface and the bulk region, the first surface and the bulk region, and the first surface and the second surface. 
     
     
         7 . The orthopedic implant of  claim 6 , wherein the first concentration of sulfonic acid groups is at least 10% higher or at least 10% lower than the third concentration of sulfonic acid groups. 
     
     
         8 . The orthopedic implant of  claim 1 , wherein the first concentration of sulfonic acid groups is at least 10% higher than the second concentration of sulfonic acid groups. 
     
     
         9 . The orthopedic implant of  claim 1 , further comprising a coating disposed on at least one of the first surface and the second surface, wherein the coating is a bonding agent adapted to physically, chemically, or physicochemically adhere to the first surface or the second surface of the orthopedic implant. 
     
     
         10 . The orthopedic implant of  claim 9 , wherein the coating is a co-polymer of polymethylmethacrylate and urethane dimethacrylate. 
     
     
         11 . The orthopedic implant of  claim 1 , wherein the plurality of carboxylic acid groups is selected from a group consisting of underivatized acrylic acid monomers within the ionic polymer, underivatized methacrylic acid monomers within the ionic polymer, underivatized crotonic acid monomers within the ionic polymer, underivatized linolenic acid monomers within the ionic polymer, underivatized maleic acid monomers within the ionic polymer, and underivatized fumaric acid monomers within the ionic polymer, and wherein the amino-sulfonic acid groups correspond one or more of the following: amino-sulfonic-acid-derivatized acrylic acid monomers within the ionic polymer, amino-sulfonic-acid-derivatized methacrylic acid monomers within the ionic polymer amino-sulfonic-acid-derivatized crotonic acid monomers within the ionic polymer, amino-sulfonic-acid-derivatized linolenic acid monomers within the ionic polymer, amino-sulfonic-acid-derivatized maleic acid monomers within the ionic polymer, and amino-sulfonic-acid-derivatized fumaric acid monomers within the ionic polymer. 
     
     
         12 . An orthopedic implant comprising:
 a crosslinked ionic polymer comprising a plurality of sulfonic acid groups and a plurality of carboxylic acid groups, wherein the crosslinked polymer comprises   a first surface,   a second surface opposing the first surface, and   a bulk region therebetween,   wherein a first concentration gradient of the plurality of sulfonic acid groups and/or the plurality of carboxylic acid groups is formed between at least the first surface and the bulk region.   
     
     
         13 . The orthopedic implant of  claim 12 , wherein the orthopedic implant is adapted to form a prosthetic cartilage plug for at least partially replacing a surface of a joint. 
     
     
         14 . The orthopedic implant of  claim 12 , wherein the concentration gradient is adapted to provide at least one of a stiffness gradient and hydration gradient within the implant. 
     
     
         15 . The orthopedic implant of  claim 12 , wherein a concentration of the plurality of sulfonic acid groups in the first concentration gradient of the plurality of sulfonic acid groups increases with increasing distance from the first surface. 
     
     
         16 . The orthopedic implant of  claim 12 , wherein the first concentration gradient extends from the first surface to the second surface and wherein the a concentration of the plurality of sulfonic acid groups in the first concentration gradient of the plurality of sulfonic acid groups decreases between the bulk region and at least one of the first surface and the second surface. 
     
     
         17 . The orthopedic implant of  claim 12 , further comprising a coating disposed on at least one of the first surface and the second surface. 
     
     
         18 . The orthopedic implant of  claim 17 , wherein the coating is a bonding agent adapted to physically, chemically, or physicochemically adhere to the first surface or the second surface of the orthopedic implant. 
     
     
         19 . The orthopedic implant of  claim 17 , wherein the coating is a co-polymer of polymethylmethacrylate and urethane dimethacrylate. 
     
     
         20 . The orthopedic implant of  claim 12 , wherein the plurality of carboxylic acid groups is selected from a group consisting of underivatized acrylic acid monomers within the ionic polymer, underivatized methacrylic acid monomers within the ionic polymer, underivatized crotonic acid monomers within the ionic polymer, underivatized linolenic acid monomers within the ionic polymer, underivatized maleic acid monomers within the ionic polymer, and underivatized fumaric acid monomers within the ionic polymer, and wherein the amino-sulfonic acid groups correspond one or more of the following: amino-sulfonic-acid-derivatized acrylic acid monomers within the ionic polymer, amino-sulfonic-acid-derivatized methacrylic acid monomers within the ionic polymer amino-sulfonic-acid-derivatized crotonic acid monomers within the ionic polymer, amino-sulfonic-acid-derivatized linolenic acid monomers within the ionic polymer, amino-sulfonic-acid-derivatized maleic acid monomers within the ionic polymer, and amino-sulfonic-acid-derivatized fumaric acid monomers within the ionic polymer.